batteries again


Well, first off, my NiMH experiment on the 75C is working. I'm using a rat shack 23-270 3.6V 1200mAh batteyr pack, which fits fine in the 75 once you add a bit of padding for length.

the charger does charge, though slowly, and discharge takes forever.

I've got an HPIL printer (thinkjet) and one of the cellls in the battery pac has gone kaput (it was a rebuilt pac, 6 subC cells and I imagine one of the cells just lost it in shipping)

So now, a couple questions:

is it safe to run this off of wall current through the adaptor (with batteries disconnected.)?

and- is it worth rebuilding with NiCd? I can pop down and grab a pair of 3.6V 1200-1600mAh packs and easily fit them in the case of printer.

How bad is it to run NiMH cells in the circuit if you never really unplug the machine? (i.e., if I need batteries in there to run, can I just leave them in there?)

(and yeah, I've thought about taking a few of the small 3.6 volt cell phone batteries (lithium film) in the 2Ah range and using those, but do I need the battery life?)


and next time, I promise to be awake enoguh to not use a subject heading for my name.



We'll just refer to you as Batteries...again in the future


Now I need to fix a Lead acid Battery pack. I haven't found any direct references for doing it and haven't decided to just tear in there and spill electrolyte all over just yet.

Anyone rebuild one of these in the past?


The lead acid packs are not rebuildable... you must replace the whole battery. They are usually fairly inexpensive... the cell used in the 9114 battery holder is around $12.

Recently I picked up an early '70's Panasonic TV/AM/FM set that had two lead acid batteries in it. They looked like big 9V batteries, with the same type of snaps. These cells CAN be bought... for $150 each! The exact same cell with spade lug terminals were $13 each. Guess what... my TV now has spade lug terminals in the battery holder.


So, what's the voltage, and where do you order the replacement batteries from?



Christof, where do you live?
If you live in Germany I can give you some hints for buying the parts.
Regards, Andreas


In the US there are several nationwide chains of stores specializing in batteries. They have names like Batteries Plus and Batteries, Etc. You can take them just about any battery pack and they will open it, change the cells, and glue it back together for a reasonable price. They also sell many types of batteries including the lead-acid ones. Also just about every large city has a few industrial battery supply stores that will do the same thing and have access to even very exotic batteries.


I was looking online to order a similarly sized replacement and haven't found one yet that matches the size well enough. I may end up looking for a place that will pop the cells individually.

I'm pretty sure I recall some lead-acid battery reconditioning circuits, but only for 12 and 24 volt deep cycle batteries.....

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