What's the best 2 or 4 AA mobile USB charger?

computerpro3

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I'm looking something mainly to keep my usb gadgets running in case of an extended power outage or backpacking trip, so it must be reliable. I tried the duracell "My pocket charger" but it's a piece of junk as it requires a total voltage of 2.8V to turn on, meaning it doesn't work with even slightly depleted eneloops.

I need something that is reliable, takes 2 or 4 AA's (small size is nice for EDC), and that works with nimh rechargables/alkalines/L91 lithium primaries.

What are you guys using?
 

computerpro3

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I order the eneloop mobile booster. It looks like it's the most reputable option.

I tried using my L91's in the duracell my pocket charger while waiting for the mobile booster to come in, and the batteries got REALLY hot - why does this happen? Will I be able to use L91's in the incoming Sanyo booster?
 

NutSAK

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Using batteries to charge batteries seemed pretty pointless to me, since the circuitry is usually very inefficient.

A solar panel charger seems pointless to me when it's dark. In that situation, I'll take the inefficient AA charger over the inoperative solar one.
 

andrewnewman

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I order the eneloop mobile booster. It looks like it's the most reputable option.

I tried using my L91's in the duracell my pocket charger while waiting for the mobile booster to come in, and the batteries got REALLY hot - why does this happen? Will I be able to use L91's in the incoming Sanyo booster?

Ack! I believe you are trying to recharge lithium primaries (L91 batteries). Do not EVER place these in ANY recharger. Seriously. They will heat and vent both flame and toxic fumes. Please PLEASE read up on this. These batteries CANNOT be recharged. Sorry to sound so alarmed but we've had a few too many fires, explosions and "near misses" on CPF of late!!!
 

computerpro3

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Ack! I believe you are trying to recharge lithium primaries (L91 batteries). Do not EVER place these in ANY recharger. Seriously. They will heat and vent both flame and toxic fumes. Please PLEASE read up on this. These batteries CANNOT be recharged. Sorry to sound so alarmed but we've had a few too many fires, explosions and "near misses" on CPF of late!!!

:laughing:

Thanks for your concern, but I'm not that dumb! I'm not trying to charge the batteries, I'm trying to use the L91's in a device designed to put out USB current from AA batteries to charge a cell phone.
 

Mr Happy

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Thanks for your concern, but I'm not that dumb! I'm not trying to charge the batteries, I'm trying to use the L91's in a device designed to put out USB current from AA batteries to charge a cell phone.
The USB mobile chargers put a heavy load on AA cells and L91's have a relatively high internal resistance. This causes them to warm up when subjected to sustained high currents.
 

computerpro3

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Thanks, that makes sense. Now I ordered the Tekkeon Mp1550 too as I'm concerned about the Sanyo's ability to reliably charge my phone (which sometimes draws MORE than the USB 500ma) with only 2 batteries.

I hate this forum... :p So much money gone!
 

JollyRoger

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http://www.amazon.com/dp/B000XSBVK2/?tag=cpf0b6-20

you can find it cheaper (closer to $20 or $25) sometimes.

It puts out clean USB power. No problems charging my Palm Pre.

I like how it also charges AA and AAA's and has 4 independent charging channels.

a bit bulky, but all-in-one solution. there is a flip out ac prong on the back. you can plug it into the wall and use it to charge the AA or AAA's or use it as a wall USB power source, too.
 

computerpro3

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Got my tekkeon, and it appears to work great with eneloops.

One thing though - it gets wicked hot when charging my phone. Is this normal? It is almost painful to the touch near the usb port.
 
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NutSAK

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Mine also does not get hot, but the temp would probably be dependent on the current draw of the unit you're charging.

I like my Tekkeon MP1550 but, IMO, it should only be used to charge AA batteries in an emergency situation, and with depleted cells.
 
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Lynx_Arc

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http://www.amazon.com/dp/B000XSBVK2/?tag=cpf0b6-20

you can find it cheaper (closer to $20 or $25) sometimes.

It puts out clean USB power. No problems charging my Palm Pre.

I like how it also charges AA and AAA's and has 4 independent charging channels.

a bit bulky, but all-in-one solution. there is a flip out ac prong on the back. you can plug it into the wall and use it to charge the AA or AAA's or use it as a wall USB power source, too.
I have one of these, the AC plug can be removed completely I use a wallwart on mine instead so it sits flatter and I removed the cover as I don't see a use for it sitting flat on a table.
 
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Bones

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http://www.amazon.com/Duracell-Charger ... CEF23DX2

You can find it cheaper (closer to $20 or $25) sometimes.
...

Here's a link to the version of the mobile charger that includes 4 pre-charged cells (2xAA & 2xAAA) and the auto-adapter. Prices are currently starting at about 18.00. I found it by searching for CEF23, which is the designation for the base model, and then looking for the DX4N extension (CEF23DX4N):

http://www.amazon.com/Duracell-Charger ... CEF23DX4N

I have one of these, the AC plug can be removed completely I use a wallwart on mine instead so it sits flatter and I removed the cover as I don't see a use for it sitting flat on a table.

For what it's worth, there are indications that chargers that come with covers may actually rely on them to terminate properly:

http://www.candlepowerforums.com ... post3286742

http://www.candlepowerforums.com ... post3070129
.
 

Lynx_Arc

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For what it's worth, there are indications that chargers that come with covers may actually rely on them to terminate properly:
I haven't had any problems with termination charging rayovac hybrids and some generic 1600mah nimh cells with the cover off they stay cooler. I read those two threads some and the chargers mentioned were the duracell power gauge and a sanyo charger not the duracell mobile charger. It is possible the charge rates (ma/hr) is different on the chargers maybe lower on the others causing them to charge slower and heat up less.
 
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