Let's talk high AMP BMS reliable choices

[teckersley]

Hi all. Couple of questions here. I have been using the jkBMS in high speed golf cart applications for a while now and the b2a24s20p has been performing very well so I cannot complain.

Recently, I have been asked to make a couple of battery packs that are a bit out of the ordinary and I would like some input from the group:

1) 24S 300A - yes someone is running a high speed motor and believe it or not 37" tires on a golf cart. I am not sure what is going to happen with the JK but i wanted to see if you guys can recommend a reliable BMS that can support 24s and 300A continuous. Wide open current on a regular cart with 23" tires and the same motor/controller is 170-180A.

2) 35s 250-300A - This will be going in a different type of low speed vehicle. It's quite a bit heavier than a golf cart and yes, 115V or so.

Any recommendations on a tested and reliable BMS for either application would be greatly appreciated. I would like to stick with JK and maybe even JBD but neither seem to have the specs I need.

Thanks

 

[Steve_S]

Once you cross the 250A Amp mark, a FET based BMS is NOT SUGGESTED ! You will require a BMS that uses Relays/Contactors which in turn are rated for the correct voltage & amperage handling. Even those rated for 200A, they are not intended for long continuous output as they will shut down due to FET Temps which get really hot !

Common-Port will use 1 Relay to control the Charge & Discharge.
Split-Port will use 2 relays, 1 for Charging & 1 for Discharging.
*NB, once you get past "48V" (60 Volt) the cost of relays increases significantly but Fortunately, thanks to the EV World, there are many good quality ones available at more reasonable prices.
** ALSO be aware that once you get beyond "48V" things generally are more expensive and more "dangerous" as well.

As far as I know, most golf carts are 48V with some 24V which I don't think there are many of. In such cases a replacement LFP can really work a charm, Will just recently reviewed some very amazing drop-in golfcart batteries. If memory serves, I believe that review showed it had a PACE BMS.

LSEV is a bit of a different fish altogether. Boy, I'd love to convert a Kei Truck to EV...
Many variables & options which a smart BMS may be required to handle such as regenerative braking as one example. The BMS' used in LSEV's and up do tend to be more complex yet flexible to handle the various options and therefore cost quite a bit more.

Some examples:

Products catalogue | EMUS BMS

BMS Mini, G1 Control Units,Smartphone Connectivity Modules,Cell Communication Adapters,Cell Modules,Current Sensors,Display

emusbms.com

123electric - Solutions For Green Energy Systems

Professional, easy to use solutions for off and on grid energy storage.

123electric.eu

BMS Battery Management by Batrium

Battery management Lithium BMS BMS Battery Management System Lithium ion battery management LiFePO4 BMS Li-ion BMS Battery Storage Second Life storage Battery ESS Energy Storage System Cumulus Watchmon

www.batrium.com

Orion BMS 2 | Orion Li-Ion Battery Management System

REC BMS – REC Battery Management System

www.rec-bms.com

Hope it helps, Good Luck

 

[teckersley]

Once you cross the 250A Amp mark, a FET based BMS is NOT SUGGESTED ! You will require a BMS that uses Relays/Contactors which in turn are rated for the correct voltage & amperage handling. Even those rated for 200A, they are not intended for long continuous output as they will shut down due to FET Temps which get really hot !

Common-Port will use 1 Relay to control the Charge & Discharge.
Split-Port will use 2 relays, 1 for Charging & 1 for Discharging.
*NB, once you get past "48V" (60 Volt) the cost of relays increases significantly but Fortunately, thanks to the EV World, there are many good quality ones available at more reasonable prices.
** ALSO be aware that once you get beyond "48V" things generally are more expensive and more "dangerous" as well.

As far as I know, most golf carts are 48V with some 24V which I don't think there are many of. In such cases a replacement LFP can really work a charm, Will just recently reviewed some very amazing drop-in golfcart batteries. If memory serves, I believe that review showed it had a PACE BMS.

LSEV is a bit of a different fish altogether. Boy, I'd love to convert a Kei Truck to EV...
Many variables & options which a smart BMS may be required to handle such as regenerative braking as one example. The BMS' used in LSEV's and up do tend to be more complex yet flexible to handle the various options and therefore cost quite a bit more.

Some examples:

Products catalogue | EMUS BMS

BMS Mini, G1 Control Units,Smartphone Connectivity Modules,Cell Communication Adapters,Cell Modules,Current Sensors,Display

emusbms.com

123electric - Solutions For Green Energy Systems

Professional, easy to use solutions for off and on grid energy storage.

123electric.eu

BMS Battery Management by Batrium

Battery management Lithium BMS BMS Battery Management System Lithium ion battery management LiFePO4 BMS Li-ion BMS Battery Storage Second Life storage Battery ESS Energy Storage System Cumulus Watchmon

www.batrium.com

Orion BMS 2 | Orion Li-Ion Battery Management System

REC BMS – REC Battery Management System

www.rec-bms.com

Hope it helps, Good Luck

Thanks for the head start. Appreciate all of your insight.

FYI, we are building 24s 76.8v golf cart packs for use in high speed applications. They are commonplace now. my personal stretch cart recorded 47.4mph max yesterday tooling around the neighborhood. This pic is our creation for a small footprint 24s pack.

 

[Steve_S]

Thanks for the head start. Appreciate all of your insight.

FYI, we are building 24s 76.8v golf cart packs for use in high speed applications. They are commonplace now. my personal stretch cart recorded 47.4mph max yesterday tooling around the neighborhood. This pic is our creation for a small footprint 24s pack.

If you are pushing LFP to its performance edge ie pulling 280A from a 300AH cell you "will" see heat being generated and collectively the cells can indeed get quite hot - up to 50C/122F and possibly more depending on ambient temps which are very relative ! In a high temp region like Nevada or Colorado the cells hitting 122F would not be hard to reach at all... just be aware of it and plan for it too.