Taperssection.com
Gear / Technical Help => Remote Power => Topic started by: travelinbeat on July 19, 2011, 08:28:39 AM
-
Any recommendations? I know the Sanyo 2700 are top of the game for AA's, but I'm looking to get 6 AAA's to keep in rotation for my flashlight.
-
I use and can recommend Maha/Powerex Imedion for rechargable NiMH AA's, AAA's and 9.6V's. Imedions are low self-discharge type and have performed very well for me. They're comprable to Sanyo Eneloop. I use Maha chargers with all of them, but the only ones that actually require a dedicated charger are the high voltage 9.6V's.
-
Thanks for the recommendation! I'm noticing that Powerex makes more AAA's than the type you've recommended and that some of their other AAA's are up to 1000mAh (compared to yours, which are 800 mAh). I am no power genius, but as I understand it, it's generally a good rule of thumb that higher mAh is better. Could you expand on what makes this lower power capacity battery better than the higher capacity battery?
EDIT: and my charger is the MHC-9000: (http://www.mahaenergy.com/store/catalog/mhc9000.jpg)
-
mAh = milli Amp hour.
More = longer run time.
Think of it as the size of the batteries gas tank.
-
mAh = milli Amp hour.
More = longer run time.
Think of it as the size of the batteries gas tank.
That's what I've always understood to be the case and it makes me wonder why someone is recommending a lower than optimum mAh battery.
-
The Immedion batteries use a different formulation that allows them to retain their charge for a longer period of time. "normal" nimh batteries start to self-discharge pretty quickly and generally become pretty fully discharged within a month -- I'd personally trade a bit of ultimate capacity for the charge stability permitted by an extended charge formulation as I've had a bit of concern regarding "topping off" partially discharged nimh batteries a few weeks after recharge.
-
That's definitely an interesting trade off.... I may have to think about what means more to me. The application is a Mag-Lite LED XL-50 flashlight, if that makes any difference in the consideration.
-
If for a flashlight, I'd go with the ones gutbucket recommends. even at 800mah, they're comparable in output to alkaline aaa batteries and would demonstrate comparable shelf life to alkaline aaa batteries. In other words, if you went with "normal" nimh batteries and hadn't charged them for a few weeks , the batteries' self-discharge "feature" would likely have eaten much of their underlying capacity and cause the flashlight to die pretty quickly (regardless of mah rating) -- otoh, with the slow discharge batteries, you'd be a lot closer to the initial charge capacity and would enjoy a brighter life . . .
-
mAh = milli Amp hour.
More = longer run time.
Think of it as the size of the batteries gas tank.
That's what I've always understood to be the case and it makes me wonder why someone is recommending a lower than optimum mAh battery.
LSD - Low Self Discharge batteries are what you really need. These are typically lower mAh batteries but they ultimately hold their charge longer.
The Sanyo Eneloop series are great LSD batteries, search for them. . .
edit to add:
You can buy them from Amazon link here or elsewhere (http://www.amazon.com/SANYO-eneloop-Pre-Charged-Rechargeable-Batteries/dp/B004SB1TD4/ref=sr_1_1?ie=UTF8&qid=1311093150&sr=8-1)
(http://g-ecx.images-amazon.com/images/G/01/electronics/detail-page2/Eneloop3yearchart.jpg)
-
It's true that the self-discharge rate of nimh batteries is a significant consideration.
Good flashlights have regulators to maintain consistent output even as the battery voltage drops, and to account for the voltage difference between alkaline vs. nimh.
Junk flashlights do not. A lot of flashlights have cool looking machined cases but junk internals.
It makes a big difference. Fortunately, the common flashlights are getting better.
Sites like candlepower forums measure flashlight output as the cells discharge, etc. You might check over there for battery recs.
-
The Immedion batteries use a different formulation that allows them to retain their charge for a longer period of time. "normal" nimh batteries start to self-discharge pretty quickly and generally become pretty fully discharged within a month -- I'd personally trade a bit of ultimate capacity for the charge stability permitted by an extended charge formulation as I've had a bit of concern regarding "topping off" partially discharged nimh batteries a few weeks after recharge.
Also, in my experience, low self discharge batteries like the Immedions seem to last a lot longer before going bad. I had a lot of regular NiMh's lose a lot of capacity well before their time.
I will never use anything but batteries like the Immedions in the future.
-
Very good discussion, thanks for it! I may very well be sold on the 800's now 8)