Battery charging tips for electric bikes


Active Member
Ann - thanks for the guidance. This is what I suspected.

I "used" to keep my little Lipo RC helicopter/car batteries in the garage.... and they would puff up after a few weeks.... which means they are getting unstable.... and basically unsafe to charge/use/store.
I do have a fun way to render my old lipo's safe for disposal... involving punching holes in them and burning them with fuel in a steel bin...... I'm sure this fall in a don't try this at home bucket :)

Ann M.

Oh YeAH! Exactly :) One of my former techs liked flying RC planes and crashed one in the trees in Zilker Park, Austin
(a really sweet green area) and watched the LiPo batteries flash 20 ft+ flames, so yes a modicum of care concerning charging is smart. With that said, you mention poofy batteries, which indicates some form of overcharging was happening anyway, so you might want to consider a simple safe charging station which includes a surge protector and digital timer to prevent overcharging. And of course, you have to be diligent on the temp side.


New Member
I have a tip for ya'all... there is a gizmo you can buy on Amazon called a "WiTenergy Bluetooth Smart Electricity Usage Meter and Timer" (about $35) that has some great battery charging applications. It measures AC voltage, current, wattage, power factor, and frequency, and is programmed by a cell phone via Bluetooth.
With this, you can:
  1. Delay the start of the charging cycle, and/or stop after a set amount of time.
  2. Stop charging when the current tapers to a certain point (if you want to stop short of 100% charge for longer battery life without paying $300 for a Cycle Satiator charger).
  3. Program it to top up your battery prior to your time of departure.
  4. Figure out how much power you need if you are sizing a solar system or buying carbon offsets.
  5. Troubleshoot charging issues like this one I found:
When I plug my bike charger into it and charge my battery, it logs the data in a graph like this:

From the graph I can see that my fan-less charger actually shuts off when it gets hot, so I can see that I could probably shorten my charging times by adding an external fan (I think the charger is designed to do this).

The android app that goes with this gizmo is a little rough around the edges (haven't tried the IOS version), but I am hoping the developers keep adding more features.

Ann M.

Awesome, @Uplink! Can this system be programmed to do a regular maintenance charge, say 1 hr once a week for folks who have their bikes & batteries stored for a while? Would be very handy for customers of mine who like to leave an ebike or scooter at a different spot, but not used on a regular basis.

Brad Allen

New Member
I found that my Sprint charger was getting pretty hot when resting flat on a table on it's rubberized feet. So I tried putting the charger on it's side instead to allow the two biggest surface areas to come in contact with the nearby air. After a few minutes the charger showed up to be running chilly.

36 Volt Electric Bicycle Battery
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Ann M.

Absolutely @Brad Allen , allow more of the surface area to have access to better air circulation and the charger will dissipate heat better thus running cooler. A common issue with chargers, especially those with no internal fan.


Well-Known Member
Keep my charger plugged in and off, in my garage
Then turn the ebike off
Plug charger into bike battery pack
Turn charger on
After its full charged turn charger off, then remove plug from charger.

Over 1500 charge cycles like this.

Will advise anyone who has a cheap charger to buy a good one, with a metal case and built in fan. They last a very long time and run cool