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Anders avatar image
Anders asked

Rare 7s LiFePO4 battery modules A123 - Working just fine, but min float voltage is an issue

Some years ago I acquired a number of 7s3p LiFePO4 A123 modules coming from EV battery packs. They are special because of the 7s configuration giving a voltage range for a "48V" battery from 44.5 - 49v. Low but still well within the specification of a Multiplus II 5000W 48v.

These modules have been waiting for a decent BMS solution. I recently discovered https://www.thunderstruck-ev.com/ - They have a BMS solution for these A123 and finally I can set them to work.

They work fine in a 48v solution, but the bottom limitation of the Multiplus for float Voltage is a small issue. 48V is a but to hight.

As I am building this solution now I have not yet connected my Bluesolar MPPT, but as far as I can tell, the MPPT does not have a similar "bottom" float voltage limitation like the Multiplus.

With an increasing number of available ex EV battery modules with potentially "strange" voltage - and people moving away from old fashion lead acid - ....

... are there any plans to widen the settings of these Multiplus voltages allowing for full usage of these strange battery module configurations?



Multiplus-IIvoltagefloat
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2 Answers
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nickdb answered ·

Unfortunately, I don't believe this is just a software limitation. It is a bit of a niche requirement, unlikely to get much traction.

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Anders avatar image
Anders answered ·

With different battery chemistry and second life reuse of EV batteries already being on our doorstep I think that Victron and others has to adapt

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Related Resources

MultiPlus-II Product page 

MultiPlus-II Manual

MultiPlus-II 230V Datasheet 

VE.Bus Error codes

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