Can I use Multiplus(first version) 12/3000/120-50 with 200Ah Lifepo4 battery

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kostya asked Jan 23, '23

Can I use Multiplus(first version) 12/3000/120-50 with 200Ah Lifepo4 battery

So I bought components for a camper year ago, but because of multiple reasons get to installing components only now. And in manual for Multiplus(first version) I discovered that minimum recommended capacity is 400Ah.

Initially the plan was to buy two such batteries but now this is not an option.

1. So is it possible to use it with such battery, or it will damage it or wouldn't be function properly? I think currently loads should be not more then 1000 watts

2. Should I set up inverter settings so it wouldn't be allowing to discharge battery more then recommended amount of Amps(not really sure if such thing exist).

inverter current draw

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Answer 1 · 2023-01-23T19:55:04Z

kevgermany answered · Jan 23, 2023 at 07:55 PM

One thousand W is about 80A at 12V. Ok for short periods, but the battery won't last long if you over do it.

Charge current can be limited by limiting input current to some extent, or if you have a GX device in the system, enable DVCC and that has a charge current limit setting.

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kostya commented · Jan 24, 2023 at 04:02 PM

Yep, I have Cerbo GX. Thank you.

So if I understand right the point of recommended capacity 400-1200Ah because if I use inverter at around 60-90% of load it wouldn't drain battery too fast which could lead to battery damage?

And so as I understand 70mm wire with 200A fuse should be more then enough for my situation(for battery and from bas to multiplus)?

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kevgermany ♦♦ kostya commented · Jan 25, 2023 at 10:39 AM

There are other factors such as inrush current when the inverter is turned on.

Cable size will depend on acceptable voltage drop under load, cable length (add both legs) and whether the cable is open to air cooling or buried in insulation. Some cable current ratings are at 70C or higher...

Check the specs of the battery you intend to use. You may find that 80A is too high a load. In this case the BMS will cut output.

Remember also that if you add batteries to increase capacity later, you will have an unbalanced battery pack. With some LiFePO4 batteries it's ok.

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