5A 36V charger, evaluation and modding

[peterjd]

I love that. 3 options in one on a bike you've probably owned for years? Nice.

Just about 50 years. Originally came vacumn packed from a French hypermarket on a big cardboard sheet to home assemble. Various bits replaced or upgraded over the years but the frame and brakes (not adequate!) are original. Did a fair number of miles at home and abroad (without electric assistance) in our heyday. My wife, Judith, has threatened to put it and me in a skip when I 'shuffle off this mortal coil'. And yes she is convinced she will outlive me

 

[saneagle]

That battery wire is too thin. You should use 14g.

 

[WheezyRider]

That battery wire is too thin. You should use 14g.

I assume you mean the ones in this picture?

 

[peterjd]

The wires in that picture immediately go into a terminal block. The main length of connecting wire is a heavy gauge multistrand used in high quality audio systems to connect the speakers. I haven't a micrometer gauge but it is roughly 1.5 mm twisted diameter which I think roughly equates to 14 or 15 swg. Anyway it doesn't seem to reduce the voltage at the front controller enough to cause problems. I tend to hoard wire and recovered components for subsequent use. I would be in even more trouble from my wife if I bought new when I could get rid of something that might do. Peter

 

[WheezyRider]

I've been using the charger for a while now. I'm very happy with it. It seems to have quite good throttling as it approaches maximum voltage (set by me to 41 V). Once it gets to around 40.7 V the current begins to tail off quite rapidly, slowing down the charging rate to a little over an amp and that tails off gradually over time to next to nothing. What is interesting is that the current throttling seems to work better than the 41 V 2A charger I have, which does not reduce current from its maximum rating until about 40.9 V.

I was wrong earlier about the current at which the charging light goes from red to green. It actually seems to be around 400 mA, when there is still a good 15 to 20 W going into the pack.

 

[cyclebuddy]

I was wrong earlier about the current at which the charging light goes from red to green. It actually seems to be around 400 mA, when there is still a good 15 to 20 W going into the pack.

18W (measured) when the LED turns from Red to Green is the same as my two 2A SANS and one 2A TranzX charger: 18W/42V = 0.42A