Thumb throttle wiring - HELP needed

[zooz]

HI All,

I bought a kit - http://www.bmsbattery.com/ebike-kits/345-bafang-350watts500watts-bpm-motor-e-bike-kit.html from BMSBattery, which came with a thumb throttle. The kit didn't have any wiring instructions or anything. I managed to figure out pretty much everything apart the battery level indicator lights on the throttle.

The thumb throttle works as expected, but the battery level indicator lights will not work. The throttle came with a 3-way connector as well as a couple loose wires. I just simply connected the 3-way connector to the controller, which made the throttle work, but not the lights.

Do I need to connect those two loose wires to the controller somehow or it just means that the lights on the thumb throttle are faulty? Does anyone have a diagram or some info on the throttle wiring?

Thanks in advance!
- zooz

[rkosiorek]

the battery level meter reads battery level. so i guess it would have to connect to the battery to read the level. the throttle should have a 4th wire. that 4th wire connects to the battery + (red) wire to read the level.

rick

[Rassy]

I would say not to bother. The LEDs are ok for SLA batteries, but even then, when you send your main voltage to the throttle you increase the chances of an internal fault, particularly if the throttle ever gets water in it. The actual throttle just works with 5V from the controller.

Another issue with the LEDs comes up when you increase your batteries to 48V. The LEDs become useless, are super bright, will probably soon burn out, and the chance of a short is increased. Just for the record, many of us started with 36V kits and then upgraded to 48V for better performance.

[DAND214]

If it's working, don't try to fix it.

the battery level indicator is just usless.

Even with SLA's when the light shows it's low, it too late.

Ignore that and get a CA, best piece or instrument you can possiby own.

Dan

[999zip999]

If you have only three wires for the throttle that's all it takes to work. Some have 4 wires with the throtttle connection. The being live hot the seem as battery voltage, but being hot is a posable problem. The guage dosn't work not worth the trouble. Let us know how it works. That's a cheap kit, plus postage. Oh

[zooz]

Thank you all for your answers! Useful info.

I will just leave it as it is at the moment.

[d8veh]

There should be three extra wires. The brown and yellow are for the red switch and the green is for the LEDs. You can us the switch for anything you want, but if you have one of their controllers, you can cut the thin red wire to the battery connector and connect the brown and gree to the controller side and the yellow to the battery side. The switch will then work as a "standby" switch for your controller to cut the power when you want to. You shouldn't leave it like that overnight because there's still a slight battery drain, but OK for several hours. The LED lights will be on when your controller is active (not standby) and show approximate state of charge of your battery if it's a LifePO4 or LiMn (not sure about Lipos). Alternatively, you can connect the green directly to the battery and the LED's will show approximately the charge.

[chisixer6]

I have a similar kit(Yescomusa) with that battery led's. I got the 3 wires for the throttle with the white connectors, there is also 2 separate black connectors (2 wire and 3 wire), I believe these are for the led's and on/off switch. All of this in a black housing with the 3 sets of wire.