Mad bike riding scientist
Join Date: Nov 2004
Location: Denver, CO
Bikes: Some silver ones, a black one, a red one, an orange one and a couple of titanium ones
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Originally Posted by bmclaughlin807
So... no,, you DON'T have to match the amp hour(A/R) rating... the voltage rating of the new battery should be close to the old one, however. Slightly higher voltage will give a brighter light, but burn out your bulbs sooner.
For an MR11 halogen the life is shortened but it's not really that significant. I've been doing this for years to these lights and this year was the first time I've ever blown a bulb. I figure I got about 8 years of use out of that bulb. I might have shortened the life by a couple of years...no big deal really.
One thing you can do, Ronocerous, is to by batteries with a lower Ahr rating and either wire them in parallel or, perhaps better, switch them out when one starts to dim. I've done that for ever too. At All Battery, the low Ahr rating batteries are slightly cheaper.
To get an estimate of the burn time for a battery, use the following equation:
Hr run time = (Ahr x Volts)/watts of bulb
This is the best you can get but in real life the time is probably a bit shorter. New batteries, in particular, take few cycles to get to full charge.
Considering that you have problems with the charge on the battery, you might want to look at a new charger too. For NiMH, you should have one that monitors not only the charge but also the temperature of the battery pack.