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Old 1st Jul 2011, 2:02 pm   #20
broadgage
Nonode
 
Join Date: Jan 2010
Location: North Somerset, UK.
Posts: 2,129
Default Re: Battery Boxes.

As regards paralelling nickel metal hydride cells, the suppliers advise against it.
There should be no need anyway with modern high capacity cells.
Nickel metal hydride D cells are available up to about 9 amp/hour, and F cells still greater. That should suffice for almost any set intended for zinc carbon dry cells. This high capacity cells are rather expensive, but that should not matter if only 1 or 2 are needed.

AA cells can be used in series for HT supplies, and I would regard a fuse as vital if useing rechargeable cells, and advisable even with alkaline cells.
Modern alkaline cells can supply 10 amps or more, which is a lot of heat in a small space if something goes wrong !
A 100ma fuse would be advisable for HT dry batteries.
For rechargeable HT batteries, a ceramic bodied fuse listed for mains voltage should be used, again 100ma should be fine.
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