Charging through DC controller

[Ekartftw]

I have a diy electric go kart that uses a lithium battery connected to a 48V DC speed controller like this:

https://imgur.com/a/xpAq0Dd

Unfortunately the speed controller didn’t come with any documentation, but I’m pretty sure it has a battery charger wires/connector like in that picture.

Can I hook up something like this https://www.hyperpowersports.com/products/replacement-48v-lithium-battery-fast-charger-3-pole.html to those wires and safely recharge the lithium battery? Or was that designed just for something like lead acid batteries? There is no display or anything on the DC controller so it seems unsafe — don’t I need some sort of BMS and monitor to recharge the lithium batteries so they don’t overcharge or is that somehow all integrated in the DC controller?

If I shouldn’t recharge via the DC controller, recommended parts to do so? My lithium battery pack is some no name battery pack that I think was designed for scooters and all it had is a positive and negative wire coming from it.

 

[john61ct]

The ability to safely charge through a controller is by no means a standard feature. Perhaps a user savvy in component-level electronics could manage to do so with a lot of support and cooperation with the makers of a controller with that capability, but likely they would also need a language in common.

What led you to believe you could do so?

Controllers generally have nothing to do with regulating the charge process.

Same with BMSs at this low end of the market.

That charger is self sufficient, plugs into the battery directly.

 

[Ekartftw]

What led me to believe that is the picture shows ‘charger port’
Here is another example with more documentation that calls it a battery charger connector https://electricscooterparts.com/hookup/SPD-48500Bwiring.htm

Perhaps these are for lead acid batteries only? Or I’m misunderstanding what they mean by battery charger.

As for connecting the charger direct to the battery. The battery has a positive and negative wire only. The charger has a 3 pin XLR connector. Is there not some other ‘monitoring’ device needed? Or the charger will sense when it is full and not overcharge and cut off?

Thanks

 

[jonyjoe303]

doublecheck your battery pack, it should a have a bms built in. If it doesn't have a bms, it needs to also have a jst balance wire connector. No 48 volt lithium battery pack will only have 2 wires unless it has a bms. Without a bms or someway to monitor the cell voltage it would be unsafe.

If the battery does have a built-in bms, then you can charge it with that 48 volt charger. Those are CC/CV chargers, just what a lithium battery needs. It will only charge to the max voltage of your pack, the closer it gets to full, the less amps it gives your battery. You just got to make sure the connector is the correct one for your battery.

 

[Ekartftw]

Ok great, thanks. Makes sense. I suspect the controller then also is basically a pass through. It makes it easier so you don’t have to disconnect the battery each time to charge.

I’ll double check the battery pack. It’s like all encased in a thin plastic wrap, but good to know that it likely has a built in bms.

 

[john61ct]

Yes a charge port from the controller is most likely just a passthrough, to the same pair as used for discharge.