Piggy backing a voltage alarm with a bms?

How do you store and manage your electricity?
Post Reply
Taxman
Groupie
Posts: 31
Joined: Sat, 26 Jun 2010, 23:51
Real Name: squeet

Piggy backing a voltage alarm with a bms?

Post by Taxman » Fri, 09 May 2014, 01:31

Hi guys

I'm working on the battery pack for my motorbike conversion, I've got 64 x a123 pouch cells, 2parallel, 32 series, for a 40Ah, 100v pack. I've got 2 x 16cell BMS modules that are just simple shunt modules like this http://www.ebay.com.au/itm/LiFe-BMS-bat ... 4acc07882c.

My question is - could I put four of these alarm display modules in parallel with the shunt modules? http://www.ebay.com.au/itm/RC-BVM-8S-1- ... 3a8c47a90e

Would they get fried when the bms modules are shunting current? Maybe I could get a bms/display/alarm combo unit.

User avatar
Johny
Senior Member
Posts: 3704
Joined: Mon, 23 Jun 2008, 16:26
Real Name: John Wright
Location: Melbourne
Contact:

Piggy backing a voltage alarm with a bms?

Post by Johny » Fri, 09 May 2014, 15:18

Taxman wrote:My question is - could I put four of these alarm display modules in parallel with the shunt modules?
Would they get fried when the bms modules are shunting current? Maybe I could get a bms/display/alarm combo unit.
No, they wouldn't get fried - it would all work OK.

The only issue I can see is that the display module says for pack voltage of 3 to 24V which doesn't quite jell with the 8 cell LiPo spec.

Pack Voltage Range: 3.3 - 24V
Cell Voltage Range: 0.5 - 5V


It wouldn't hurt to try to clarify that with the seller.

Other than taking up quite a lot of room - dash wise (although it can do remote alarms so the display units don't have to be visible), it looks like a good lowish cost solution.

BTW: EV Power sell a 16 cell BMS which could lower your costs if it can do the current you want.
http://ev-power.com.au/webstore/index.p ... s-30a.html

Taxman
Groupie
Posts: 31
Joined: Sat, 26 Jun 2010, 23:51
Real Name: squeet

Piggy backing a voltage alarm with a bms?

Post by Taxman » Fri, 09 May 2014, 22:43

Cool thanks Johny,

Yeah, I might go for 4 of these guys if I can find one with a lower alarm voltage setting

http://www.ebay.com.au/itm/10x2in1-RC-L ... 3601&rt=nc

It's just that I've already got the BMS units, I was going to try and fit the displays under the rear seat.

cheers

Post Reply