Cheap 3s Lithium Solar Charging & Balancing Module 

I think I’ve got a project I want to use it in. Need some sun though!

Turns out there is a 5s version available, but it will be too big, it’s designed for 26650s. Http://store.sure-electronics.com/product/PS-BC12113

@@AdamWelchUK Fingers crossed that the 18650 3S is popular enough for them to consider a 5S then.

If there is 1A of current and you charge a typical laptop pull 18650 (around 2000mAh) then your batteries will be charged in about 2 hours. So, there's perhaps 4 or 5 more hours of sunlight which could charge another 1 or 2 cells in parallel.

Is the charging and the balancing of the cells in series done by the same leads? Or are there balance leads underneath the plastic holders? I also bought one of these units and want to take it apart to hook it up to my 3s4p battery pack to charge. Just didn't know how exactly I would have to connect it to both, charge the battery as well as balance the battery (many balancing chargers have both charge cables AND balance leads). Does that make sense? Thanks for any input.

I have been looking at these and the wondom 5s and 6s. It is maddening how not a single piece of literature mentions what solar actually accepts. They say up to 24v but is that 1w or 100w... its weird. This lineup at 7s and 200-300w of solar would be really cool. I was thinking this 6s one would make a decent way to get several DC-DC converters hooked up together. Some XT60 cables, etc. And the solar part would mostly be as a backup or portable as needed.

Cheers. I think it’s quite a good little module - I think we’ll be seeing it again before long :-)

Have a similar thing in mind. I am using a Pi Zero W for streaming audio stuff. If I can connect that to a class D amp via a usb soundcard and use this module to power it. I can keep it charged during the daytime using a 10 Watt panel and then it will run day and night I guess. Might make it into a versatile power box. I see loads of possibilities, read fun, again.

@@Luke-san I would try and use the Pi to add codecs like Dolby, DSP

I did indeed - like Julian does. :-) I may do that in another video if it throws up anything interesting. Cheers

like mi i don t find it

Try this one... rover.ebay.com/rover/1/710-53481-19255-0/1?icep_ff3=2&pub=5575189419&toolid=10001&campid=5337903455&customid=&icep_item=141225673896&ipn=psmain&icep_vectorid=229508&kwid=902099&mtid=824&kw=lg

Sounds good. Hope it works for you Andy. Cheers

@@AdamWelchUK Thanks Adam. Here's my first attempt with a 20W panel, 3d printing, gps, arduino, 1602 display and two servos to test the maths. It worked, but burnt out the azimuth servo after a jam. Replaced it and still waiting for an opportunity to timelapse a whole 24 hour cycle. twitter.com/ahaveland/status/1073747078621335552 Now making something much more substantial with 3d printed worm drives which will eventually carry 4 or more 100W panels and won't consume any power when static. Early tests are promising, but still have a way to go for the final build and programming. Will let you know how it goes.

That really looks excellent. Well done. Look forward to hearing about your progress Andy.

@@AdamWelchUK It arrived today - plugged in 3 fully charged cells and the VBat output on the board shows 7V, but the cells are at 12.2V. Maybe it needs to see a load before kicking in? This really isn't what I was expecting, but it could drive another usb buck thingy for a pi or arduino which is what I'm really looking for!

My battery output is 2V but someone said it needs a brief input voltage to trigger it...??

Try this one... rover.ebay.com/rover/1/710-53481-19255-0/1?icep_ff3=2&pub=5575189419&toolid=10001&campid=5337903455&customid=&icep_item=141225673896&ipn=psmain&icep_vectorid=229508&kwid=902099&mtid=824&kw=lg

I have not tried it, but according to the CN3722 datasheet the float charge voltage can be set using a potential divider.

@@delboy4711 As long as it only affects charging voltage, that's useful then

Use mains power, as solar panels cannot charge during the night.

The output from the cells is available via the jst connectors and the output connector in the top left marked vbatt+ and vbatt-. The BM3451 provides under voltage protection. www.si-semic.com/upload/1460800283.pdf

THANKS! Just wanted to make sure my garden lights are not going to ruin my 18650s on long dark days/nights. BTW: I love your videos!

Yes you’re right. In all solar applications you maximise your current while you can and clouds and other weather will reduce that input. So the cells aren’t charged in the optimum way. I built a solar charged 7s4p pack and ran it for a year cycling it as much as possible (there’s a series of videos about it) and tested the capacity after a year of use. That might be of interest to you? ru-vid.com/group/PLXyc_wd5sxbhYhAKHVq8SGQ2Sncl1PDDT

@@AdamWelchUK Oh yes thank you, man! I am building maybe a cheap velomobile with 12p4s and am planning to use a honda civic starter 1kw as an assist for 10-20secs. Efficiency maybe 60%, but it's very simple. I will try to keep the current limited, and charge 6s2p greencap 500F supercaps, then give this current together with 18650 to the motor when needed. I am also thinking of regen braking, but am not sure if it's worth it as bicycle does not have so much "sharp" braking periods... And I would need more weight with sepereate generator, so it's not a good idea until I change everything to a 3phase, but that's later. I want to charge my 18650 pack with two PC power supplies, I've tested them via a load resistor, they seem to work giving 5+12+ total 17V, but the current is going down all the time. So, I will try to use a step up/ step down CC/CV boost converter, but did not know if It's necessary. Looks like two psu's are doing quite well, as I need 15,6Amps of charging current. I will check your build, I am sure to find some important information. Thanks again :)

The alternator itself will regulate and shouldn't over charge your battery. While the engine is running and the alternator is keeping a battery well charged the solar charge controller should regulate too and will probably supply only tiny amounts of current to the battery. So both items can be directly connected to the battery, with the solar connecting to the solar input of the charge controller. For vehicles you just need to think about your solar charge controllers common grounding and a vehicles negative earth. You can use positive or negative ground charge controllers, you just need to think about your wiring. Does that help?

@@AdamWelchUK Sort of, I guess what I'm asking is if there is a solar controller that also boosts the alternator input as it's usually low for a deep cycle sealed battery (from what I understand), especially at the end of a length of wire. I'd like a smart charger that will ensure a proper charge from the alternator, and hoping to find something like the CTEK D250SA charger, but in a less expensive form factor. I've considered just buying one of these as the source should be high enough for the solar controller to boost the 13.? To 14.4v.

Dell and HP chargers need a 3rd connection to "trigger" them. The connector is a pin, and a double-sided barrel.

You didn't get a reply because nobody can read a 1000 word sentence with zero punctuation. Furthermore, you answered your own question regarding the AMPS.

I'd get the 20 or 30 amp personally tbh as it allows for expansion and for the panels in case the produce slightly more than spec sometimes

I explained I’d need to double the capacity of each of the cells in series, not just one - and I think it’s taken as read isn’t it that they’d be better off as pairs of a similar capacity?

Ytfp yes yes you can. As long if you have a 3s1p, you can make it a 3s 2p. Or a 3s 3p or so on, the balance charge balances the series. It has nothing to do with the parallel cells. As long as they have similiar capacity and similar voltage when connected- then the cells in parallel will automatically balance between themselves as the current will simply even out. Unless I just misunderstood what you actually meant. This device is rather worthless with many cells because the power is very limited

@@gregfoster6916 You can't balance cells like that. In parallel or not, these are still two separate cells. You will over time burn out your leading or trailing cells and they will fail. There is no point in having a balancing circuit at all if you are doing this. By this logic why not heap them all together and just charge them and bypass this cell balancer and be done with it. The whole purpose is to balance individual cells, doubling the cells like this 17:22 defeats the whole purpose of having it.

ytfp You can watch every video on here on the subject of wiring a BMS for lithium, A 7s BMS will have a black wire for the main negative and then one red balance wire for each set of cells (or for each series). So seven balancing wires. However if each series has 10 cells that are in parallel there will be no extra balancing wires for the other 9 cells in each series. If you did your BMS would have to have 70 balancing wires for a 7s10p 😂 none do, because it’s not needed. When cells are parallel current flows freely between them and evens out. I have never seen a single BMS with balancing wires for all parallel cells; only for each group of cells in the series. It could be one cell per series and one wire per series but if it’s a 7s 100p. You have 7 balancing leads, not 700. Hope it makes sense. Yes if one cell has a catastrophic failure it often takes out some of the other cells in parallel, but the other series groups hopefully will be protected by your BMS. If your building a monster pack like me where I’m aiming for at least 7S1000P, obviously I want to protect my other cells in parallel. The BMS only monitors the 7 series, each series has a thousand batteries. The way we have found from studying what Tesla does is we connect each battery in the parallel group to a fuse wire which then connects to a bus bar for that group/ series. Then that buss bar will be connected to a balancing wire usually the positive side. And it will also be connected to the negative of the next group/series. And that group will be individually fused. And connect to another bus bar and 1 balancing wire on the positive side this is repeated for each series. So if one battery in a group of parallel cells goes bad it burns out the fuse and will not harm my other batteries. You do want to match your cells closely primarily in voltage. It’s dangerous connecting a bunch of markedly uneven cells in parallel, although in my case i would keep burning the fuse if the voltages are not close when connecting. So it’s important to follow that rule. Need more. If you recycle laptop batteries you will see or drill batteries as well. The total number of batteries in a set up can very, but a lot of laptop batteries I have seen are 3s2p (6batteries). Also I have a lot that are 3s3p (9 batteries). The entire battery will have a main negative and a main positive. Then there are 3 series, each battery in the parallel group is connected pos to pos and negative to negative with the other cells that group forming one series group. Then each series is connected to the next series by usually nickel strip going from positive of series 1 to negative of series 2. The series 2 will connect its positive to the negative of series 3. There may be a visible small balancing wire going to the main negative, then there be a balancing wire connected to each series usually the positive, this very clear when you remove the wires. A 3s 3p. Will not have nine individual wires. It will have 1 for each series that is only 3 and maybe one more for the main ground. So usually 3-4 wires. If the main negative and main positive go direct to the BMS then you may only see 2 balancing wires. But again definitely not 9 balancing wires. I have opened hundreds of laptop batteries and 2 50 gallon drums of drill batteries and this has been true 100% of the time. So yes, if voltages match you can. every lithium ion battery i have seen monitors the series of cells but not each parallel cell. All of them. 100%. But man, if you find a BMS that monitors ever single cell in parallel group then great. That would be fine

Adam Welch hey you can hop in anytime, let me know if I’m wrong here.

ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Gs7hVX8Pp9Q.html

Really useful info. Thanks Stuart.

It only balance when full. And when full you have surplus solar energy ;)

There is only surplus if it is not still charging the other cells, also this unit may not be the only unit connected to the solar array.

@@TheDefpom I personally do not recommend to have more than 1 "mppt" unit hooked to one panel system. Though can be discussed :P I would consider the bank to be fully charged when reaching 4.15V since the current rather fast will start to drop down. And if you have very uneven cells you do have charging to do left on other cells but in most cases that doesnt happen that often. Doing individual charging is generally more costly than just balancing the bank one time and let it have its tall. With my 100kWh solar bank its rare that I dont have excess energy when I start to do the top balancing. And the times that doesnt happen i have an issue with the bank. I hear you though!

@@DIYTechRepairs agree with you. also most diy'ers do not understand that when the battery is full, it doesn't matter how you waste it. i mean the battery is full. was in comment section the other day with a bloke that reckons bypass bms are bad because you are wasting energy that could be fed into the grid. after doing some research and calculations, this would come to about 5$ US per year.

Sorry - new camera. I hope to have it trained soon. :-)