Switch to cut output power during charging

[Chuckles1]

Just received a em3ev 52V king shark battery. It comes with a bluetooth bms and an app to monitor the battery on android.

I'd like to monitor charging from my living room, but the battery needs to be switched on to do so, which activates output voltage to controller.

I think an on-off switch in the output circuit is needed to isolate the battery from the controller during charging. If that is right, is there a well-proven switch that is small and reliable? Recommendations are welcome if you have a proven product that is available.

My setup uses Anderson powerpole connectors, which are best left alone and not repeatedly plugged/unplugged. This is a rear hub-drive 500W Bafang kit bike from 2020, and I don't recall the controller specs. So I'm looking for an on/off switch to "unplug" battery from controller so I can charge with battery turned on. Ideally it would come with Anderson powerpole connectors so I wouldn't need to do any wire cutting or soldering.

Thanks for any recommendations!

 

[E-HP]

If the controller is switched off, I see no reason for adding a switch. Are you detecting a current flow?

 

[Alex12345]

Just received a em3ev 52V king shark battery. It comes with a bluetooth bms and an app to monitor the battery on android.

I'd like to monitor charging from my living room, but the battery needs to be switched on to do so, which activates output voltage to controller.

I think an on-off switch in the output circuit is needed to isolate the battery from the controller during charging. If that is right, is there a well-proven switch that is small and reliable? Recommendations are welcome if you have a proven product that is available.

My setup uses Anderson powerpole connectors, which are best left alone and not repeatedly plugged/unplugged. This is a rear hub-drive 500W Bafang kit bike from 2020, and I don't recall the controller specs. So I'm looking for an on/off switch to "unplug" battery from controller so I can charge with battery turned on. Ideally it would come with Anderson powerpole connectors so I wouldn't need to do any wire cutting or soldering.

Thanks for any recommendations!

Your kit did not come with a display and/or no ignition connector in the controller? It's always ON whenever the battery is ON? And you're concerned charging the bike with the controller ON?

Why not just remove the battery from the cradle?

If there's a connector in the controller for an ignition switch, in my opinion it's much better to make a switch for that instead of tinkering with the main power line.

There are things like this

https://www.ebay.com/itm/276242061177

But I fear this and similar are low quality and will combust when you ride and pull even less than 30A. Although you can try if your controller is within their power ratings.

Probably better to make your own, either with some high quality switch, or perhaps just with other connector type such as anti spark XT90.

 

[lnanek]

I've seen people use breakers too. Also there's many rotary battery selector switches out there rated high voltage and amps for boats and RVs and the like. Could just rotate one to a position not connected.

But yeah, worth mentioning like others that the ignition pin in the connector for most controllers does carry full battery voltage, but not much current. It's just enough current to activate a buck converter to drop the voltage down to whatever the controller's logic circuits and any accessories use. It doesn't carry the full current used to power the motor. So the switch for the ignition pin can be much smaller. If you don't have a switch for that now, it could just be shorted to on or a loop of wire sticking out that can be cut like some speed limit loops.

 

[TommyCat]

Everyone may have their own reason for it... this is what I used.

A Solid State Relay (SSR) tucked into the back end of a Bottle battery. Works great on my 1000w system with 52-volt battery.
Had it for 8 years with no issues. No contact sparking like a switch or relay contacts may have problems with. Has a nifty On/Off LED lit push switch.
Shown above during testing but eventually mounted it in my cockpit housing.

See the link for details.

1st Build & E-Bike rider-Magic Pie V5 (rear) -Bottle Batt. 52v*11.5ah-Huffy Parkside - Electricbike.com Ebike Forum


Regards,
T.C.