Who wants to take a peak inside the Samsung SDI battery with me? Well come on over!

[Marcusjackson]

Originally Posted by TheCartBoy

When I set the continued current limit to 36 amps, this means anytime I pull more than 36 amps, it goes into the time limited (user adjustable) over current protection. The default is 300 seconds allowed, then it will shut off and has a default 60 seconds cool down.

The allowed over current limit is not adjustable, its the hardware limit of the JK BMS. I purchased an 80 Amp continuous, 150 Amp peak BMS (BD6A17S8P). And during testing, it would appear the peak current limit, 150 Amps, is what would be allowed for 300 seconds.

So I oversized the BMS for this cell pack, and that's not a good thing. A 100 Amp peak BMS would be more suitable for these cells as the datasheet indicated 107.25 Amps peak discharge.

I will be replacing it with a lower rated unit for this reason and more.

Great tear down and info. Thanks for sharing

[DaveTM]

I do all my delicate soldering with the right tools!!

[Adjake]

I go away for a week and a half and I missed all the fun!!

I have a couple of warranty packs that I hope ezgo doesn't want back.


edit didn't realize this was from a few months ago

[Marcusjackson]

If I understand this thread correctly; you are rebuilding the pack with new cells and BMS?!? Why a new BMS? Was the first one bad or because ur using different cells?

How are they holding up since the change?

[TheCartBoy]

Originally Posted by Marcusjackson

If I understand this thread correctly; you are rebuilding the pack with new cells and BMS?!? Why a new BMS? Was the first one bad or because ur using different cells?

How are they holding up since the change?

On this Samsung Gen 1 battery, the 'full' BMS is external and it did fail.

The cell modules here do not have a full BMS, only a cell balancing PCB. I removed that and install a full aftermarket BMS. It does not work in the original golf cart because it lacks the proprietary CAN bus communications, but works fine as just a standard 48v battery.

When I discharge tested the cell module, it was pretty much fully capacity good as new.

[Marcusjackson]

Originally Posted by TheCartBoy

On this Samsung Gen 1 battery, the 'full' BMS is external and it did fail.

The cell modules here do not have a full BMS, only a cell balancing PCB. I removed that and install a full aftermarket BMS. It does not work in the original golf cart because it lacks the proprietary CAN bus communications, but works fine as just a standard 48v battery.

When I discharge tested the cell module, it was pretty much fully capacity good as new.

If the BMS did not fail could you have just “replaced the cells” steps in this process and get the cart working as designed?

[TheCartBoy]

Suppose you could but the way it's manufactured, they are all spot welded to those thin metal sheets, repair is going to be a pain.

[davros]

Any clues as to what failed on the original BMS? not salvageable?