[remy_martian]

Ok. Do that. Then pull the plug to go get a pack of cigarettes....what are your cell voltages? Some may not have been charged yet.

There are ways to not dissipate as much power when charge balancing - it costs money.

 

[remy_martian]

^ anyone got a schematic for these? The docs that come with them on how they're applied?

 

[remy_martian]

That part I get, lol

 

[remy_martian]

It's got inductors, so it has to be a switched current source, doesn't it? An analog bleeder would dissipate power in the pass transistor.

 

[remy_martian]

Not much to go on 😭

 

[remy_martian]

Charging has multiple sources on an EV and the batteries need thermal and cell balance management.

The batteries aren't any scarier than a girlfriend making dinner with meat cleaver in her hand.

 

[remy_martian]

I ordered one of the 4S units cricketo linked, above, off eBay.

I verified that the schematic is the one in the attached datasheet, except they use a couple of 10uF in place of the 22uF.

 

[remy_martian]

Was a lot of ctrl-c and ctrl-v on the component placement, lol

Just watch out for the current limit...I didn't get around to measuring the resistor that sets it on the board I have, but it may not balance worth a crap if you're whacking the stack with 30 amps and it's set for a few dozen mA. Those inductors are not very hefty in terms of wire size.

 

[remy_martian]

NFW that inductor will pass 1.2A, imo

The CHIP datasheet claims the chip can do 1.2A...

When I'm back in the "lab", I'll photo the resistor location for you and maybe will try to measure its ohmage (a tribute to "wattage"). Even the resistor is way undersized to do 1.2A, at first glance.

I wasn't going to put more time in it, but I guess I will 🤓

 

[remy_martian]

The resistor reads 51k in circuit (1k reverse polarity, markings 513 are readable in the pic), so the board I have is set for 1.2A* 🧐

*the resistor is not a current sense resistor, but is a setting resistor, which is why it can be so small in size and so high in "ohmage"