question

brette avatar image

3 x 48V victron battery/multiplus in series for electric vehicle?

After completing a few offgrid installations with victron systems and having converted a vehicle to fully electric in the past, i was thinking through the possibly of building another EV using victron components. 3 x 48v systems in series gives 144v and with a 400a discharge limit (200a cont.) via 6 x series 24v 200ah victron batteries - this corresponds to about 57kw peak and 30kw continuous which is within the acceptable output for a small-medium EV.

since victron equipment only works with up to 48v nominal systems, 2 options could exist to use the multiplus & associated components;

1. parallel the 3 x 48v strings with 350A anderson plugs before charging with a single multiplus

2. or have 3 x 48V multiplus running independently but with the connection to shore power paralleled and 240VAC outputs paralleled?


option 1 requires more steps to charge but only requires 1 large capacity multiplus unit

option 2 however may be subject to ground loops since multiplus 1 would see 0V&48V, multiplus 2 - 48V & 96V, multiplus 3 - 96V & 144v. another post on here suggests the multiplus are infact isolation transformers however i can see a few scenarios where where a ground loop could occur (ie when EN relay reverts to the grid). i also assume multiplus outputs couldnt be paralleled as they are designed to do.


i would be interested to hear from a victron engineer on how this could work ? having a dual-use battery pack could make the investment more justifiable.


look forward to any relevant comments!

Multiplus-IILithium Battery
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1 Answer
Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

I guess option 2 should work because each MultiPlus is connected to 48V.

BUT:

This kind of setup is definitely not supported and on your own risk! Therefore you will not get any official advice from Victron.

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