Mike Cane | # 11 | 2006-09-29, 20:40 | Report

Well, OK then, I'll be Stupid and just ask: Why not just buy and carry a second 770 battery? It's bound to be lighter and less bulky than any other solution.

Karel Jansens | # 12 | 2006-09-29, 22:00 | Report

You might be somewhere, for an extended period, where there is no AC current available. Just throwing a couple of packs of AAs in your backpack is more convenient, plus the emergency chargers usually come with adapters for other electronic stuff.

But, like I said, mine doesn't seem to work...

Mike Cane | # 13 | 2006-09-29, 22:49 | Report

Eh. I guess I'm not just Stupid, I'm Weird too. I carry the 770 AC adapter. I did look at what a 2nd battery cost at the Go-Go Nokia Store, tho. (You have to visit the Store to understand the Go-Go reference...). Of course, how would a 2nd battery be charged?

lbattraw | # 14 | 2006-09-30, 01:20 | Report

As a FYI you can get a nice, small AC adapter with two tips (Large, old Nokia style and new/small) for around $10 at Target. It took a little digging as they have a bunch of cell phone chargers but it does work very well and is small enough (Same size as one supplied with 770) to throw in a backpack/bag without taking up too much room. I also bought a couple spare batteries off eBay for $20 or so including shipping. Yes, not actual Nokia brand but they work great and don't even explode I'm a little mental about being caught out with a low battery, and carrying a spare is no hassle as they're so small/light. --Wish they'd fix the battery gauge to read closer to reality! Having it go from full to 1 bar left after a reboot stinks.

Larry

Odin | # 15 | 2006-09-30, 09:00 | Report

As stated in the "Gadget" review:

Really though, if you are the type to forget to charge your cell phone, you might forget to recharge your portable recharger, which will make it useless.

I see this as a great travel item along with a car charger and car chargerAC adapter. Of course, I have a Moto phone and headset.

Odin | # 16 | 2006-09-30, 09:06 | Report

I have the same problem. My Moto Razr is very, very fussy as to what it lets charge it, the 770 is similar but not quite as bad. My Uhura (H700) is the least picky of all and will charge from anything I plug it into that has power. It has to do with available current and you can only squeeze so much out of a few dry cells.

Karel Jansens | # 17 | 2006-09-30, 09:41 | Report

The 770 has a standard Nokia phone battery (I'm too lazy to look up the specs) that you can, relatively cheaply, buy in any phone store and, from the looks of it, from about half the population of Hong Kong on eBay. External AC-chargers for that type of battery are plenty, available from the same sources.

Karel Jansens | # 18 | 2006-09-30, 09:45 | Report

Funnily enough, my Nokillo isn't half as fussy about AC chargers: I've stuck anything from 4.5 up to 6.2 volts in it (including an old, universal, unregulated charger) and it will happily charge. But for some reason it senses it when I try to feed it from AA or AAA cells and barfs on it.

Maybe if I cover it with a cloth, so it can't see what I plug in...

Mike Cane | # 19 | 2006-09-30, 14:25 | Report

Given what's going on with batteries, I'd personally stick with Nokia. I'm not fond of electrons reaching critical mass. It also helps if a lawsuit is needed. Have fun suing the Happy Lucky Cheap Battery Company LLC of some place in Asia you can't find even on Google Earth!

lbattraw | # 20 | 2006-09-30, 14:27 | Report

The key to successful charging is current limiting. The reason batteries cause it to barf is because they can put out a ton of current as the 770 essentially connects them directly to the Li-ion battery in pulses. It measures that current going in and too much will force it to stop to avoid destroying things. You need something like a resistor to limit the current. The problem with a resistor is you automatically turn part of your power into heat, and to charge it in a reasonable amount of time you need a fair amount of current, thus producing a lot of heat (For 6V alkalines).
Off hand I seem to recall the voltage it drops to when pulsing is about 4.2V; 6 - 4.2V = 1.8V of difference. Assume you use a 4.7 ohm resistor, 1.8/4.7 = .382 amps, for about .69 watts. That's a fair amount of heat for a resistor in an enclosed space. Assuming your batteries were immortal and stayed at 6V the whole time it's going to take roughly 4.3 hours for a full charge (Assuming a 91% charging efficiency). If you wanted to be clever you could use a 3V flashlight bulb as a resistor, and then watch the pulsing current draw.
Questions? Standard disclaimer applies: Don't Try This at Home. May turn your 770 into a pool of smoldering magma, explode, or sterilize you at a distance of 50 feet. Please don't play around with this unless you're willing to chance ruining your 770!!!

Larry