[Nerull]

Hello again!
I have a sort of problem.
See, my JMT PiMETA (portable Hammond 1455 case) is wonderful in sound quality, but
the problem lies in its battery life. Around 2.5 to 3 hours.

(this is with 2 rayovac NiMH 9 volts). Does anyone have any suggestions
on what I can do? Otherwise I'm thinking of keeping that amp at home and
buying another portable amp (a supermacro or SR-71) but I'd rather not.
So, can anyone give me advice on some hi-capacity rechargable 9 volts?
(or maybe I'll open up the thing to see what other batteries could possibly fit...)
Thanks!

~Tom

 

[Pappucho]

Look at the mah rating when choosing longer lasting rechargeable 9V's. The higher the mah rating, the longer the battery will last.

Check out this site for rechargeable 9V's.

 

[Nerull]

Thank you!
I have another, more electrical question (this was the question I should've asked originally...)
Do NiCd keep their voltage longer than NiMH in an amp (or similar device)?

 

[episiarch]

My JMT Pimeta lasts a lot longer than that (on one 9V). Maybe only 8-10 hours, but still much more than 2.5 to 3. Perhaps something is wrong with it. What op-amps are you using? Mine's 8620/8610.

 

[Nerull]

I am using AD8620/8610 as well. I believe I have stacked buffers so that would probably kill some of the batteries' life. Would that do it?

 

[Pappucho]

Quote:

Originally Posted by Nerull I am using AD8620/8610 as well. I believe I have stacked buffers so that would probably kill some of the batteries' life. Would that do it?

That would definitely do it, especially if they are running in Wide Bandwidth mode.

 

[Nerull]

Alright. I'll probably just buy more batteries for the thing then.
Thanks for all your help!

~Tom

 

[episiarch]

I believe I have 2x stacked buffers (though I'm not sure).

If I were you I'd start by buying some disposable alkalines -- Energizer or whatever -- and see how long the amp runs. If <8 hours, suspect an amp problem. If >8 hours, suspect a problem with your NiMHs.

You might also PM or email JMT and ask him if he thinks the battery life on your unit is normal/expected.