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duclos-laurent asked

Multiplus 2 & Lifepo4 - BMS recommendation

Hello to all,

I'm here to have a recommendation about a BMS for a 14,5kW LifePo4 powerwall.
My actual configuration :

12 x 300WC solar panel wired on 3 x 1200W micro inverter -> power go to my house

House also wired to the grid

I want to add a Multiplus 2 with 16S LifePo4 in order to store photovoltaic power and increase the self consuption rate.

I plan to plug the Multiplus 2 as following.

Can you recommend to me a BMS which can communicate with the Multiplus 2 in order to stop the charge when batteries are full?

Multiplus-II
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2 Answers
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marekp answered ·

For this application I would invest a bit more and install EasySolar-II, if 3000VA is enough for your house.

EasySolar-II has GX and a MPPT for DC coupled panels.

You would need DC coupled panels, because if your battery is flat in the morning and there is no grid the system will not function.

As for BMS, you can use any that has "battery full" and "battery empty"outputs.

Those outputs can be connected to the appropriate inputs on MultiPlus or EasySolar to tell the system to stop charging or discharging.

I bought 123smartBMS Gen3 but I cannot tell you how it works because it was DOA and I am waiting for replacement.

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duclos-laurent answered ·

@MarekP, Hello MarekP, thanks for you answer, unfortunatly I already have the micro inverter in place so difficult for me to invest in EasySolar II as the DC/AC conversion is already made by the micro inverter.

The situation flat battery (on morning) + no grid will be a very exceptionnal case as I have maximum 2 or 3 off grid period for maximum 1/2h.

For the BMS, OK I will check if some BMS have "battery full"+ "battery empty" outputs

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marekp avatar image marekp commented ·

No problem, you can always add the MPPT later if you find it useful.

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