Questions about portable chargers.

[Bill M]

I purchased two chargers, the Duracell Instant USB and the Tekkeon mp1550.

The Duracell Instant charger is a lithium battery that holds 1150Mah of power. It's very slim and light and fits in your pocket comfortably. This charger will only charge my phone (motorola droid) about half way.

The Tekkeon charger is a little bit bulkier, it holds 4AA batteries and the casing is just about an inch bigger than the AA batteries and about 3/4 of an inch thick.
I am using some cheap brand AA low self discharge batteries they are rated at 2300mah but I have tested them to be at about 2000 to 2100mah with a lacrosse charger. I am only getting about 1 complete charge out of a set of batteries. Is that normal? I figured if the Droid battery is 1300mah and I am using 4 2000mah batteries I should at least get 3 full complete charges shouldn't I?

Anyway, unless I have a faulty tekkeon unit I think I would prefer to carry around two of the duracell chargers because they are smaller and lighter.

Any thoughts, or suggestions on other portable chargers?

 

[Samstag]

The batteries in the Tekkeon are going to be in a series arrangement to produce 4.8-6 volts at 2000 mah total. One charge is all you can expect from it.

To increase capacity with multiple batteries they need to be arranged in parallel, which would give you 1.2-1.5 volts at 8000 mah or 2.4-3 volts at 4000 mah. But since you need near 5 volts to charge the droid 2000 mah is the best you're going to get with that device.

 

[Bill M]

Thank you, I guess I just didn't understand the math involved and the different voltages. I guess the Tekkeon can come in handy when I'm on vacation and I can carry some spare batteries, or I could even buy regular AA's in an emergency.

 

[dakster]

battery tip

Alkaline batteries won't work in the mp1550 for a high current device like the droid. Just found this out on a trip to the west coast. Alkaline batteries will be dead in about 40 minutes, and only give you about a 30% charge. They'll also be hot enough to practically melt plastic heh.

I'm using 2700ma powerex rechargeable batteries now, and they seem to be just fine. Think I'll get at least 1 full charge out of them, if not a little more, plus they run much cooler.

Can always carry more rechargeable batteries to swap out. The mp1550 is a good deal imho, they're only $20 on newegg, and quality rechargeable batteries aren't expensive either.