What are amp hours for deep cycle batteries? We explain how battery amp hours (ah) are useful when sizing a deep cycle battery. Amp hours are measured at the 20 hour rate. deepcyclebatter...
I keep reading that, while a battery might be a 200 amp hour @ 20 hour rate, it’s “usable” amps is a lot less. Why is that? I don’t understand what the relevance of 200 amps is , if it only has half that in “usable” amps.
That's like buying a full tank of gas but you can only use half of it, so when you get to half a tank you gotta go fill up again. Some genius out there needs to invent a battery that one can use the full potential of a battery, you buy a 200 ah battery, you can use 200 ah from the battery, now that would be lovely.
Making use of the ru-vid.comUgkxcJ22tnHH9l1vjdIdEIG27iOG55P7LXI8 reconditioning plan, I just saved 2 auto batteries from being completely junked. The guides were very simple to follow. I wish I would have found this years ago! You may use the guide to recondition any battery type
Really, in all honesty, I think what most of us want to know is what amp hours mean in practical terms, not technical terms. It's great to know what amp hours mean when purchasing a battery; that's helpful. But what is more helpful is the information I need on a day-to-day basis: "How long can I run my fan, fridge (or whatever) before I drain my battery?" I know that level of detail depends on the load, but that's where specific examples/scenarios are needed. The 400 watt inverter kinda got to this level of practical information, but the video would have been more helpful (practically), if there had been more emphasis on devices/appliances drawing energy from the battery. At least for me, it would have.
12v car batteries for RV's/Fridges/Camping get complicated quickly. I think the complication really comes from spending our entire lives with throwaway DC batteries in remotes and RC cars/drones etc. usually we run them til flat then throw away and replace. With these batteries we want to measure a halfway mark of usage time before we recharge them back again. This changes everything and throws us into a new lexicon of watts/volts/amps and rate of discharge.
When you use lead-acid batteries in an emergency lighting system. a run-time of one hour is required, ergo one reason for the one hour rating. The rating is known as the amp-hour rating not the amps per twenty hour rating. Twenty hours happens to be the point that gives the best economy. Some manufacturers quote their capacities at the 10 hour rating. Some even put a 1 hour and 5 hour rating on their batteries as well as the 10 and 20 hour ratings. If you look at the spec sheet for some batteries, it will have the number of minutes that you can draw the amps of the amp-hour rating to fully discharge the battery. For example a DiaMec DMD12-100 (12V 100AH) SLA battery has the following specs... 20 hour rate (5.15A) = 103AH, 10 hour rate (10A) = 100AH, 5 hour rate (16A) = 80AH, 1 hour rate (63A) = 63AH, And the time in minutes to fully discharge this battery at 100A = 35 minutes approx (from a graph supplied). It is a lot easier to multiply the amp-hour rating by the battery voltage and work your maths in watt hours when using inverters. At this stage you can set the 50% DoD to get more cycles/lifetime from your battery bank. You also have to understand the efficiencies of your system. Good inverters are roughly 85 to 90% efficient and this must be taken into consideration when designing battery operated systems.. To fully charge a completely discharged 100AH lead-acid battery, you will need to put in 130 amp-hours of charge and this figure will vary a little bit depending on the battery construction and plate chemistry. The reason for the extra energy required is that it is an electro-chemical reaction. You have to convert lead sulfate and dilute sulfuric acid to lead and lead oxide and more concentrated sulfuric acid. If you regularly discharge a deep cycle battery below its 50% DoD, you will end up having fewer cycles or shorter battery life. Please note, I stated "regularly". The Panasonic VRLA Battery Handbook has graphs for battery life (number of complete cycles) and DoD. These figures vary with battery type, style and plate design. Complete discharge = 350 cycles or about a year. 60% DoD = 800 cycles 30% DoD = 1600 cycles The less you make a battery work, the longer it will last. It is plate corrosion that kills most batteries, not sulfation. Lead-acid batteries were invented in 1859 and have remained pretty much the same since then. Some companies have tweaked the chemistry a little to get longer shelf life or reduce grid corrosion and make them less susceptible to heat and vibration failures but the heavier the current draw, the shorter the run time. This is Peukert's Law and was discovered shortly after Gaston Planté invented the batteries. Wikipedia has a very good article abut it.
I have a 14 Amp 120 volt corded electric mower. I plan to convert it to cordless using a battery. I have a 150 Watt DC/AC inverter. Will a 12 Volt 35 Amp/hour battery work? I just need to use it for 30 to 45 minutes. Thanks for your help
I could have said... "Yeah, right!" and left it at that but I decided to do the math for you. The electric motor is rated at 2.25 horse power. The motor requires a 2000 watt inverter... 14 X 120 = 1680 watts plus a bit for inrush current. 1680 / 12 = 140 amps (wattage divided by voltage gives current at 12 volts). Now add another tenth of that current for inverter losses... 154 amps for 45 minutes and that would fully deplete the battery and if you do that too often you will have a very short battery life. Deep cycle batteries will tolerate an 80% DOD (depth of discharge) but need to be recharged asap. The trouble with lead acid batteries is that when you draw a lot of current from them, the amp-hour rating or capacity is reduced. It's called Peukert's Law. I looked through my Panasonic VRLA handbook and the closest battery to your requirement is 12volts and 200amp-hours. It weighs 57kGs and will deliver 154 amps for 45 minutes. It's the biggest 12 volt one they make in that style. As you can see... well I hope you do, a system like that isn't really practical. You'd get a good workout pushing it around, mind you. This is why petrol engines are still preferred for things like lawn mowers and they need a six or more horsepower engine to do the same job. You could use a generator to supply the power if you aren't near a power supply but it would need to be about 3000 watts to allow plenty of energy to start the motor. Generators don't have that reserve that most inverters do. You could trade in your mower for one of those latest light-weight 36 volt or higher lithium battery powered lawn mowers. Bosch make a good one... according to Robert Llewellyn on the "fullychargedshow"... ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-p8n6HLjD0XU.html Have a look.
I appreciate your comment you seem to know quite a bit about batteries ... In my experience with invertors and batteries I've found that invertors cut off at ten volts ...the 2 750 watt invertors that I own (by two different manufacturers) both emit an audible alert to let you know that the battery voltage is getting low if one doesn't crank the alternator generator with in a couple of minutes after hearing the alert the invertor will shut down ...it's beyond me why people still post videos saying you one should charge there batteries when the invertors drain them to half capacity ...it simply isn't possible to drain a battery below ten volts with an invertor...when I was building my battery invertor set up (the video is here on RU-vid) I watched a lot of videos and all said the same thing about draining the battery to half capacity... Can you imagine how surprised I was to find out that invertors don't actually drain batteries to half capacity .... After finding this out by experience I quit trusting off grid RU-vidrs etc. And came to realize that most maybe all have never really used there systems enough to know that you'll never drain a batteries to half capacity with an invertor....
That is what I have in my Rpod 179. 4 gc2 6volt batteries in series and parallel with 3 100watt solar panels and a Xantrex HF Freedom 2000watt inverter.
I bought a 100watt solar system to charge my batteries. I have a 750-1500 watt inverter. I want to be able to run a 700watt coffee maker, 700watt toaster and 700 watt microwave but not at the same time. Can I get bye with one high amp battery.? This setup would be for tent camping.
1500 watt inverter / 12v = 125amps to size cable (look up online adding cable length) 700watt microwave / 12v for a few minutes = approx 3 amps (not calculating inefficincy losses) First idea if using lead acid is two 6v golf cart batteries in series = 12v However one 100 watt panel putting out about 5amps not enough alone to recharge batteries from 50% to 100% in one day
No one seems to know on RU-vid that you need 120 volts of power 5X the energy of a 12 volt battery therefore the output of that battery powering a 120 volt device dischargers that battery much quicker but no one seems to know that for some strange reason and their amp calculations for 120 volts is all wrong
Hello i really love the video plese sir if i have a freezer who pull230 watt 3-12w bulb=36w, 1 fan 60w, 1 flat screen tv 48w who make a total of 364watts. I know 500 w inverter should be able to handle the wattage, what size of battery bank i need for this to run them for 6 hours please
230 watts x 6 hours = 1380 wh 12w x3 x6 = 216 wh 60w x 6 = 360wh 48w x 6 = 288 wh total wh is 864wh multiply times days of bad weather (min 2 days) Assuming lowest temp your batteries will see is 40F, use the ALtE solar calculator www.altestore.com/store/calculators/off_grid_calculator/ Enter 12v for your inverter voltage Battery bank voltage is 431 amp hours
@@DeepcyclebatterystoreSanDiego thank u very much for your answer i am electrician i live in the bahamas nassau i want to kbow more about the solar system your video is very useful to me thank u.
What I want to know is can I run my frozen yogurt machine that’s 208 one phase that’s rated for at least 27 amps and max 35 amps and LRA is 81.00 I was told that it needs a 8500 watt generator but they’re too loud so is it possible to run in batteries for about 10 hours a day
Yes it is . but 2 things. running ur machine on 220 will more than half the amps needed . depending on sun / power access / amount u want to fuss with charging you can go solar/ micro wind to 6v batteries run in parallel to 48 volts (cheapest options are usually 6v golf cart batteries) you can also go with like a tesla powerwall (or make ur own with cells which will triple ur capacity for around the same price) theres also companies like bluetti, jackery etc that sell battery packs with MASSIVE amp hours theres on on kickstarter right now i wish i could jump on but its MASSIVE too and costs about 3500 with solar panels . Hope this 2 year old comment maybe still relevant
My man over complicated things with that 20 hour jargin.. Its best to find a battery that list 1Amp hour, most application will not last longer than a few hrs no where close to 20!? ex. 30 amp trolling motor on 60 amp hour battery runs for 1hr. (50%)
The Voltage charts are for at rest or with loads? I've been using a really cheap $100 Excide 115AH deep cycle battery as my starter and house battery for about a year and half. I've taken it down to 11.5v about 50 nights. I am wondering how long it will last. One number that confuses me is Reserve capacity. If my battery is rated 115AH, I presume that means i have about 700WH of usable but have never been able to achieve that. Also If they claim it has a 205 minute reserve capacity @25amp, what does that REALLY mean.. not really (205*12*25)/60 = 1025WH of usable right?? How is it possible that a 12 fridge that is consuming about 40watts took my battery from 12.6v to 12.1v from 9pm to 6am?
oi oi oi, can u pls explain the calculations with examples (using the same numbers u talked about in the vid) typed in the description, as it still sounded confusing as u verbally explained it. Thank YOU in advance.
You can, but they'll only last for 1 or 2 years. If you don't go below 50% they'll last for 3 to 7 years, depending on how often and how close you come to 50%. www.vmaxtanks.com/assets/images/technical%20info%20folder/Cycles%20VS%20Depth%20of%20Discharge.pdf
I'm sure the gentleman in the video knows his stuff... But we have to keep in mind that invertors won't run on anything under ten volts there by making a battery's amp hour rating irrelevant when your battery reaches ten volts the invertor will emit an audible low voltage warning...ignore the warning and you'll soon find yourself without electricity ... Edit literally five seconds after posting my comment the gentleman in the video is talking about discharging a battery to half it's capacity... Let me say it again ...an invertor will not run on anything under 10 volts making it impossible to drain a battery to half capacity using an invertor... I suppose I'm going to have to post a video showing this is true to finally clear this myth up about draining your battery's to half capacity with an invertor...
Thanks for trying, but you threw soooo many numbers at us and used the phrase "... and we know that the number (whatever it is)". But actually we DON'T know these things, so you went right past many of us quickly. You lost me in 2 mins. Sorry, because I'm sure your info is solid, but not easily taught.
Thank you. I didn't know what what that other hour rating was. I never thought about the fact that the faster you drain the battery, the more "inefficient" it becomes.
oh ok thx i get it now i need 6v battery for golf cart to run 400 amp controller i get about 3 hours each so that should go up with 6 batteries should be all day long
Deep Cycle Battery San Diego I am putting a car stereo together, I have a 220 amp alternator, and I am going to be running about 10,000 rms watts, I know I need extra batteries in the rear to power the two amps, but I am unsure of how big and how many amp hours I will need in total, I am more interested in amg deep cycle.
Yeah, very good and understandable. While I view this I gotta realize that the battery is also going to lose about 10 efficiency also because of possible distance of cabling and also heat stress. While these may seem trivial (or not)? The conditions that batteries are tested under and label printing are of the most perfect conditions to boost their usefulness. Thank You for posting critical information here.
amp hours is not the same as amps per hour. and you clearly cannot do math because the hour units cancel out in your formula at 1:57. gross concept error. 👎
So having a 12v, 40 amp hour lead battery, what happens when I connect my 2000 watt, 12 v inverter and want to run a load of 1 kw microwave for 5 mins and 100 watt lights for six hours?
Great video. Question, my battery is 48v 20ah. My controller is 48v 20ah. Manufacturer upgrade from 20ah b/c none in stock. Will this combo work? Heard it could damage battery. I use PAS too when riding. Hope you can help. /Bklyn👑
I don't think a controller is rated using ah do you mean amps? your controller is a 48 volt 20 amp unit so multiply those numbers and you get a 960 watt machine, ok that has nothing to do with matching your battery aside from it needing to match the volts, you can't use a 24 volt battery with a 48 volt controller cause you won't get the most power out of it, and you can't use a 60 volt battery with a 48 volt controller cause you will fry it ie burn it up, you did not tell us what batteries you are using again if lead acid or AGM than you half your 20ah and it's really 10ah usable, so 10ah divided by 20 amps means you can use it for 1/2 an hour, hope that helps.
Thank you for the helpful information. I have a question, though. If you're running something that only draws 200 watts through a 1000 watt inverter, will you be drawing 200 or 1000 watts from the battery? You mentioned the size of the inverter affecting the draw, so I want to make sure I'm using the right inverter with the right appliance. If my 1000 watt inverter is overkill, then maybe I should pick up a smaller one as well. Thanks for any advice you might have. Sorry if it's a dumb question. I'm a total noob.
Not a dumb question I’m in the same boat. Does my 700 watt inverter really run at max if the load is less? I need to reverse engineer this. If my fridg only run at 3a/120v max intermittently I would still use that as my calculation number as my load. Now where do I go from here?
Hi, can someone help me with something? I have a positive and negative wire going to the back of my van. This wire was used to power a wheelchair lift. I gave the lift away and now I have the cut wires. How can I figure out how many amps it can provide? I know hoe to test volts but how do I test those two wires, positive and negative, to know how many watts are coming out? Thank you.
search the make and model of the chair lift from before. I will have data of power needed to operate. Guessing you had at least the needed amps and watts to operate
Can a Battery show full charge on a volt meter , and still be missing the Amps - where it wont do anything to crank over an Engine?? Thanks in advance.
Please help. My espresso machine is 3,000 watts. I want to run my espresso machine using a deep cycle battery. Can I get a 12v 100Ah AGM deep cycle battery and pair it with 4,000 watts inverter? If it's possible and if my calculation is correct will it give me at least 15 hours of power? Thank you sir.
No your calculation is incorrect I wish it was this way it would be cheap to have backup power .... 3kw coffee machine / 12v = 250ah 1-12v 100ah will last 20min max discharge down to 0 since the voltage will drop below 10v very fast good luck if you can make one or 2 coffee....
You do not it is for starting batteries only they are there it you need to start a engine if your starting battery is dead and the is the only battery you have that is charged
If you are using AGM firefly batteries with DOD or around 95% would you still divide by as much as 2 for a margin of safety when calculating Amp hrs and runtime?
Hi I have 2 55ah Duracell 12v agm batteries in my van hooked up together being charged by 700 watts worth of solar on the roof, I am in the market for getting an inverter possibly just a 500 watt 12 volt hookup, my question is what is the total wattage my system currently makes? Would it be (55x2) x 24 volts= 2640 watts? I’m trying to see how long my battery can last before I run out of power, for my off grid set up and want to know if I can even run something like my gaming console (90 watts per hour I think) thanks so much for any feed back
It sounds like you are explaining Ah's for batteries that are not getting charged up by solar/wind or whatever means. Wouldn't the batteries have more Ah's for a 20 hour period if they are being charged daily?
1cleandude Thanks... I guess 55AH would be ok if I don't try to run to much from it.. I'm learning about all this solar stuff, still ain't got the hang of it all... But in time I will.... I hope any way LOL
First , thank you. enjoyed the video. My Question (answering my own) ( correcting me ) is quite simple, if asked. I like to run a Lighting set up max 12 Hr 15W (900 lum)Devide by 12 is under 1A. 105 devide by 1A will give me a 105 hours. on a 210AH battery? If I run twice it will be in half 55 hr ofrun time. the set up all well be 12v no inverter? A deep cell battery is what I should be looking for???
thank you I am getting a Deep cell 210 AH battery. $120 home depot. will be about the size I need. thank you for the correction I changed the LEd to a 25Watt .. If i start to add to the set up a larger batter will be required thanks again for your help. and repy.
You have multiple errors in this video. Those are NOT the ratings of the battery to go down to no charge. Those are to some cutoff voltage such as 1.7V per cell under load for example. It should be marked on the battery. Improper use of DoD. 50% or more DoD is not the same as 50% or more SoC (State of Charge). You used the term DoD when you should have used SoC. More errors are how you describe the series parallel setup.... Way too many errors in this video. Downvoted!
I am so confused by how complicated batterys can get. I thought agm batterys were always sealed and could not have water added? Do flooded and agm batterys both use the same fluid inside of them?
Thanks for the information. A question though. if I have a RV Fridge that pulls 5 amp hours, and two 6 volt batteries rated for 225 amp hours, would the calculation be: (225x2)/2=225/10 hours=22.5 amps draw. this figure seems to say that I would not have a problem boon docking overnight with the fridge running. Is this correct? Thanks.
"..... at the 20 hour rate....". Um, OK, so what are the other rates and how do I compare a batt ery rated at 100 Ah at "the 20 hour rate" with one at the other rate(s)? I am beginning to think technical people enjoy technical-speak and forget we just want to know what we can run and for how long.Then what does that mean in recharge time at "....????? " (what, amps, amphours, watts, ...).
hello. i want to run 2 krk monitors (online its said both are 50watt each) for 6-8 hours off grid. is this possible with deep cycle batteries? how much and which would i need. please help me im stuck in my research
Could I ask a question and it’s a tricky one , I am about to move into a small boat with a plan to use 2 , 110 aph 12 v deep cycle battery’s to power a 40lbs electric trolling motor and on the motor there are 5 settings 1 through to 5 and 3 reverse settings, iv done a little research but I am a beginner with all this , to my knowledge it’s draws at 20w but I’m not sure if that’s per hour ? And I need to achieve atleast 7 hours of travel per day
sup jeff,i was wondering if i could use a 100ah solar battery for my 2000 watt amplifier in my car? the amp does a continuous 2200 watts at 14.4 volts. and i have a 200 amp alternator. Universal UB121000-45978 12v 100AH Deep Cycle AGM Battery.
Deep Cycle Battery San Diego so if you had 100ah(after taking half of rated ah) divided by say 200amps would it still be the same mathematical approach and result in about 30min of supply?? Also I know two 6v can be ran in series but can they be charged safely with a decent size car alternator or does it depend on the batteries in question?
Someone, please help if you may... I have 2x 12V batteries in parallel. they are lead acid. it sais they have 105 Amps at 20 hrs/each. So in parallel does that mean i have 210 Amp hours at 20 hours? I have 100W light bulb, but if i run it off my 700w inverter, with these batteries, i only get 2.5 hrs of run time, as i dont want to go below 12.1V....i turn it off to save the batteries life. Why am i getting only 2.5 hrs of run time? Please help...thanks.
100 watt light bulb running for 24 hours equals 2400 watt hours divided by 12v inverter equals 200 amp hours bu t at 50% dod limit, you would need a 400 amp hour battery bank check your inverter connection to the battery bank, pos on one battery neg on other
Ok one thing i dont understand is why would AH be for the battery down to zero? I dont think thats correct. I thought AH rating already tales into account the safe discharge level. Why wouldnt they, it wouldnt make sense to not apply that already
I think the best take away from this video is right at the beginning where you state that Ah rating depends on the discharge time both of there batteries are rated based on a 20h discharge time. This is so important because some people want to run a 1200W induction cooktop off a battery. At 12 V that will draw 100A!!! The 105Ah rating does not mean you can use the cooktop on full power for an hour. the discharge has to be over 20 hours!!! ... With 85% inverter efficiency the current draw goes up to 120 Amps. The video gets really confusing when you say a 400W inverter at 12V and you have a 6V battery. Later you mention that you need two 6V batteries in series to drive the inverter. I know youtube wants longer videos but please keep them short and sweet.
Jeff I have watched this video a couple of times . My question . If you have a 5000 btu a/c . 110 volt . The a/c is 1800 watt to start and would run at 1500 watts. With a 3000 watt inverter that would 250 amps. You could run the a/c for 3 hours .Am I right .Thank You .
