TrustFire TR-001 Charger Not Fully Charging

[lewong]

I have a TrustFire TR-001 charger that I bought in December 2007. I have used it with protected and unprotected batteries. I've never let any of my Lithium Ion rechargeable batteries go below 3.7V.

Using a Fluke 115, the voltage of batteries, when the LEDs were solid green, was always very close to 4.2V - maybe at most 4.215V.

Recently, I noticed that voltage of the batteries off the charger (and after an hour or a day), when the LED is solid green, is less than 4.1V, generally about 4.05V to 4.08V.

The voltage for the each channel with no load is 4.586V and 4.612V. The charging current for a partially discharged battery (3.9V) is 125mA.

This means the batteries are not fully charged when the LED is green because they are not reaching 4.2V when the LED is green. If I leave the batteries on the charger, they will continue to charge very slowly, taking 30 minutes, for example, to go from 4.080V to 4.125V. The batteries will hold 4.125V or 4.2V if I wait long enough for it to charge to that voltage. The measured the current through an AW 16340 when the LED is green is less than 50mA.

The charger has never overheated, and the LEDs seem (i.e., they are amber when charging and change gradually to green) to work except for indicating full charge.

So is 4.08V enough of a charge? Is it time for a new charger? Otherwise, I would have to monitor the charging rate by measuring the voltage.

Thanks.

 

[SilverFox]

Hello Lewong,

Keep in mind that as Li-Ion cells age, their full charged voltage drops. If the charger has been working well, and if you haven't dropped it, it may be that the cells are wearing out.

You may want to purchase a new cell and see if it charges up to 4.2 volts. If it does, then your other cells have aged.

Tom

 

[lewong]

Thanks, Tom, for your help.

Some of my batteries are older, but I have two AW 16340s and one AW 18650 that have I've recharged less than ten times.

I guess the charger is just switching from 125ma charge rate to 50ma sooner. It's taking longer to get to 4.2V.

I've read a lot of threads about problems with these charges but mine has been fine for two years, so I guess $9 for a new one isn't a big deal.

I just noticed on the label, that the output should be 500ma, maybe that's the problem.

 

[old4570]

Thanks, Tom, for your help.

Some of my batteries are older, but I have two AW 16340s and one AW 18650 that have I've recharged less than ten times.

I guess the charger is just switching from 125ma charge rate to 50ma sooner. It's taking longer to get to 4.2V.

I've read a lot of threads about problems with these charges but mine has been fine for two years, so I guess $9 for a new one isn't a big deal.

I just noticed on the label, that the output should be 500ma, maybe that's the problem.

2 years for $10 = Priceless

Buy a new one ... :thumbsup: