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Would you rather?

solarexodus

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Joined
Jul 29, 2022
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2
Hello Everyone!
I am a newbie, getting ready to buy batteries for my RV set up. I have 20 x 100 watt Renogy 12 volt solar panels (expandable to 3000 watts), a Victron 150volt/100A charge controller, and a Victron Multiplus 3000 (2400 watts) 24 volt 2 x 120 (70 A charge rate). I am looking at the EG4 batteries. Why question is:

Which is better?
2 x 12 volt 400 AH battery with a 200 A discharge rate BMS wired in series - so 24 volts of 400 AH & 200A discharge rate
or
2 x 24 volt 200 AH batteries with a 100 A discharge rate BMS wired in parallel - so also 24 volts of 400 AH & 200A discharge rate

Please also tell me why you think it! Thanks in advance :)
 
With a 2400W inverter on a 24V system you only need about 110A of discharge current.

Another important issue is the max charge current. You have a 100A charge controller. Make sure the chosen set of batteries can handle 100A of charge current (in addition to the 110A of discharge current).

The 2 24V batteries have an advantage that if one fails your system can keep going on the other (of course with half the runtime). Two batteries in parallel are easier to keep balanced (though two 12V in series isn't hard with proper initial setup).

With the 2 12V batteries if one fails your whole system is down.

Good luck mounting and wiring 20 solar panels on an RV roof. I do not envy that task. Are you sure you can't use some larger panels? I know it's a game of Tetris up there. Maybe use two charge controllers instead of one large one with two sets of panels. Maybe one set is of larger panels where they can fit and the other is for smaller panels for the tighter spots.
 
Thank you so much for your answer, that is a good thought regarding one battery should fail.

I know, 20 panels is alot, but the Renogy panels fit really nicely, I could probably fit 5- 6 more than that. where I could only fit 3 of the 400 watt panels. I plan on using the unistrut install method.
 
Hello Everyone!
I am a newbie, getting ready to buy batteries for my RV set up. I have 20 x 100 watt Renogy 12 volt solar panels (expandable to 3000 watts), a Victron 150volt/100A charge controller, and a Victron Multiplus 3000 (2400 watts) 24 volt 2 x 120 (70 A charge rate). I am looking at the EG4 batteries. Why question is:

Which is better?
2 x 12 volt 400 AH battery with a 200 A discharge rate BMS wired in series - so 24 volts of 400 AH & 200A discharge rate
or
2 x 24 volt 200 AH batteries with a 100 A discharge rate BMS wired in parallel - so also 24 volts of 400 AH & 200A discharge rate

Please also tell me why you think it! Thanks in advance :)
You may consider another brand of battery. The EG4 batteries have notable problems working with non growatt/EG4/MPP inverters.

There are tons of people, including myself, that have problems that have not been resolved.

Do some research on these forums. There is someone posting every week with problems.

Regardless of which battery you decide on purchasing, you should not wire them in series/parallel.
 
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