On/off Switch on Battery
- Thread starter deeph46
- Start date
Voltron
1 MW
It's really normal that it makes a spark as the capacitors in the controller charge, but if it's eating away at your contacts, then check out resistor circuits for the plug.. There's lots of pre made and homemade solutions.
These are just Google images as examples, so not verifying that circuit works. The yellow plugs with the green marks have built in pre charge resistors.
But still, even minus the spark problem, always having the BMS on can damage a battery from parasitic draw if left not used for a while...
These are just Google images as examples, so not verifying that circuit works. The yellow plugs with the green marks have built in pre charge resistors.
But still, even minus the spark problem, always having the BMS on can damage a battery from parasitic draw if left not used for a while...
Voltron
1 MW
Depending on the design, no, short of physically disconnecting it. Newer smarter ones put themselves to sleep after a while.
if you reverse engineer the fet gate drive for the output fets, then you can put a switch on the gate drive input that disconnects it from the bms's control line, and instead connects it to whcihever voltage that turns off the gate drive, via a small resistor.
it's not typically very complicated, but it may all be covered in goo or resin, etc., so you might have to take that stuff off risking damage to the bms to get to the circuits.
this will work for any bms that uses fets to contorl the discharge port.
you can also put a switch on the charge port fets but it's not usually needed.
it's not typically very complicated, but it may all be covered in goo or resin, etc., so you might have to take that stuff off risking damage to the bms to get to the circuits.
this will work for any bms that uses fets to contorl the discharge port.
you can also put a switch on the charge port fets but it's not usually needed.
I'm using Daly BMS 14S 30A. Indeed it's covered by rubber actually.
I will read the manual again.
Specs says nothing detail about Mosfets and I can't able pry open the sealed rubber because still in warranty. Otherwise I can still open up the battery case when ever I want. So is it enough to just unplug the balancer connector from BMS?
I will read the manual again.
Specs says nothing detail about Mosfets and I can't able pry open the sealed rubber because still in warranty. Otherwise I can still open up the battery case when ever I want. So is it enough to just unplug the balancer connector from BMS?
My preference is to have the balance leads coming to the outside as well as the main power pair.
Sometimes multiples of, so the non-balncing protective BMS can stay hooked up while other monitoring / testing gear, and/or the balancer(s) and/or charger are also doing their thing.
Removing or replacing or upgrading the BMS is a piece of cake without unwrapping the pack.
And obviously isolation switch(es) are also easy to insert wherever you like.
Sometimes multiples of, so the non-balncing protective BMS can stay hooked up while other monitoring / testing gear, and/or the balancer(s) and/or charger are also doing their thing.
Removing or replacing or upgrading the BMS is a piece of cake without unwrapping the pack.
And obviously isolation switch(es) are also easy to insert wherever you like.
the on/off switch discussed in this thread wouldn't be possible with only balance leads; it doesn't disconnect the bms from the main leads of the pack, so if the bms is powered by those, it still drains the pack. it also doesn't disconnect any load (ebike motor controller, etc) from the cells, so any small standby current draw those systems have still drain the pack.john61ct said:
(the idea i posted also doesn't disconnect the bms brain, but it does disconnect the load from the bms so if the bms has leakage current or the load is still on and the bms is in normal discharge mode, it doesn't drain the pack that way).
Voltron
1 MW
Fyi, it's usually only a problem with a battery that doesn't get charged often, say every couple of months, like on a showroom floor, or during winter storage and whatnot.
