I didn't know about batteries charging at different rates due to internal resistance. This was really great info and something everyone should know when parallel charging.
+Captain S Awesome! There is still some debate as to whether it is the IR or some other characteristic that is causing the different current between the packs, but the takeaway is that you can't assume that each pack is taking the same C rate of charge in a parallel configuration.
You all probably dont give a damn but does anybody know a trick to get back into an instagram account? I was stupid forgot my login password. I would appreciate any assistance you can give me.
Great video. I always used to charge my LiPos in parallel. Never had any issues. Only thing I did not pay attention to was the voltage of each battery. So I charged batteries of different voltages together and never checked before how much difference there was. Never had any issue though. Probably I only was lucky. Will pay attention to that from now on. And I never waited for them to equalize their charges. I plugged them in and started the charging. Never had any issues so far, but will change my habits and follow your advice, which I think is a pretty good one. So thanks a lot for your efforts and for your great videos. I learned a lot from watching them, not only today ;)
just started parallel charging my 6s lipo's i use in my 700 heli. and i like it so much i do it with all my lipo's now. I fly using telemetry and timer so my cells are very close to one other. and with the 700 i use the lipo's as a 12s pack so it's almost recommend to parallel charge them and i numbered them so they stay together. it is such a time saver charging 10 6s like this instead of all of them separately.
+MicroRCFiend There seems to be some debate as to whether it depends on IR or some other factor, but I don't think there is any debating that some batteries are taking more current than others. So if your goal is to stay under a certain rate, you can't simply multiply that rate by the number of batteries to get your charge rate.
+Andrew Demczuk I have used a current meter to measure how long it takes them to even out after plugging in to the board. There can be an initial rush of current as much as 5 amps, but it quickly dies down to below 1-2 amps. I don't think there is any danger to starting charging before they have perfectly evened out. If there is some residual voltage difference between them when charging starts, they will take current at various rates depending on their state of charge. It will all work out in the end. As shown in this video, even when the packs were perfectly even, there will still be significant current difference between them due to other factors. I believe that the reason people plug in the discharge leads first is to avoid sending high current down the relatively small balance lead wires. If you were to plug in batteries with a big enough voltage difference, and if you were to plug in the balance leads first, you could burn a wire or a trace on your board. By letting the batteries equalize over the discharge leads, you protect against this scenario. But of course you can--AND SHOULD--just use a battery checker to ensure that your packs are not more than 0.1 volts per cell off from each other, and you should be okay. Also, check the state of balance of the packs to ensure that a wildly out of balance pack is not going to create a bigger voltage difference than is apparent from the pack voltage.
Joshua - My personal recommendation is to ALWAYS balance charge with LiPos. EVERY TIME. They can get out of balance much too quickly, especially the way we abuse them on our little quadcopters. They actually beat on a pack as hard, if not harder than, big 3D helis do. The reason there is a question of being able to parallel charge and balance charge is this: If a person DOESN'T check as carefully as you do EVERY TIME, is that if you have too many packs too far out of balance, even after allowing them to equalize as you've done, there will come a time when the limited amount of current capacity - typically around 200-500mA - that most LiPo charger balancing circuits can manage will be exceeded, and the packs don't balance out properly before the charge cycle cuts out on max voltage. Many cheap LiPo chargers will not even alarm on this state! This imbalance is a thing that tends multiply quickly; a few cycles and you can have packs so far out of balance they NEVER get a chance to charge properly, and they CAN damage the balancing circuit in your charger. Always, ALWAYS re-balance charge a pack that is severely out of balance (My tester alarms at more than 0.05V difference between cells, though I like your limit of 0.04V better) BY ITSELF!!! Thanks for spreading the word about LiPo safety! Please, PLEASE go back to using a chargebox setup though... charging on a bare benchtop (*cringe*) is BEGGING Murphy to make an example of you!
+mnemennth Honestly, you should always balance charge all your packs, maybe except when at the field and trying to get back in the air. But that should only be a time or two.
Small question. Since the XT60 side was still connected when checking for the 2nd time, weren't you measuring the "average" of them all...since they're still connected in parallel essentially...which is why the measurement was identical. What about disconnecting them completely? Just curious...I always parallel balance charge and have never had an issue.
@ 3:45 of the video when you measured from the balance lead...the XT60 side of the same battery was still plugged into the balance board...so you're measuring the average of all the batteries still connected to the board. That's why they were identical. If you uplug the Xt60 side also before measuring then you will be seeing only that batteries measurement. I asked as a question, because maybe I'm missing something obvious here?
Some chargers do only charge trough the balance leads. You could try using such one, as they should not charge a cell that is higher than another. I have 2 of these that can charge 2-4 cell batteries and they work grate.
Hi you seem to really know your stuff, I am having a problem parallel charging, I have an EOS 1420i charger, now the charger is a 7 cell charger, and the balance cable normally plugs into these balance boards that came with the charger so if you have a 2s battery you plug it into the 2s port etc. Now I bought a parallel board that charges up to 4s packs, now it does not directly plug into my charger cause the balance cable is for 7s, so I use one of the balance boards and plug the parallel board into the balance board of my charger and that goes into the charger, and it seems to work, issue is I have to do 2-3 charging cycles to fully charge the batteries, cycle one might get it to 30-40 percent then cycle 2 gets usually 100 percent , why???? In one cycle it never gets the batteries fully charged. The batteries do stay cold and I mean dead cold while charging, they never never get warm, and even after 2 - 3 times back to back they never get warm, but they do get charged. The charge time 1st round is about 18min, the next time charge is only about 10-15 min. Then it is fully charged. My parallel board is a 5 battery 2-3-4s board, so it plugs into the 6s port of the balance board of my charger then into my charger. It seems logical and like I said it does work, very irritating that I need to have it do 2 charges to get the batteries to full. Can any one help, I would be willing to skype with some one to show you the setup, the only diff between most guys doing it is I am using a balance board that came with my charger as the balance cable that if in my charger is for up to 7s, and the boards that came with it go 2,3,4,5,6,7s ports, now I assume since my parallel board has 5 battery ports that is why it plugs into the 6s on the battery balance board of my charger. The charger for sure sees the balance cable cause if I do not plug in the balance cable it screams it does not have the balance cable in. It does work, just not like I wish it would. Can anyone help.
Great video Joshua. There is one aspect about parallel charging I've always been curious about: What would happen if you mix in a li-po with a bad cell?
+Jaap Pieroen If the cell was under-volt, then the other batteries would pump current into that cell until their voltages equalized. Depending on how bad the cell was, it could pull the other batteries down to its level and ruin their cells as well. If the cell is within safe voltage range for parallel charging, but has a very high IR, I believe the way it will work is this: the high IR will mean that more current will be required to raise its voltage. Therefore, it will take more current than the other packs on the board. This is kind of counter-intuitive, because usually with Ohm's law, higher resistance means lower current. But I think it is correct. The higher-resistance cell requires more current to raise its electro-chemical energy state, because more of the current is wasted as heat. Anyway, I'm not 100% sure on this, but it feels correct. So if I am correct about that, then what it means is that the higher IR cell will be charged at a higher C rating than the lower IR cells, which could exacerbate any damage that was done to it. This is one of the main things I wanted to point out in this video. If you parallel charge, you need to pay close attention to the health of your packs and to your charge rates, because careless parallel charging can make a marginal cell go bad very quickly. This may be one reason why people say that parallel charging ruins batteries and isn't safe. I say that it's just another aspect of parallel charging that you need to be aware of.
+Joshua Bardwell FWIW I've been parallel charging for over a year now, and wouldn't want to do it any other way. I never considered what effect different IR ratings could have over the current spread. So your video was pretty valuable for me. Maybe I should buy a clamp meter, I hope it comes packaged with an pearl. I have a fixed workflow for my batteries. When I go out flying I try to empty all my packs. When I'm back home I give every li-po a storage charge (I try to do that in parallel as well, but my li-po's tend to have too much voltage difference to do it in one go). This way I have a stack of li-po's with the same voltage, ready for my next flying day whenever that might be. Once I know I'll be flying I can hook all li-po's in parallel divided over my two chargers and be set to go in one hour. Meanwhile the li-po's are stored on the optimal voltage extending their lifetime.
+Jaap Pieroen Especially if you fly mini quads, parallel charging is the only way to charge in a reasonable amount of time, and for a reasonable amount of money. If you fly a 6S 10,000 mAh battery, then one big massive charger is useful to you. But if you fly ten 1300 mAh 4S batteries, what are you going to do? What you really need is 10x 50 watt chargers if you want to avoid parallel charging and still charge at 2C. Even if you went with the cheapest option (Accucel 6 50 watt) you're looking at $250. By going to parallel charging, you can make use of a top-of-the-line charger. But there are definitely some hoops you have to jump through to make it safe.
para balance charging is perfectly fine I have been doing it since balance boards first came out.. if the batteries are within a tenth of a volt or so they will equalize while charging with no wait time for them to do so and be perfectly fine.. if there is a 3 tenth volt difference between packs then I would start thinking about not charging that pack in that batch but .05 to .1 volt difference will work its self out during charge, now like I said if a pack is .2 to .3 or more different then charge that pack by its self.
and this is why I like my DJI fpv ¯\_(ツ)_/¯ I want to fly, not learn about batteries- I also bought a cinewhoop so i am slowly learning about charging lipos through videos like this, but it still scares me, a lot, and I wish that there was just a smarter way to charge them without an absolute mess of cables- with the DJI it's simple, wall plug with 3 outputs, leave them charging overnight, no fear of them exploding, no fear about leaving them charged for a few days if I cant get out to fly, with the lipos it's a power supply, a charger, a balance charging board, a fire proof box, I have to discharge them if I dont use them- the DJI batteries are expensive as hell though
Does it matter that the left two xt60s have balance leads connected different from the four right XT60s? looks like the 1st XT60 from the right has the balance lead going to the left of the xt60 plug and the 2nd xt60 from the right has the balance lead going to the left of the parallel board.
Hi, can you parallel charge with the batteries while connected in series? Maybe a stupid question but! I plan on parallel charging 4x 5s packs while they are connected in series so technically its a 20s battery, I've already made a harness with both parallel and series connections, would it be possible?
So I'm planning on making a battery bank between 200 to 400 batteries. Since they will be in a be already connected they should maintain the same voltage. (of course I would balance them before hooking them all together) why can't I just charge them as one battery instead of individually? I only ask since as a group the batteries should maintain a constant voltage. BTW I want to try and maintain the group (12v) while using an inverter to supply power to working devices. Would I still use the puny charger, thanks in advance.
Any cells that are in parallel do not need to be balanced separately from each other. When you wire cells in serial to get increased voltage, that is when you need to balance. Presumably you will want the output voltage of your bank to be higher than 3.8 volts, in which case you will have some serial sub-banks, which will need to be balanced.
I don't think differing internal resistances are going to affect the current flowing into each pack. The difference is dominated by the voltage drop across the charge board itself, ie the first battery in the string sees a higher voltage from the charger than the last in the string. You can test this easily with your multimeter on the back of the board. I parallel charge using a 10-way board with fuses on each battery. The most dangerous thing I can think of is actually one of the balance leads being disconnected in some way. Ie a wire is broken or a trace on the board is broken. Normally when you balance charge a single pack the charger can see the voltage of all the cells in your pack and detect a problem. If one of your packs in a parallel board has a bad cell and the charger cant see it because of a broken connection you have a chance of fire. You could be getting up to 16.8V and 5 of the batteries have 4.2V on each cell, but the broken pack has 3.7V on one cell and more than 4.3 on the others.
+Goat p.s. I am going to make another round of my parallel charge boards, I will send you one for free if you like. It will be fused on all xt-60 and also the balance ports.
+1...the first battery closest to the source is getting the most current, the last the least and the ones in the middle varying from high to low from closest to the input side of the board to furtherest, and Josh's video actually shows exactly that.
+Goat oh and here's something else I see often that seems to be people are confused about. But if I read my charger manual correctly charge current is only supplied via the main power wires and the balance leads DISCHARGE high cells in order to balance. So if I read right No charging is done through the balance leads..
+Goat That's interesting. I assumed it was the IR of the batteries, but I just did some tests of my batteries' IR's and found they were not that far off. I'm surprised there is that much voltage difference between the front and the back of the board. Is there really that much resistance in the copper traces? I guess a simple multimeter check will tell the tale.
+Goat I just realized that I am in the middle of charging 3 batteries on a 6-way parallel board. I measured voltage at all three of the un-used XT-60 ports, as well as all six of the 3S balance ports (this is a 4S charge). Voltage was identical across all of them. I don't think that voltage drop from the front to the back of the board is the cause.
After a day of flying all my packs are more than 0.1V difference from each other, sometimes by a lot. What's the best practice / procedure then? Just charge them individually, or discharge them all then parallel charge them all together? I find myself not able to parallel charge all that often because my packs are always different.
I actually do have OSD on my rig and I try to land when I see my min voltage flash on my screen, but after the pack rests it ends up being different from my other used packs. I'm also a newbie to the hobby, so I'm all over the place and so maybe when I'm getting low I just need to just hover and wait to see what voltage sits at before i decide to land or continue. Besides that though, thoughts on discharging before parallel charging? Not worth the trouble?
Remember that you want a tolerance of 0.1 volts *per cell*. So for a 4S battery, that's a 0.4v difference. Say battery A is at 14.8 and battery B is at 15.2, you would be ok to put both of them on the balance charger together. I personally try to keep it to a 0.2v tolerance for my 4S batteries, but you wouldn't do any direct damage and risk hurting anything if your batteries were like the ones in my example. One of the most important things to do while you're starting out is to make a correlation between the voltage level on your OSD while in flight and your voltage level after you land and disarm. For my setup, I know that if I'm at 14.8v while doing nothing but hovering for a few seconds, my voltage will bounce back up to about 15.1 once I land and disarm. I only fly my batteries down to 15.0 - 15.2 volts (3.75 - 3.8v/cell). If you wanted to, you could even land and disarm, like you mentioned, and check the voltage while resting. That's totally cool. The more you fly and focus on your voltage in air and on the ground after the flight, the more you'll make that correlation. But it's important to make that correlation early on.
Thats my recommendation as well, .05 to .1v per cell is a safe range, .2 would be pushing it and .3 needs to be charged by its self for sure. this is a very good post and accurate, if I would have read it then it would have saved me from having to write more less the same thing. I did answer a question about why IR makes packs accept different current levels while para charging so I guess it wasnt a waste of time.
so this video gave me a little idea, not sure how "safe" it is but thought i would put it out there as i did it tonight. i had some batteries i flew today and one was just a tad out of range 0.4 on a 3S from the others. i hooked them all up to the balance board and let them sit for about 10 minutes.... went back and checked their voltages and all were dead on at 11.08, so i then proceeded to balance change them all in parallel. thoughts? seems like a reasonable workaround if some are just out of bounds of the safe parallel charge variances...
The 0.1 per cell guideline is specifically intended to keep that initial equalization current to a safe level. The problem happens when you plug the packs in, not when you hit the button to start the cycle.
My charger (I'm sure like most) has a few modes to pick from quick, normal, balance, and discharge. I don't have a lot of batteries yet so I am only charging one at a time. Should I always use the balanced option? Do I lose battery life by choosing normal mode?
The real question is not whether or not you parallel charge multiple Li-Po batteries with different voltage level or internal resistance. They'll simply reduce charge cycle life as you push harder. A MIT study found that parallel charging batteries with 20% difference in their internal resistance can reduce the battery life as much as 40%. As for safety, it's all about whether or not you're constantly monitoring individual batteries for a defect. A defect battery causes heat and heat can start a fire. So as the shorted battery. This is true when you charge multiple Li-Po batteries in series as well. When it comes to charging Li-xx batteries, it really is not electronics anymore. It's a chemistry.
It is true that all batteries slightly differ in internal resistance. But the real reason why each of the batteries was accepting a different amperage is due to the parallel board. The battery closest to the charger will have a higher amperage. But the battery furthest from the charger will get a lower amperage. Better put, if using Direct current to make a light work current drops the longer the wires. Get shorter wires to minimize current loss. To get a true even charge, one of the main power leads should be on the other end of the balance board. This forces the current through all the batteries thus resulting in a even current across all batteries. I know this from Electrathon racing over the years. Iota DLS chargers cover this very topic for lead acid batteries in a PDF online. They go into more detail to get a "perfectly balanced batteries" with a modified wiring setup. But in the end, the same can be applied to really any battery. Nice video Joshua Bardwell, like the videos! www.iotaengineering.com/pplib/balancedcharging.pdf The link to the PDF I mentioned.
Yeah, internal resistance does make a difference. But coming from experience the Iota charging schematic does help to keep all batteries charging evenly.
Battery internal resistance is significant but so is the resistance of the leads and connectors which can easily be comparable to the cell resistance. This becomes more problematic as the charge current increases because the voltage drop across the connectors and leads increases too
Hi, thanks for the great videos. I have a kind of on topic question. I will be putting 3x4s batteries in series to create a 12s pack for an ebike. Could I then put the 3 batteries balance leads in parallel to have one battery checker monitor all 3 batteries? All 3 batteries are the same (graphene 10000mah 4s). This is solely for discharging the batteries on the bike and each battery would be charged individually and not in this configuration. Thanks for any feedback.
If you wire the main discharge leads in serial and then you wire the balance leads in parallel, I think bad things will happen. Think about it: the high and the low balance wire are connected to the discharge leads. So you'll have the batteries in serial and parallel at the same time and ... IDK who will win but I don't like it. I suspect you will have runaway current flow. Draw a circuit diagram and see for yourself.
how does that checker work, is that .007 at the end the difference between the 4 cells within your battery? Also before you charged, you checked voltage. I seen people say that all batteries need to be within .1 volt of each other, others say they only measure the first cell, but I noticed at the beginning you check the voltage between cells as well, does that matter?
All of the cells will be in parallel with their partner in the other packs. So they will exchange current in proportion to their voltage difference. Therefore, all of cell #1 in all of the packs needs to be within 0.1v of each other. And cell #2 with themselves. And so on. In general, if the pack is reasonably healthy, the cells will be close enough to each other that checking only the overall pack voltage will be sufficient. So two 4S packs would have to be within 0.4 volts of each other. But if you have a bad cell, it can be very far out from the others in the pack, and it will destroy all of the other cells it's in parallel with if you plug it into a parallel board. So let's say we have five packs, and they all have cell #1, 2, 3, 4 at 3.6 volts exactly. But one of them has cell #2 at 3.2 volts. We check the voltage of the packs and they measure 14.4 volts. Except for the bad pack, which measures 14.0 volts. Fine no problem, it's within 0.4 volts of the others, right? No. Cell #2 on the bad pack is going to suck current out of cell #2 on the other three. Cell #2 will take damage from the excessive incoming current. And the other cells may be damaged by being pulled down to a low voltage.
Hey man! Let me give you an idea for next video. Recently I've noticed that I can balance discharge batteries with the paralel board it takes a couple of minutes just to balance all packs together. After I can safely charge all the batteries together without issues. There is no information in youtube about parallel discharge at all.
Real world question for you. Balance charge current. If a charger can balance charge at .5a is that faster or slower to complete a charge than a charger that can balance charge at 1.5a? What is the fastest charger in the balance portion of the charge?
The faster balance charge current can make a HUGE difference in the overall charge time. As soon as one cell hits 4.2 volts then the balance current limits how fast the remaining cells can charge.
@@JoshuaBardwell fantastic thank you so much!!! I'm sure a lot of people might want to know that bit of info. Would love to hear a full explanation as to how some chargers can seem identical but one completes charge faster due to balance current.
@@JoshuaBardwell I have noticed that there is no good way to search for a charger that has a higher balance current. would it be to much to ask if you have a list or an idea as to what chargers have higher balance currents?
Thank you again for this helpful video! I have a question : What do you select in the charger? Like if there are 6x Lipo 9A ? (6 times 1500 mha) or 1,5A and treated like it is 1 ? I hope it make sense what I just said :) Thank you!
You mentioned that the charge rate differs over the batteries, because of the internal resistance. Does this mean that some batteries are at the max capacity sooner than the others? If so is not a risk of overcharging?
All batteries are a equal voltage because they are in parallel. There is no risk of overcharging as long as all balance leads are connected. The only difference is how much current is going into the batteries.
The charger pushes charge into the XT60. For balancing, it pulls charge out of the balance plug. Most chargers can't charge via the balance leads alone.
Come on man! Balance lead should be connected first, weaker cables can act as a fuse in case it is one of those days when everyhing cathing fire. Better lose balance cables, than entire lipo blowing up in your face, since XT60 can take enough current to make that a very possible outcome.
@@mikelujanable when parallel charging don't plug balance cables in first. plug main discharge cable (XT 60) first, so when there is a voltage difference it will equalize over the main cable. balance leads are not rated for a lot off current. I am using the same parallel board, the fuse is there for protection and it is only on the main leads (xt60). The balance connector doesn't have fuses. when you connect two batteries with a different voltage for example by accident the fuse will pop and you most likely safe your lipo's. when you connect the balance leads first, the fullest cell will push as much current as needed to lowest cell to equalize. if the difference is to much this will go with a lot of amperage and the balance leads will melt and possibly catch fire. the main leads can handle a lot more amperage and wont melt that fast and the fuse will pop before cables will melt. So XT60 first peeps!?
@@SkywalkFPV Ah man now I am flip flopping. Well I have the flip flopper in chief to thank for showing me thats okay. I find it mostly not an issue as my use in solar requires me to have them pretty much identical voltages I will be plugging the xt60 in first. BTW I am using li-ion so maybe not quite as volatile. Whats a good way to drain an old laptop lipo I got a slightly puffed one I just replaced.
=) Good to hear from you sir! The easiest way for that laptop battery was probably to run it dry before the replacement. I recommend you bring the dead one to the battery disposal if you can (don`t keep it). Always be aware when handling electronic components. Note that I would not try this with a already puffed battery! However a good way for discharging 'draining' an old battery, is checking if there is a visible + and - on it. If you have a flow meter, they usually come with an build in resistance that allows for discharging. Make sure u ground this device and use high enough resistance (needs math), because this kind of laptop batteries need a long discharge time. I can not be held responsible for my input ;) Take care, see u around..
Yee. You were charging at ~10A and that's why that cell was receiving 2.2A. If the charge rate were set at 1c it wouldn't be that high, correct? I'm waiting on my ClampMeter to verify and learn some more about that.
I have 1 question, how do you know which balance port should pair to which xt60 port on parallel board, sine the parallel does not point it out. Or it does not matter, the board will working fine while xt60 and balance port plugged in??
What charger was that? I'm looking for something under 100$ that can parallel 6-8 4s 1000-1300 lipos. I saw your other video about chargers but didn't fully understand it.
+giovanni mercado 8 * 1300 mAh = 10,400 mA for 1C charge rate, or 10.4 amps. To charge 8x 1300 LiPo at 1C rate, you need to put out 10.4 amps. To charge at 2C you need 20.8 amps. Let's say that you need about a 20 amp charge rate or less. 20 amps * 16.8 volts = 336 watts. In reality, your watt output will always be less than this, as the charging slows down as the batteries approach full charge. So it looks like you are looking for a charger in about the 300-350 watt range, rated for about 20 amps. From there, you can make your own decision as to which one best fits your needs.
Without the clamp meter, do you know any way to be sure to not overcharge (more than 2c or even more than 1c) a battery? Any similar rule can be adopted on the internal resistance difference between packs?
+Ryan Hackney Those are 4 mm bullets. I think some people even use 5.5 mm bullets. I would just look at the amp handling capability of the connector. Everything beyond that is personal preference.
+Joshua Bardwell Awesome thanks! Ya, I'm putting in a order now at HK, they have some 4mm bullets that say they can handle 100 amps continuous so should be plenty. They've got the Reaktor 1000W for $70 so I don't think I can pass that up. Did you ever hear anything about a firmware update for LiHVs?
Ryan Hackney No dice on the firmware update. One approach would be to charge the HV's to 4.20 volts on a regular charger and then use a smaller charger to finish them off to 4.35.
+Joshua Bardwell Could you try plugging in cells with certain V diffrence (0.5v?). The current is only limited by the resistance then I=U/R (estimated I know this is an advanced circuit) 0.5V/4ohm (worst case www.rcgroups.com/forums/showthread.php?t=1578001&page=5) would be .125A Nothing special, buth with supercaps and verry low internal resistance It would be problimatic
Do we have to wait until all the batteries are balance against each other before starting to charge (Equalization current ≈ 0)? And I hope you will make an experiment on 2C charging soon :) Thanks in advance
@ Joshua...I would like to begin using a parallel charging board....so please help a non-electronics literate person understand something....say my just flown 3S LiPo battery pack A is at a total voltage of 11.2 v and cell 1=3.80 cell 2 = 3.78 cell 3 = 3.70 what numbers / voltages would be acceptable for other 3S batteries to charge along with battery A ?.... I'am I looking at individual cell voltages or just other battery's total voltage ?......please give me an example with numbers ....thanks
+Gary Vale in your example, I would want to be within 0.1 volts if each cell. So basically every other battery would have to be between 3.7 to 3.8 volts.
Hello, How do you end up with all the batteries almost at the same voltage when you use them? Are you flying the battery based on time, mAh or voltage?
+kitesurfjerry I have an OSD that lets me monitor both voltage and mAh while in flight. If the batteries are all healthy, then running the same mAh results in about the same voltage at the end of the flight. If a battery is unhealthy, it will hit the voltage alert level before the mAh are consumed, and I will stop flying then.
Joshua Bardwell so, if i have a healthy 4s 1300mAh is safe to use about 1000mAh? I also have an OSD but the voltage jumps up and down constantly and is hard to judge the voltage.
kitesurfjerry I use 80% mAh as a guideline, so around 1000 to 1100 of a 1300. But I also watch the voltage, and if I start to see sags below 14.0, I get conservative, and around 13.7 is my absolute bottom.
Do the discharge levels matter? I mean could i put 3 batteries that are partially discharged as well as one other battery that is almost fully charged and will it not overcharge it since the others are discharged further?
No you cannot do that. The fully charged one will discharge into the discharged ones, creating dangerous current flow, and possibly burning out wires or damaging the batteries.
I am looking for a charger capable of charging at least 4 pcs 1500mAh 4S batteries. In that case I need charger to output 4 x 1.5A x 16.8V = 100.8W is this correct?
Doesn't make it safe even if it can be done without damaging the pack. If the pack is already damaged in some way, a 5C charge is much more likely to make it blow up.
why are they all 16.7v isn't a full pack 16.8.. I notice when I change a set they all come out 16.7 but when I start the charger again after just finishing at 16.7 usually it starts charging for ruffly another min or 2 and then they all register 16.8 so why is that?
That last fraction of a volt doesn't make a difference. Don't worry too much about it. What is happening is, the charger is holding the voltage at 4.2 volts to charge each cell up, but as soon as the charger stops charging, the cells "relax" a tiny bit and go back down to 4.19 or 4.18. Perhaps a different charger would do a better job of getting them to exactly 4.2, but if yours doesn't, don't worry.
The only charger I have ever had (And all my chargers are high end chargers) to balance to exactly 4.20 is my Icharger 410Duo, my Icharger 406Duo will bal them to 4.19v per cell and every other charger I have ever had will do 4.18 or 4.19v per cell.. It was odd to see them dead on 4.20 every charge when I first got that charger... and no one I dont care how good you are will notice 1/100th or 2/100th a volt worth of power lol so its moot point. charger applies load and the voltage comes up, it keeps the cells at 4.20v under current and as soon as the current stops the cells relax and the voltage falls 1 or 2 100ths a volt, how the Icharger 410duo does it and does it stupid quickly for that matter and doesnt over charge the cell I have no idea.
I have a small single 50w lipo balance charger that goes up to 6s very similar to the Turnigy 50w ac dc charger. Will a parallel board also work with those.. or do you need a super high end charger to do this..
+Dirk Behrens sure. It takes longer to charge five batteries than 1. If you can charge five times as fast then that's different but your charger can't.
+Kevin Keane I'm not going to make that video. That mod is simple to do, but it is easy to make a mistake that creates an unsafe condition without realizing it. I don't want to be responsible for leaving out an important detail, or having somebody mess up the mod, and somebody getting hurt or worse. The gist of the issue is that you need to isolate the DC negative terminal from earth ground. This will allow the "high side" PSU to get its negative reference from the positive (12v) output of the "low side" PSU. The exact steps to do this depend on which PSU you have. And if your mod fails, the best-case thing that will happen is that you may burn out your PSU. But in the worst case, you can end up with 120v or 220v line voltage, rectified to DC, on the DC positive output rail. This is why I won't do a simple how-to. If somebody is going to do this mod, they need to have thoroughly researched it and understand all the ins and outs. Blindly following steps without understanding of the risks is dangerous.
I have just built 4 x 2s 18650 packs (for my fpv goggles) can I charge all at the same in a balance board? I can't seem to find anybody that has done this.
Joshua Bardwell that's what I thought, I'm not at all good with electrics (however this hobby is amazing and teaches sooo much!) Would you use lipo setting or lilo? Not sure what would be best and how to set it up. P.s thank you ever so much for the quick reply :-) Your tutorials and recommendations are second to none in my eyes
I hope this can get to the author of the video. I'm trying to charge a 6 cell nimh battery stick. it is custom so I have no hook up for a balance board or anything like that. since the nimh battery are very temperature oriented to their charge, I want to customize a balance board that works on temperature only.(of course the LiPo battery charger will work with the overall voltage). So I would need six individual temperature sensors and I want them to plug into a lipo battery charger. if that made sense, could you help me out?
I'm not sure how I could help you. I kind of don't know what you're trying to accomplish. A standard battery charger will have a NiMh setting with a temperature based safety cutoff. But you can only plug in one temperature sensor.
So it is a lipro iMax6. It will charge even without the individual voltage and temperatures within the battery pack. It only gets the overall voltage and temperature. But I would like to hook up individual temperature sensors to each individual battery and maybe connect it to a balance board that works with the IMAX 6. That make sense? Basically I want to charge a cell of six batteries in a line with the only connections on other side of the stick. I may be asking the wrong question. If you had to balance a custom stick(row of 6) nimh batteries, how would you do it?
If I could make a custom setup for temperature and voltage on each individual battery, I would like to do that as well. So maybe I could turn a custom stick into one of those little battery packs with the appropriate hook up to the balance board..
@@JoshuaBardwell i ordered Hota D6 pro duo like hobbymate What should be the settings? I am a total beginner and i still wait my stuff to arrive but i want to get as much knowledge as i can before starting. Reallly appreciate your work and i will support you. Thank you for your videos i learned a lot My gear is going to be: Dji googles v2 Patched antenna from iflight crystal with 2 small ones Dji remote 1 Hota d6 pro duo Iflight protek 35 6s with spares Bat-safe box medium Batteries i have not order yet but i am not in a rush i have to do a lot of simulator work :) It will be great to make a video for parallel discharging and storage. Or can you please tell me what should be the settings for six 6s 1300mah 100c batteries? Have a great day :)
nice to know I was right about this. I have always gone ahead and balanced in parallel without issue but this is fantastic info as always. also.. clamp meter = i.imgur.com/qdI9f1E.gif
+Josh “Wicket” Bryson Clamp meter is the only way to measure current, unless you are working with very small current or need very high precision. The limiting factor has always been that they were bloody expensive, but as usual, the Chinese have saved the average person.
zooby dooby wait you can charge 1300mha with a 1500mha and or with a 1350mha and everything will be ok.. I was under the understanding they had to be same or possibility of overcharge happens
So as long as the volts are within couple points of each other and the amps charging is the total amount between all batterys.. it will only fill to what it's capacity is then push rest on to next battery?
