I need help in layman's terms.. noob

[Jonny]

I need some help, I just bought 12 cells (3.2v 100ah) I want to set them up at 12v 300ah. I need a bms and to be honest I don't have a clue as to what I'm doing and the more I try to look at information the more confusing it gets. So what I'm trying to do with these batteries is to install them in my van, I don't have much power demand, just a diesel heater and fans basically. Pictures of what I have so far just need to decide on what solar panels to go with but around 300 watts I'm thinking.

 

[John Frum]

Hi @Johnny why did you pick the redarc?
Never heard of a thor inverter which is not a good sign.
Hopefully its decent oem rebadge.
You need 100 amps continuous BMS to satisfy the demands of the inverter.
The commodity BMS's that I'm aware of don't have realistic ratings.
I suggest the Daly brand and derate by 50%.
You could make 3 12 volt batteries each with a 100 amp daly bms and then parallel them.
This would build in fault tolerance so that your system could still operate even in one battery failed.

58.7US $ |12V LiFePO4 BMS 4S 80A 100A 500A Battery Board 18650 Charger PCB BMS For Drill Motor 14.6V standard/Enhance/Balance with fan|Battery Accessories| - AliExpress

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Note that this bms does not have low temperature cutoff.
Is that a requirement?

 

[DASH]

Solar Panels are cheap. If you have the room, I think You would be happy to have 2 solar panels of 300+ watts. At the very least design the system, so You could easily add a solar panel in the future if You wish.

 

[Jonny]

Hi @Johnny why did you pick the redarc?
Never heard of a thor inverter which is not a good sign.
Hopefully its decent oem rebadge.
You need 100 amps continuous BMS to satisfy the demands of the inverter.
The commodity BMS's that I'm aware of don't have realistic ratings.
I suggest the Daly brand and derate by 50%.
You could make 3 12 volt batteries each with a 100 amp daly bms and then parallel them.
This would build in fault tolerance so that your system could still operate even in one battery failed.

58.7US $ |12V LiFePO4 BMS 4S 80A 100A 500A Battery Board 18650 Charger PCB BMS For Drill Motor 14.6V standard/Enhance/Balance with fan|Battery Accessories| - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

Note that this bms does not have low temperature cutoff.
Is that a requirement?

It's a dc to dc charger with solar charging or mppt.
Temperature is something that I probably should have as I live in New England. I wanted to use the chargery bms but looks to be way to complicated for a beginner

 

[Jonny]

Solar Panels are cheap. If you have the room, I think You would be happy to have 2 solar panels of 300+ watts. At the very least design the system, so You could easily add a solar panel in the future if You wish.

3 of these panels would be perfect for mounting on the vans roof and would have 450w

 

[John Frum]

It's a dc to dc charger with solar charging or mppt.
Temperature is something that I probably should have as I live in New England. I wanted to use the chargery bms but looks to be way to complicated for a beginner

Renogy also makes a dc2dc with mppt but only for 12 volts.
Not saying don't use the redarc, just giving alternatives.