TLP-15 Charger problem
 

I know it's not gun related, but it is somewhat airsoft related, to I'll give it a shot.

I've had this TLP-15 charger for quite a few years now, but I didn't use it much for the past two years. What's happening with it is that when I set it to fast-charge mode, it charges maybe 400-500 mah into a 5000 mAh NiMH then falls back into trickle mode, like if it already detected the voltage peak. I press the fast charge button again, once again it charges 4-500 mah, then back again to slow charge. The charge rate is set to the recommended rate of 3 amps.

First I tought that this might had been related to the fact that my batteries were old and defective, that's why I threw them away and got two brand spaking new Elite 5000, one being a 9.6V, the other being a 12V, both were bought from cheapbatterypacks and are wired with 14AWG and Deans.

Any help here?

what voltage reading are you getting when it stops fast charging? have you tried doing a discharge cycle?

3 amps seems quite high. I was told to charge at .5-1 amp. That means at 3 amps, you are charging a 5000 mah battery in a little over 1.5 hours. Once again, I may be wrong, since you are charging your cells at a high rate, maybe they are heating up too quickly causing the charger to kick off...

Charging a 5000 MAH battery at 3 amps is fine, it's reccomended you don't go over 1C (that's equal to mah/1000 = amp)

So in his case, he could charge up to a maximum of 5 amps.

Yep, I've discharged both batteries before charging (was quite fast as both came pretty empty, less than a minute of discharging in both cases).

In the case of the 9.6V battery, the voltage reading when the fast charging stopped was 13.5 volts. *Edit* The cut-off voltage for the 12.0V battery was 16.9V. *Edit*

The charging recommendations written on the cells are 3A for normal charging, 6A for fast charging.

If you discharged them, I do hope your cells are NiCad. Discharging NiMH cells basically ruins your battery pack.

They're NiMH, but this charger stop discharging before inflicting any damage to the cells, basically, when the voltage drops below 7.5V in the case of the 9.6V batt.

And also, as stated before, the batteries were pretty much already discharged, couldn't take a single shot out of any of them.

NiMH shouldn't be discharged AT ALL. As in NEVER. It ruins the cells. NiMH are best kept fully charged at all times.

haven't had an issue with a discharge cycle on any of my NiMH batteries.

The TLP-15 stops before it is fully discharged or goes into polarity reversal. (yeah I had to look it up to remember)

Now, you don't want to be doing a discharge cycle with NiMH all the time but I haven't had any adverse affects or longevity issues with the occasional discharge.

Lithium-Ion batteries are the ones that like to be charged and topped up 100% all the time. ie Cell phone and camera batteries.

Well, all this discussion about what the charger can do didn't cover what that charger of mine can't do ; properly fast-charge my batteries...

Back on topic, anyone has any idea of what might cause this behaviour? It's doing it with both brand new and old batteries.

Well the topic of discharging your NiMH batteries can screw them up, that's one scenario that could have happened.

try not fast charging the battery. let it trickle charge over night.

reading your first post again, it seems like you might have a bad cell or something in the pack.

so once fast charging is completed, you tried it again and it stopped after 400-500mah. cut off voltages sound about right but the batteries still don't have enough juice to fire the gun?