question

dgmar-ni avatar image

Using LiFePO4 Battery 12,8V/300Ah for a large battery bank

Hello,

I understand for a 48V system the max number of LiFePO4 Battery 12,8V/300Ah is 20 units (4 series by 5 parallel). For a PV system that requires 220kWh in battery bank can can I use multiple sub battery banks of 20 units?

Lithium Batteryparallel
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2 Answers
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

For a battery bank with such a capacity I wouldn't use Victron batteries, they are too expensive.
The 12,8V 300Ah Victron battery has a price of 880€/kWh(price list + VAT).
A BYD B-Box 13,8 has a price of around 500€/kWh(average price I found quickly with google in German shops).

1 comment
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But if one was set on using Victron batteries, cost be damned, what are the limitations? I have an install where around 100 kWh is desired but a "max array" of 25.6/200 batteries would be 10 batteries at 51.2 kWh. Is this a hard max or a suggested max? Is the limitation on the ve.bus BMS? Can multiple BMS each with 10 batteries be used on the same ve.bus system?
iand avatar image
iand answered ·

If you want a big battery bank, you really should be using batteries designed to be used in such a big bank, including things like cell balancing and monitoring, you can't just put lots in series/parallel and hope that they'll work. For example, the BYD LVL Premium 15.4 is designed and verified for up to 64 batteries (about 1MWh) and also costs a lot less than the Victron batteries.

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