<p dir="ltr">I have a vague memory of a rechargeable lantern battery at Frys. </p>
<div class="gmail_quote">On Mar 9, 2013 2:38 PM, "Ron Frazier (ALE)" <<a href="mailto:atllinuxenthinfo@techstarship.com">atllinuxenthinfo@techstarship.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
<br>
Alex Carver <<a href="mailto:agcarver%2Bale@acarver.net">agcarver+ale@acarver.net</a>> wrote:<br>
<br>
>On 3/8/2013 19:25, Ron Frazier (ALE) wrote:<br>
>><br>
>><br>
>> Alex Carver <<a href="mailto:agcarver%2Bale@acarver.net">agcarver+ale@acarver.net</a>> wrote:<br>
>><br>
>>> On 3/4/2013 21:04, Ron Frazier (ALE) wrote:<br>
>>>> Hi all,<br>
>>>><br>
>>>> A few months back, we had a thread here about new advanced LED<br>
>>>> flashlights. I bought one that has the giant 1/4 in LED inside,<br>
>and<br>
>>> is<br>
>>>> bright enough to be competitive with an incandescent krypton bulb.<br>
>>> Love<br>
>>>> the flashlight. Works great. However, it's powered by only 2 AA<br>
>>>> batteries and they're dying 6 months later. I'm considering using<br>
>>> NIMH<br>
>>>> rechargeables there. The problem with that is that, left on the<br>
>>> shelf,<br>
>>>> standard NIMH batteries lose 10 % - 30 % of their charge per month.<br>
>>> So,<br>
>>>> you could pick up the flashlight and not have it working when you<br>
>>> need it.<br>
>>>><br>
>>>> Enter Low Self Discharge NIMH batteries. These are relatively new.<br>
>>> They<br>
>>>> claim to lose only about 15 % of their charge after a year. So,<br>
>you<br>
>>>> could get away with charging the flashlight batteries only every 6<br>
>>>> months or so.<br>
>>>><br>
>>>> Two main brands of LSD NIMH seem to dominate. Eneloop by Sanyo and<br>
>>>> Imedion by Powerex (Maha Energy). I've used some standard Powerex<br>
>>> NIMH<br>
>>>> 2700 mah batteries and I like them, but I have to charge them if<br>
>>> they've<br>
>>>> been sitting a while.<br>
>>>><br>
>>>> Does anyone have any experience with the LSD NIMH batteries. Is it<br>
>a<br>
>>>> good idea to use them in a flashlight, or stick with Duracells at $<br>
>3<br>
>>> /<br>
>>>> pair, or other alkalines? I know Fry's and Home Depot / Lowes<br>
>>> sometimes<br>
>>>> sell batteries in packages at lower unit cost. I haven't done a<br>
>>> price<br>
>>>> analysis on those.<br>
>>><br>
>>> For something like a flashlight that can handle deep discharge try<br>
>one<br>
>>> of the lithium iron (that's Fe not a typo of 'ion') formulations.<br>
>You<br>
>>> can pick up AA versions at the hardware store next to the solar<br>
>powered<br>
>>><br>
>>> garden lights.<br>
>><br>
>> Hi Alex,<br>
>><br>
>> Thanks for that info. I did some research on these and they sound<br>
>interesting. The attributes of that battery chemistry sound cool and<br>
>it's probably worth keeping an eye on. I don't think it will work in<br>
>my case since these batteries are 3.2 V and my flashlight expects to<br>
>see 3X 1.5 V cells. I may end up going with some of the LSD NIMH ones.<br>
>><br>
>> Sincerely,<br>
><br>
>Ah, but you're missing half the fun of tinkering with the flashlight to<br>
><br>
>use them. :) A tiny, three terminal 4.5V regulator wedged inside and<br>
>you'd be set.<br>
><br>
<br>
Hi Alex,<br>
<br>
I'm not sure I need another project to tinker with. The flashlight I mentioned is one of the new high power led pocket units. There's barely room for the 3 AAA batteries in it. I don't think I want to mess with that. Also, if it's a linear regulator, it would be wasting all the power dropping from 6.4 V to 4.5 V. The only way you could avoid that would be a switching regulator.<br>
<br>
However, I have a couple of bigger flashlights that have the krypton bulbs and the big 6V square lantern batteries. The batteries are around $ 10 each. More than the flashlight costs. I had planned to decommission the units after the batteries die. A Lithium Iron rechargeable battery pack for those might be worth considering. I wonder if such a thing is already available in that form factor?<br>
<br>
Sincerely,<br>
<br>
Ron<br>
<br>
<br>
--<br>
<br>
Sent from my Android Acer A500 tablet with bluetooth keyboard and K-9 Mail.<br>
Please excuse my potential brevity if I'm typing on the touch screen.<br>
<br>
(PS - If you email me and don't get a quick response, you might want to<br>
call on the phone. I get about 300 emails per day from alternate energy<br>
mailing lists and such. I don't always see new email messages very quickly.)<br>
<br>
Ron Frazier<br>
770-205-9422 (O) Leave a message.<br>
linuxdude AT <a href="http://techstarship.com" target="_blank">techstarship.com</a><br>
<br>
<br>
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</blockquote></div>