Battery Won't Charge Past 3.9 Volts!?

[nodramaclothing]

Its a brand new Sanyo 18650 on a brand new Trustfire TR-001. Charged initially for 12 hrs and the red light never turned off, so I put it in my APV and read-out was 3.8 volts. I used it for 20 mins or so and It dropped to 3.7v. I put it back on the charger and let it charge again. Its been on for an additional 9 or 10 hrs now and still have a red light. I took it off to check at around 4 hours and it read 3.9v. Just checked it again and ..... 3.9v still. Any Ideas?

 

[rolygate]

What happens to other batteries in that charger?

1. If the same happens to other batteries then the charger is faulty. It should charge to somewhere between 4.16 volts (gives maximum battery service life) and 4.21 volts (gives maximum charge per cycle but approximately halves battery life). Charging at 4.22v or above is a charger fault, don't use it as battery life is significantly reduced.

2. If it only happens with this battery, the battery is dud and should be scrapped.

3. If the battery charges correctly on another charger but not your TR1, that would indicate an unusual situation that needs more data to resolve.

With an APV you need multiple batteries, a multimeter, and more than one charger. It's very hard to work out what is going on unless you can substitute all elements.