ST-1 Troubleshooting

[Tombike]

Hi, I need some help with my bike. I recently got a hand me down ST1, but it is not responsive. Battery (gold variety) reads ~5v on my hand-held volt meter. Most likely this is why the computer won't start. I have a Stromer charger (the one without an "on/off" switch, and one light that is either green, orange, or red). When I try to charge the battery, the light is red for about 5-10 sec (presumably sensing voltage), then the light turns green, indicating the battery is charged (or more likely that it is not charging the battery). I have only tried to charge the battery connected directly to the charger. I assume the battery is dead and I will have to buy/build a new one, but is the charger behavior normal? I would guess that it would try to charge, but after many hours a dead battery will remain dead. In my case the charger seems to give up so quickly.

Also, looking at the bike, I can see several unconnected plugs; I am wondering what are these for? One is a 3-pronged plug in the battery compartment. The other is a small 2 prong plug that protrudes through the bottom of the frame below the pedals. See my photos. Should I connect these to something? Can I diagnose problems with these cables?

Any suggestions are helpful.

 

[Tombike]

Ok, I guess my cable question is answered here. They are for a light kit.

/threads/questions-about-unused-connectors-what-are-they-for-st1.16338/

Any one have experience with battery or charger?

 

[opimax]

A completely dead battery over 5years old does the same dance when I try to charge it. There may be a date code on the battery you can read. If over 3 years and don’t know the last time it was charged , pretty decent guess it is a defective battery.

 

[Tombike]

Thanks Opimax. I'm guessing your charger is still working well with batteries that are in good shape. Looks like I'll be looking into battery options then.

 

[opimax]

Where are you? Maybe a local person could let you test their battery, maybe a shop too. It won’t take long to verify , try your charger on their battery and their charger on your battery. Maybe go for a a ride around the parking lot in view to keep them from becoming nervous to check out the rest of your bike.