Originally Posted by Doc_Wui

When does the bike die? Does it happen with freshly charged batteries or maybe after 10-12 miles when you have used up half the range?

more like after a couple miles... the first throttle is dead dead... no power to it for some reason and tested continuity in the wires earlier and all wires were good from connector to solder points ... after i put the second (new) throttle on everything was back to normal for that first week as stated

Does it stay dead or does it recover for a little more riding? If it recovers, can you feather the throttle and go on for a while?

Yeah at first it was kind of cutting on and off and if i retwisted it would work... or holding at half or more it would kick on but it was real inconsistent..


Do you have any voltage indicators on that bike?
no legit voltage meters


What I am trying to do here is make sure it's not a voltage sag problem from weak batteries as opposed to a real throttle failure problem.

Your motor kit has no pedal assist, right? It's all throttle. Do you know your cruising speed? front hub yes, about 15ish mph

I have some experience with those same batteries. I run them separately on a little 36V motor. Put two in parallel for my 500W motor. They're about 4AH each when pulling 200 watts. I've seen them put put 20A peak per pack, but that will probably kill them. When I run them in parallel, I recharge in parallel too.

each 2p back has its own bms and yes i charge in parellel and they seem to discharge quite evenly as I meter this quite frequently to make sure

The cells in the packs are not crap, but they aren't really strong. I took two apart and made a 13S-2P (48V) battery with a good BMS, and found that when it got down to 46 volts, it would shut off from voltage sag. End of that experiment. It was 75 degrees that day too, How cold is it in NYC this week? 45F? That will kill range too.

Its been cold here...like 30s, but I have all the electronics in a tool box on a rear rack. When batteries are installed each or after charging they are room temp and full charge. The tool box is lined with a dense foam for protection and prevent banging aroung from vibrations and standard road transfer... I assume as well from constant use/discharge that the batteries stay warm and there really isnt a time where beyond 10min max where the bike is at rest and non-use...so i assume cold temps play a small roll but not as much as a typical exposed battery on a bik...BUT i could be wrong... thoughts there?

I'm thinking battery because two controllers and two throttles did the same thing. I do agree that 2.4V is low. Should be over 4 volts. You're getting 4.3 volts on the supply wire?