MSuper X 3200Wh

[jdsr4c]

I have two unused 800Wh battery packs from my old ACMv2. Would it be simple/possible to connect those additional battery packs to an MSX 84v/1600Wh, making it a 84v/3200Wh beast?

[atdlzpae]

Yes, there are two possibilities:
1. Harder - just expand the battery - the additional battery almost certainly doesn't fit inside the shell, so you'd have to make your own shell.
2. Easier - make a backpack battery and charge the wheel while riding (through the charging port).

Do you have any experience in electronics? If not, I strongly advise against doing any modifications.

[jdsr4c]

14 minutes ago, atdlzpae said:

Yes, there are two possibilities:
1. Harder - just expand the battery - the additional battery almost certainly doesn't fit inside the shell, so you'd have to make your own shell.
2. Easier - make a backpack battery and charge the wheel while riding (through the charging port).

Do you have any experience in electronics? If not, I strongly advise against doing any modifications.

I have intermediate level knowledge of electronics and batteries. I do know that I could technically drop these batteries in an MSX and it would work as expected. What I don’t know is how I would connect the additional battery packs to the controller board. I don’t have an MSX to look at and inspect. 

[Planemo]

You wouldnt connect them to the board, you would just parallel them to the existing 800wh packs with decent sized wire and XT60 connectors. I would however use an XT90 on the single final power connection to the board.

Of course, that would be if the additional packs fit, which they wont.

[jdsr4c]

8 hours ago, Planemo said:

You wouldnt connect them to the board, you would just parallel them to the existing 800wh packs with decent sized wire and XT60 connectors. I would however use an XT90 on the single final power connection to the board.

Of course, that would be if the additional packs fit, which they wont.

Okay that makes sense. Thanks for confirming.

[meepmeepmayer]

There are extra thinner balancing(?) cables between the two packs, right? How would that work with 4 packs?

I love the idea! It's just a question of what cables to use to connect the packs.

[atdlzpae]

@meepmeepmayer Every battery pack has an internal balancing circuit. My KS16S worked fine without the third wire. Knowing GotWay, they don't care either.

@jdsr4c Something like this https://www.banggood.com/XT60-Harness-for-2-Packs-in-Parallel-12AWG-Wire-p-1059810.html will work. But before connecting be sure:
1. You connected them in parallel, not in series (you don't want 160V or -160V to the motherboard).
2. You discharged both batteries to within 0.1V. And preferably take a small resistor (10 OHM?) to synchronize them even further. If the voltage difference is too high, you'll destroy the batteries.

Edited November 20, 2020 by atdlzpae

[jdsr4c]

Great advice, thank you. I'll have to keep that in mind. This project doesn't seem worthwhile unless I had an old MSX that I didn't mind chopping up and modifying too.