balancer self configurable?

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Aug 10, 2018
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242
Potentially yes but most likely cheaper to get a proper BMS and expand :)
 
sure, but this should be only a extremely cheap burning board (aka balancing)

configurable with Voltage and Balancing current (via resistor? 1/2 in parallel + fan + led etc)

can be 1S to 1000S and is the cheapest thing i've ever found (with few modification)


and yes, BMS is a must, but doesn't need to be able to balance with this
 
Like the idea,

The board will likely share a common -ve line and the battery voltage detection will need the 0V line isolating each pack. So your issue is how to supply the power to each parallel cell set to balance... could use a boost with it but the efficiency and power draw over time might be an issue. Plus, you can't turn that power draw off so the risk of your battery being fully discharged exists if left for a while.. Hmmmmm..
 
emuland-metroman said:
https://it.aliexpress.com/item/1865..._expid=82c7762b-5f96-4ef4-a9ca-9a54c068d8ec-8

i think that can be "modified" to change relay to mosfet or transistor and make a easy 1s passive balancer.

anyone have already make something orthink to make something with it?

only to know before throw few bucks and try myself.


image_ozpzsy.jpg


yuk. i would not use that. (raw connection from grid to battery ... harsh ...)
 
im using in another way.

voltmeter open close relay to discharge 1S with 1/more resistor. only Need external supply over 6v t keep LCD/other things working. It has serial connection so can talk with other things. if work on 1S and then 2S ill try Arduino/PC communication.

btw It has High output too
 
I bought 4 of those overvoltage relays(4 dollar each)and could not get it to work on my 4s battery. I had the same idea, it will work with a 1s though, as long as you have a seperate power supply. Now I use these as overvoltage protection relays, they didnt go to waste. On these the minus of dc input is the same as minus that records the dc inputvoltage. Ialso tried adifferent relay that went up to 99 volts and that one also had the minus (ground) connected together. If the minus groundwas isolated those would be perfect for what you want to do.

If you want something to bleed balance, they sell the babybloc balancer those bleed almost 2 amps and have over/under alarms, they start bleeding at 4.15 volts but the person that sells them will adjust the voltage to what you require, cost 13 dollars per balancer. I decided to use active balancers but for a 4s thats in the 100 dollar range.

I found out on a battery that isn't too much out of balance, if you charge at 2 amps or less you get a very good charge, at higher amps the BMS will always cut out too early. With a battery that has balance issues you need these high amp bleed or activebalancers. The built-in bms balancers at 60ma is useless to keep a batterypack balanced.

babybloc balancer

image_fmdoxy.jpg
 
jonyjoe505 said:
I bought 4 of those overvoltage relays(4 dollar each)and could not get it to work on my 4s battery. I had the same idea, it will work with a 1s though, as long as you have a seperate power supply. Now I use these as overvoltage protection relays, they didnt go to waste. On these the minus of dc input is the same as minus that records the dc inputvoltage. Ialso tried adifferent relay that went up to 99 volts and that one also had the minus (ground) connected together. If the minus groundwas isolated those would be perfect for what you want to do.

If you want something to bleed balance, they sell the babybloc balancer those bleed almost 2 amps and have over/under alarms, they start bleeding at 4.15 volts but the person that sells them will adjust the voltage to what you require, cost 13 dollars per balancer. I decided to use active balancers but for a 4s thats in the 100 dollar range.

I found out on a battery that isn't too much out of balance, if you charge at 2 amps or less you get a very good charge, at higher amps the BMS will always cut out too early. With a battery that has balance issues you need these high amp bleed or activebalancers. The built-in bms balancers at 60ma is useless to keep a batterypack balanced.

babybloc balancer

image_fmdoxy.jpg

so, problem Is that input and Reading section share same ground.? Need to check if There s some way to cut trace and have circuit still working
 
Yes, If they had used an isolated opamp to pass the voltage through it would have worked becuse it would have isolated the battery -ve line from the supply line and the ADC -ve allowing more then one to be used in parallel.

Easy to test, just a basic continuity between the -ve terminals. Would the relay also need to be changed from NO to NC to act as a balancer ?

Something comparable could be made with isolated voltage for the same price or maybe $0.50 extra.
 
emuland-metroman said:
im using in another way.

my apologies. I jumped to conclusions. I didnt even look at the diagram closely. I now get what you are saying ...



so, problem Is that input and Reading section share same ground.? Need to check if There s some way to cut trace and have circuit still working

um, no, it would never be as simple as 'cutting a trace', otherwise, surely the OEM would have done that.

completelycharged gives some good insight, but ...

completelycharged said:
Yes, If they had used an isolated opamp to pass the voltage through it would have worked
[...]
Easy to test, just a basic continuity between the -ve terminals.

Might be a start, but ... a multimeter is a tool that can only answer what it is correctly asked of it ... Im far from convinced this is good way to test for ground loops/issues.

Ground loops might have just become 'my thing' ... hmmmm. (resisting the urge to crossthread here)
 
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