BMS and Charger, 2 chevy 48 v pacs

[Huntin4fun]

I've got 2 chevy volt, 48 volt packs that I have hooked up in Parallel. Needing a charger thats programable to cut off at 48 or 49 volts. plus would like to get a BMS to controll the two pac's. Any suggestions

[BBBHC]

Many of us are using a Zeva BMS. If you want to use the CAN with a charger, there is a specific charger you can get for that. I believe it is a TC, but not for sure on that. You can go to their website and you will find the information on it.

There are some folks here recently that have been getting Chargery brand BMSs along with their charger.

I personally went with the Zeva for the BMS, I like the setup a little better, seems to be more compact and there is plenty of folks on here that can offer assistance with wiring and settings. I have a Chargery brand charger, it came with the Nissan Leaf batteries I bought.

[bronsonj]

You'll need a 12S BMS for those 48v packs. As for a charger you can go with a high amperage unit or a lower amperage unit as you don't need to boil the batteries like you did with FLA. A lower amperage unit will just take longer to charge.

I use a 6 amp charger that cuts off at a specific voltage for my 14S pack.
I bought a MEAN WELL ENC-360-48 from Jameco, but I didn't see any charger on their site that had a cutoff voltage near or close enough but below 49.8v.

If you get a decent BMS it can cut off the charger either directly or with an external relay.

You already know this I'm sure, but for anybody else reading this DO NOT USE the factory 48v golf cart charger. It will severely overcharge your 12S (48v nominal, 49.8v max) lithium pack. The cheap Chinese BMS will let your cells charge to 4.2vpc or 4.25vpc, don't use those because they age your pack much more quickly.

[Sergio]

If You have a 2P12S (two 12S packs connected in parallel), You will need 2 BMS, one for each pack.

[Huntin4fun]

Are you using one charger for the two BMS

[Clawyer27]

Originally Posted by Sergio

If You have a 2P12S (two 12S packs connected in parallel), You will need 2 BMS, one for each pack.

Sergio- I was looking at a similar setup, why do you need 2 BMS? Would one ZEVA BMS work, or the chargery 24T?

[Sergio]

If You have two separate strings of cells you cannot use a single BMS.

You could use a single BMS on a 12S2P (a series of 12 groups of 2 cells in parallel).

This comment is specific to pre-assemble packs like the Chevy Volt that cannot be taken apart to reconfigure the cell/module arrangements.

[Clawyer27]

Originally Posted by Sergio

If You have two separate strings of cells you cannot use a single BMS.

You could use a single BMS on a 12S2P (a series of 12 groups of 2 cells in parallel).

This comment is specific to pre-assemble packs like the Chevy Volt that cannot be taken apart to reconfigure the cell/module arrangements.

So something like this can use one BMS, right? https://www.azlithium.com/shopexd.asp?id=208

[Sergio]

Originally Posted by Clawyer27

So something like this can use one BMS, right? https://www.azlithium.com/shopexd.asp?id=208

No, it will require 2 BMS otherwise your 24ga BMS wires would be connecting cells in separate packs together and the voltage differential could get large during discharge due to differences in internal resistance of each cell.

[Clawyer27]

Originally Posted by Sergio

No, it will require 2 BMS otherwise your 24ga BMS wires would be connecting cells in separate packs together and the voltage differential could get large during discharge due to differences in internal resistance of each cell.

Sounds good. Maybe you could offer your thoughts on my thread in All things lithium forum. Almost done acquiring all parts.