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diy solar

100ah vs. 200ah

Soggy Man

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Nov 28, 2020
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I'm getting ready to build a van for travel with solar panels and dc/dc charger. Would be better to get 2 100ah batteries or 1 200ah battery. What is the difference other than the case size size.
 
2x 100ah give you some redundancy, single battery is easier to pack. Cost wise I think the 2x batts are a little cheaper usually.

If I had the space I'd lean towards the dual batteries for redundancy. At least then I can still power things while I'm waiting on a new battery to arrive in the mail.
 
If you are considering lithium batteries, then you will also have one or two BMSs. With BMSs you will have to consider their amp ratings/limits and how they behave in parallel with other batteries.
 
I would be inclined to get the 200 Ah to keep it simple. As said above, verify the specifications meet your needs.
 
Depends on what batteries you're buying. If lead acid I would buy two 200 ah or larger 6 volts vs one 12 volt, or two 100 ah 12v batteries. 6 volt lead acid batteries are better suited for deep draws.

If lithium, I'd get two 12v 200 ah batteries for redundancy, but that's just my opinion

Enjoy,

Perry
 
Depends on your max amp draw, most 100 AH batteries have a 100 amp max power draw, when you have 2 in parallel they can provide a max draw of 200 amps, which you may need if you have an 2000 watt inverter, by contrast many 200 AH batteries, hav a BMS with a max amp draw of 100-150 amps, though a few do support 200 amp max power draw, so it all comes down to your needs.
 
Depends on your max amp draw, most 100 AH batteries have a 100 amp max power draw, when you have 2 in parallel they can provide a max draw of 200 amps, which you may need if you have an 2000 watt inverter, by contrast many 200 AH batteries, hav a BMS with a max amp draw of 100-150 amps, though a few do support 200 amp max power draw, so it all comes down to your needs.
Agree with this. I went with a single 200Ah but could not get enough amps out of it to run a 2k inverter. So I had to buy another 200Ah battery. Not the end of the world but expensive.
 
Agree with this. I went with a single 200Ah but could not get enough amps out of it to run a 2k inverter. So I had to buy another 200Ah battery. Not the end of the world but expensive.
A 2K inverter could be pushing the pair of 100s pretty hard. Much better with the pair of 200s.
 
Agree with this. I went with a single 200Ah but could not get enough amps out of it to run a 2k inverter. So I had to buy another 200Ah battery. Not the end of the world but expensive.

What was the battery? I'm hoping to run a sustained 150A for 5-10mins from my 200Ah battery when I get it - am I dreaming?
 
It's imperative that you match the battery max amp potential with the proper inverter. 100amp bms will be ok with a 12v/1000w inverter. That same bms will not at all like having a 1500w inverter hooked to it if you are pulling more than 1000 watts. Remember...AH (amp hours) is not what you need to look at when considering current draw. You need to know the rating of the BMS (100a or 200a).

For this reason I spent more to get a lifepo4 battery with a 200a bms (Power queen 'plus') in order to play well with my 12v/1500w inverter.

Proper gauge wires between your components is crucial as well.
 
go with 1x200ah . easiest to manage. only 4 cells to match and then to monitor. and is cheapper per ah(kwh)
 
It's imperative that you match the battery max amp potential with the proper inverter. 100amp bms will be ok with a 12v/1000w inverter. That same bms will not at all like having a 1500w inverter hooked to it if you are pulling more than 1000 watts. Remember...AH (amp hours) is not what you need to look at when considering current draw. You need to know the rating of the BMS (100a or 200a).

For this reason I spent more to get a lifepo4 battery with a 200a bms (Power queen 'plus') in order to play well with my 12v/1500w inverter.

Proper gauge wires between your components is crucial as well.

I absolutely know this, but I assume everyone else here does as well. So when @corn18 said his 200Ah battery struggled with his 2000W inverter I took that to mean that I can't trust the spec sheets, as I assumed his 200Ah battery would have quoted a 200A max continuous discharge - since most of them do.

Hence me wanting to know which battery had failed him. I guess I can infer from his later post that it was a 206Ah SOK...

...which upon looking it up does actually quote a max continuous discharge of 100A. I'm surprised, since lots of people on here seem to recommend SOK, and that seems to be a weak specification compared to lots of other brands.
 
I have 2 x 12V 206Ah SOK batteries wired in parallel. I have a 3000VA Victron Multi Plus II inverter. With the old non BT BMSs, I have pulled 286 amps for 10 minutes and they worked great. With the new BT BMSs, I can only get 250 amps and they shut down. So a 3000W inverter actually needs 3 SOK batteries if they have the BT BMS.
 
I have 2 x 12V 206Ah SOK batteries wired in parallel. I have a 3000VA Victron Multi Plus II inverter. With the old non BT BMSs, I have pulled 286 amps for 10 minutes and they worked great. With the new BT BMSs, I can only get 250 amps and they shut down. So a 3000W inverter actually needs 3 SOK batteries if they have the BT BMS.
Hi, I'm thinking of getting 3 SOK's 206Ah with a 3K inverter. As per your comment this should work fine, correct? I'd be using 8x100W panels.
 
I'm thinking of getting 3 SOK's 206Ah with a 3K inverter. As per your comment this should work fine, correct?
A 3kW inverter on a 12V system can result in up 300A being pulled from the batteries. Those 3 batteries in parallel can easily provide the 300A. But you will want to fuse each of the 3 batteries.
 
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