J820 on AAA batteries?

BThepbroblem...whabtbtheb?aubh.Mykeyboardjusbtbroke!

Whoa, that sux.

Hey, cmonex, 15 C sounds kinda warm to me. Heck, it's colder than that outside my house right now (22:45 PDT).

CE Geek: who said li-ion likes cold?

Well, Jax does, apparently. My intuition was something like 5 C (refrigerator temp) - but I'm by no means an expert on batteries.

A lot of people do. Li-ions hate heat. The hotter they are, the faster they degrade. Look it up if you don't believe me.

Back to what I was trying to say earlier...
The problem with AA or AAA battery holders is that while they're easy to make, they quickly become more expensive than a new battery pack. Buying new AAs every few days is no fun. They'll also give around half the capacity of a li-ion pack.
Plus it would be very nearly impossible to make the Jornada charge Ni-MH batteries, so they would have to be taken out and charged in an external charger if you went that way.

I've never seen the inside of an 820's battery pack. Can you get us a picture of the cells?

Edited by Jax184 2007-04-20 3:18 AM

The external adapter is rated at 12V, 2.5A; if you figure it runs on half and charges with the other half, then it's running close to an amp. Or you could take the 7.2V 5.2Ah rating of the batteries and the run time and figure how many Amps it draws. The 5V isn't a big deal, one of the schematics used a programmable voltage regulator that could presumably be set to a different voltage.

I'll try to post a picture tomorrow.

Removing the batteries to charge might be an advantage -- you could bring a spare set along, you could still use the machine untethered while the first set was charging.

i didn't say they like heat. 15 C isn't exactly heat. if you had read my posts you'd see i agreed on they not liking the heat.

Edited by cmonex 2007-04-20 9:38 AM

ok, i know it is rated at 12V, i forgot you wanted it in place of the AC which is of course even more crazier

To something that freezes at -40, +15 is heat. A fully charged Li-Ion will degrade significantly faster at 15 degrees than at 0. But if the battery is only half charged, 15 degrees isn't much worse than 0.
Eather is still much much better than the ~45 degrees it'll encounter in a laptop.

There's at least a half dozen of them right now there, if you want to look for info.

Actually, I wasn't going to use it in place of ac, I was just using the rating on the adapter as a quick estimate of the power requirement.

Did you miss the part about how those are really only for the J928, which is a PDA, and are completely unsuitable for a J820?

Oh, you mean in your earlier comment. Yeah, good point - It looks pretty hard to squeeze four 18650s in that little enclosure. Duh.

Edited by CE Geek 2007-04-20 3:24 PM

CE Geek: they arent even 18650, as mentioned earlier in the thread.

Jax: i dont know who to believe, other experts or you.