Pimeta rechargable battery question

[velo1]

Hello, a few months ago I built a pimeta amp and added a trickle charger as described by Tomb using the same Tenrgy batteries and regulated power supply shown in the post(s). At first, the batteries would only last an hour or so with a full charge. I checked voltage of the batts. after charging and they read 10 volts. After discharging and recharging a few times, the batteries would hold a charge for a longer period of time and I enjoyed using the amp

. I did not listen to the amp for awhile and left the charger plugged in. Last night I decided to use the amp. I unplugged the charger and turned the amp on. The LED was dim and the amp played for about 15 minutes before dying

. I plugged the power supply into the amp and it sounded fine and played for hours. Did I kill the batteries by leaving the power supply plugged in for weeks? Can I "bring them back to life", or do I need to buy new batteries?
Thanks!

 

[vixr]

I would bet you killed em...

 

[tomb]

Yes, I agree with Vixr. Unfortunately, you may have discovered the limit for how long you can leave a trickle charger plugged in.

 

[MASantos]

x3

I still think we should get together and design a smart charger board that would be somewhat customisable similar to Tangent's PPA battery board but without the battery holders. If we use some SMD (SOIC IC's and resistors) we could get the board small enough to incorporate in popular portable/transportable designs.

 

[vixr]

Quote:

Originally Posted by MASantos /img/forum/go_quote.gif x3 I still think we should get together and design a smart charger board that would be somewhat customisable similar to Tangent's PPA battery board but without the battery holders. If we use some SMD (SOIC IC's and resistors) we could get the board small enough to incorporate in popular portable/transportable designs.

I actually have started this idea on perf... I have the ICs from Tangents PPA board and just haven't finished it yet. I want to charge 10 AA NiMH in about 3 hours...

 

[FallenAngel]

Quote:

Originally Posted by tomb /img/forum/go_quote.gif Yes, I agree with Vixr. Unfortunately, you may have discovered the limit for how long you can leave a trickle charger plugged in.

Wow, I certainly hope not, I've ran my Pimeta off a TREAD with a trickle charger charging the batteries for days at a time, probably taking it off the TREAD only once in a while. Hope the batteries can survive it

 

[vixr]

my NiMH 9v batteries say 14mA for 14 hours only...

 

[velo1]

Thanks guys! I'll order another set of batteries and disconnect the charger more often. I was thinking of going to LiIon batteries. Would I have to change anything as far as the charging circuit goes? Is this a dumb idea?

 

[MASantos]

Quote:

Originally Posted by velo1 /img/forum/go_quote.gif Thanks guys! I'll order another set of batteries and disconnect the charger more often. I was thinking of going to LiIon batteries. Would I have to change anything as far as the charging circuit goes? Is this a dumb idea?

Yes, LiIon are completely different form Nimh. They have different charging methods which require specific charging circuits. Using a LiIon batt with a NImh charger probably result in damaged bateries or even an explosion.