Where do you set your charger while charging? Do you use a timer?

67-LS1

New member
Local time
10:38 AM
Joined
Dec 10, 2024
Messages
21
Location
Walnut Creek, CA
I store my e-bike next to my workbench and I just set the battery charger on the wood top. The battery charger gets pretty warm while charging so I’m wondering about leaving it on wood while it charges.
Does this concern anyone else? Would airflow below the charger help? Maybe set it on a couple of spacers?
Or should it be on the concrete floor?

And does anyone use a timer for charging? I’m using a countdown timer in the outlet that I can set for 1, 2, 4 or 6 hours. I’ve been trying to run my battery down to 25-30% before charging and if I do a 4 hour charge gets it to 85-90%. I just hate to leave it on all the time and I don’t want to have to temper to go back and unplug it.
 
Wood burns. Set it atop a half-thick red brick. They are what... $1 at Home Depot? I do that with my battery dischargers and the resistor that the battery dumps the energy into gets up to around 500 degrees fahrenheit. Scorches the pavement set directly on it, but no issues with the brick in between.

You absolutely don't want to leave a battery on a charger. Too many ways for the charger to fail - in particular I have seen them not stop when they are supposed to and keep on charging.

I wrote up two different articles on using a countdown timer. This is the basic unit that is in wide use by ebikers. A mechanical cutoff timer is simpler and superior to an electronic one. In addition to cutting off for safety, you can use the timer and a little brain power to figure out how many volts per hour your charger adds to your pack and set the timer so you do a roughly 80% charge.


And after others took apart the timer I describe above, and noted its fine for purpose but not up to taking a hit from say an electrical surge, I went to a residential grade timer. I have been using one now for about a year-and-a-half daily, attached to my wire shelving rack in my garage.


And since you are talking about figuring out ways to do a battery discharger, here's how I did that. Same residential grade timer with a lesser duration, plus a resistor designed specifically to drain an ebike battery. Pulls about 7a from a 52v battery which will bring it into line pretty quick. Not something you want to be doing every day because discharging counts towards the total lifespan of your pack.

You could do something much gentler - and slower - with a row of light bulbs with ceramic sockets you wire onto a 2x4.

 
I use a 24-hour mechanical timer and charge the battery in the family room in the evening hours when I am home and can see the charging red light from my chair while watching TV. I estimate how long it will take to charge the battery and add an hour to the timer. I usually catch the green light before the timer ends. I charge to 100% but only when I plan to ride the next day.
 
Back
Top