Relay/Contactor based BMS for 48v Headway battery, high amperage application

jberger

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Looking for recommendations on a BMS for this high amperage configuration.
I am about to pull the trigger on (2) Headway Superbeast 24v packs from Battery Hookup for a 48v Golf Cart.


Each pack is 24v 8s6p and I'll need to wire them up for 48v to the controller.
These packs are built for high discharge applications and include a contactor on the outputs, pre-wired for BMS and include a large fuse. I'm going to start with 2 and possibly expand to 4 for more run time based on how it performs.
The golf cart has already been upgraded to a Navitas 600a controller, and also has a large solenoid installed for use with the current LCA 48v batteries.
Given that the cart has a solenoid and each pack has a contactor, I'm trying to find a BMS that will play well in this setup, rather than starting over.

Any ideas are appreciated.
 

NVS

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Do you know how many amps your cart pulls now? You'll need to know so you can size your bms correctly. You can get a 350amp shunt amp meter.

AiLi Voltmeter Ammeter Voltage Current Meter Voltmeter Ammeter 100V 350A Caravan RV Motorhome 999 AH https://smile.amazon.com/dp/B07FGFFHC6/ref=cm_sw_r_apan_i_PE72EW068GQP7P4TTW93

I have one of these and it works great.
But if you are pulling more than 350a victron makes a 500amp. But it's over $200.
 

BentleyJ

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Do you know what the coil voltage is on the contactors and solenoid? Holding current? There are BMS products that have aux outputs to drive external contactors but in many cases they are limited on voltage or current or both. Given that your application requires several contactors to all be energized simultaneously I can see where that may be an issue. Its possible that some kind of intermediary automotive relay with a low draw 12V coil and can handle 10 to 15A on the main contacts could be used to drive all the larger contactors. I've developed a couple of PCB controllers to operate latching contactors from a standard NO BMS aux output. Feel free to post more details maybe myself or someone else can help.
 

Ai4px

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Gigavac GV241FAX . Holding current is like 2watts. it'll do 400 amps continuous, 1000 on surge. Better use a precharge contactor.
 

jberger

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Solenoid voltage on the Navitas controller is 48V, not sure on the Headway packs but I'll check them when they arrive.
I plan to do some logging this weekend to determine the amp draw, the course has some large hills so I'm sure it's in the 200-300 range when loaded up.
Thanks for the help, I'll get some numbers and post them up.
 

JPV

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Jun 25, 2022
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Curious what you found during logging… I have a very similar setup (Navitas 5kw/600amp, oversized wheels) and also building a battery.
 

jberger

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I did run some logs with the max draw set to 350 amps in the controller.
It was pulling all 350 on the start of long hills, so it might have pulled more but I didn't want to abuse the lead acid pack since it's nearing replacement.
I forgot to save the logs, so I'll do that again when we are back in town and post up the graphs.
 

Rocketman

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I am using a Batrium BMS - and it would work just fine. - it controls contactors just fine.

But it is a bit expensive. It has lots of cool bells and whistles.
 

BentleyJ

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I am using a Batrium BMS - and it would work just fine. - it controls contactors just fine.

But it is a bit expensive. It has lots of cool bells and whistles.
Batrium doesn't get much attention on this form. It seems to be a good product, though I don't have personal experience with it. I understand it can also produce a 24V pulse for a Remote Trip breaker, for example Midnight Solar. The only thing negative about the Batrium onboard aux relay is it seems to be limited to 30V which means it will not drive a contactor with a 36V or 48V coil.
 

Rossman

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Batrium doesn't get much attention on this form. It seems to be a good product, though I don't have personal experience with it. I understand it can also produce a 24V pulse for a Remote Trip breaker, for example Midnight Solar. The only thing negative about the Batrium onboard aux relay is it seems to be limited to 30V which means it will not drive a contactor with a 36V or 48V coil.
I don't think the Batrium can drive the Midnight Solar trippable breaker? Usually people recommend an ABB SACE TMax breaker but they are wildly expensive.
 

BentleyJ

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I don't think the Batrium can drive the Midnight Solar trippable breaker? Usually people recommend an ABB SACE TMax breaker but they are wildly expensive.
Interesting. I recently had a brief exchange with a forum member who was asking about the PCB control board I designed to provide the necessary 24V pulse for a Midnight Solar Breaker (Carling Tech, Type F) and he had said that the Batrium could be programmed with a 200ms pulse. So now I'm not sure what to think. In a case like this I need to read the Batrium manual myself. Thanks for correcting potentially incorrect information, I hate it when that happens.
 

Rossman

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Interesting. I recently had a brief exchange with a forum member who was asking about the PCB control board I designed to provide the necessary 24V pulse for a Midnight Solar Breaker (Carling Tech, Type F) and he had said that the Batrium could be programmed with a 200ms pulse. So now I'm not sure what to think. In a case like this I need to read the Batrium manual myself. Thanks for correcting potentially incorrect information, I hate it when that happens.
Interesting. Well, to be honest I'm not an authority, but I considered using a Batrium and when looking for alternatives, I found the Midnight solar breaker, but also a post somewhere saying it only works with their equipment.

I could very well be wrong - I guess I would ask Batrium or Midnight solar to get a more definitive answer!!!!!
 

Rocketman

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It’s always the devil in the details…

Batrium does have a setting for a pulse, now will it trip that breaker…

I use the a contactor- EV200AAANA, so I can’t help with that detailed question.

Good Luck!
 
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