36V system?

I see people using 36V systems for boat/marine, but is it Ill advised for an off-grid cabin? I now have 3, 100ah lifepo4 batteries and if I string them in series, for 36V, I can input more solar. My Victron 150/35 MPPT says it will work with 36V. I know I’d need to find a 36V inverter (and my 12V charger will only work if I disconnect batteries and charge individually in the event of lack of sun). I’d also need a step down 36 to 12or24 for my DC fridge (which runs in 12 or 24). But would there be some reason I’m missing for not setting them up in series for 36V? Thanks for any input!

36V is not a common configuration, difficult to find equipment. My advise would be to go with a 24V system and purchase 1 more battery. Forget the 36V to 24V converter.

An even better choice would be sell all 3) 12V batteries, if possible, and get a 24V 200Ah battery.

BentleyJ said:

36V is not a common configuration, difficult to find equipment. My advise would be to go with a 24V system and purchase 1 more battery. Forget the 36V to 24V converter.

An even better choice would be sell all 3) 12V batteries, if possible, and get a 24V 200Ah battery.

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Thanks. Got a great deal on the batteries —buy one get one free—already have $$$ concerns—but will cost almost as much to parallel in a second CC and wiring keeping the 3 batteries in parallel @ 12 volts, so considering all options.

36 volt is entirely possible, but there really isn't that much stuff that supports it.

All of my stuff right now is currently 36V and although I got a good deal on the batteries and everything, I wished I had done 24V or 48V instead.

If I had saved up the amount of money that I had spent on my current system over time it would have equaled out if I had just waited and purchased everything needed to step up and upgrade to a "normal" 48V setup.

I'd recommend saving up and getting a 4th battery and going with 48V OR still adding a 4th but staying 24V.

Thanks, that sounds like a good plan. For 48V system (or 36) will also need to rethink PV arrays to get higher voltages. Currently it’s designed for 12V —with low volts in.

arniesab said:

Thanks, that sounds like a good plan. For 48V system (or 36) will also need to rethink PV arrays to get higher voltages. Currently it’s designed for 12V —with low volts in.

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No one asked but, please dont think about 4, 12v batteries with 4 charge controllers. That isnt the way this goes

ScrotusGobbleBottom said:

No one asked but, please dont think about 4, 12v batteries with 4 charge controllers. That isnt the way this goes

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Ha! Nope. I currently have 2 PV arrays, one on the roof, and one on the ground (which catches later afternoon sun)--a second CC will help me maximize charging potential. At most, I'd need 2 CCs for my setup at any voltage.

arniesab said:

I see people using 36V systems for boat/marine, but is it Ill advised for an off-grid cabin? I now have 3, 100ah lifepo4 batteries and if I string them in series, for 36V, I can input more solar. My Victron 150/35 MPPT says it will work with 36V. I know I’d need to find a 36V inverter (and my 12V charger will only work if I disconnect batteries and charge individually in the event of lack of sun). I’d also need a step down 36 to 12or24 for my DC fridge (which runs in 12 or 24). But would there be some reason I’m missing for not setting them up in series for 36V? Thanks for any input!

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Having the same 150/35 MPPT as you have, it has been working well for three years. For the DC fridge (two of them), I have a 30 amp converter, purchased on Amazon. It’s doing a great job for not much money. Have a 3000 watt 120 inverter, purchased from Ali Express. It runs the houseboat fine! EG4 charger (my EG4 36v battery died; awaiting refund) is paired with a Wen 2000-watt inverter generator, for wintertime or running the ac when needed. Have two 100ah life4 batteries DIY. Last one has a JK bms, with 2 amp balancer waiting to go on the system. With sun and 600-watt PV, 36v motor ran 22 miles at a slow cruise. I recommend building DIY battery.