Backup Battery

Like most PDAs I've owned (my J720 and my Newton ) it has required a battery to keep the RAM from going dead when the main battery is low...but the strangest thing happens with mine, it will recharge itself inside my J720 when it is dead...I didn't buy a rechargable battery or anything and the ones before it were never like this.

(NOTE: I did pull the battery off of an old Dell computer's motherboard)

Most of the CD2032 button cells are non-rechargeable, but I do know that there are some makes that are rechargeable. So I won't be surprised if yours is recharging ...

wow, i want a rechargeable cr2032 are they very rare?

If you can find a 1998 Dell Dimension 450 with a PII 450mhz Proc...then you have one!
None the less I'm sure yanking one out of any old comp will do...maybe 'newer' systems used them because they charge and won't die for alot more time than other comps. If it's anything I hate it's a computer with a dead CMOS battery.

I've never heard of a rechargable CR2032 cell battery, but if there really is such a beast, it would probably be more expensive than just buying a disposible replacement, once a year. You would have to do a cost/time analysis, to see if it makes since to spend the extra money on the rechargable version.

In any event, if anyone finds one of these elusive batteries, please let us know!

They do exist, I've seen said monster.

But is it really just a case of passing a current over it to charge it, or would the cell slot need a charge circuit; especially as they're lithium?

http://www.aximsite.com/tutorials/index.php?qid=41&catid=2


PT630 Portable Data Terminal

On the other hand, I am not sure how many devices actually contains recharging circuits for the backup batteries. I mean, if it had recharging circuits, how would these circuits know when to recharge? If we put ordinary CR2032 inside, would these circuits (if they exist) send current in and start charging or not? ... Aren't non-rechargeable CR2032 meant to be *non-rechargeable*?

ah well, maybe some batt and charging expert can enlighten us ignorant common folks!

Weird, over the last few months my 6651 has alternately told me my backup batteries are low and I should change them, after a night on the charger they are back to full strength.

I *know* I killed them once, allowing my 6651 to totally discharge, and these are the same backup batteries. They're old, I pulled them from older m/bs some time back after I killed a pair that didn't revive. (That pair was a recent batch from a store) and replaced them with the current pair.

I've seen this on many m/bs that have been in mothballs. The battey won't hold CMOS data for a few days then suddenly all is well. I've never thought about it much till now.

I'm in my basement right now...lemme run upstairs and grab my J720...see what kind of battery we're dealing with...

*reads battery*
"Panasonic CR2032 3V Indonesia"

Heck maybe it's rechargeable, maybe it's a fluke that mine's working, no less, I'm glad it's charging because I let this thing die and I've killed and charged this battery at least 5 times in the past 6 months

*looks for these batteries on eBay...*

EDIT TO RESPOND TO WALLY:
Yeah - exact same thing to me...after a night on the charger the backup battery and main battery are back to 100% and "Very Good".

*Gets on Megaphone* EVERYONE HAGGLE YOUR IT GUYS AND GET THE CMOS BATTERIES!!!

Edited by bobbarker 2005-07-06 9:55 AM

well it can get better after a drain, even if it isn't a rechargeable battery.
you need to completely drain it if you want to make sure it is indeed rechargeable

hmmm ... not sure if its a good idea to completely drain it. Considering that li-ion cells (18650s) can go dead if drained completely, causing permanent damage!

ok, then *almost* completely.

Sounds odd to me. I have been in the battery business for quite some time and have never come across a rechargeable 2032. Ill check with some of my contacts Monday and find out.

Josh
service@thebetterbatterygroup.com
http://www.thebetterbatterygroup.com

All of the old Mobilepros (770-790) use a rechargeable LION battery, and the word rechargeable is printed right on top of it. They use a Toshiba IVR 2025s where the 20 is the diameter in mm and the 25 is the thickness as in 2.5mm. I found that the Panasonic ML2020 is a good substitute for the original. You can read about them here: http://www.panasonic.com/industrial/battery/oem/chem/lith/manglith.htm

2032s though are pretty darn hard to find them these days though. Here is one site that has them all: http://www.powerstream.com/licoin.htm Note that the voltage is 3.6V, but that is the max voltage...if you charge it to a lower voltage, it works fine as the cutoff voltage is less than 1V.

Rich

Edited by Rich Hawley 2005-07-09 7:24 AM

A bit OT, but thought I'd chime in with an anecdote. My parents' most recent ex-computer is my PII-350 440BX setup. Like their previous machine, an AMD 386DX40, the CMOS battery eventually went dead. My mom bugged me for months about having to reset the date everytime she would turn it on. I didn't want to bother, because one of the old motherboards I'd run across has a soldered CMOS cell--looked like one of the old cordless phone barrel batteries. (In fact, on one emergency occasion, I replaced a non-soldered version with a cordless phone battery--but I digress.) To my surprise, when we finally replaced my parents' machine, the old 440BX took two CR2032s. If I had known that, perhaps I could have saved the folks about $770. ;+

Oh well, the girlfriend is happy, because she has now inherited it and doesn't have to visit my apartment all the time to check her email!

Now, back to your regularly scheduled HPC2000 discussion.