Replacing the back-up battery in an Axim X51V - Page 2

Bill_Todd · 07-06-07, 02:27 PM

Originally Posted by goworley

I, too, am having the problem of losing date & time when swapping battery. Probably this is the cause. Now another problem...My x51v will not charge on the cradle & has to be charged by removing the battery & its being charged in the rear slot. Is this possibly related?? I must admit - my Axim suffered water damage & I thought all was lost. But I did get it up & running again. The charging problem cropped up about the same time. So, best guess, could the back-up battery be the cause?

I very much doubt the re-charging problem is caused by the back-up battery.

However, it seems likely to me that the cause of both problems could be the water ingress. Water, especially sea-water and even dirty water, will cause corrosion if not quickly and carefully removed. The corrosion will often take some time to cause noticable damage (often eating through power tracks on PCBs).

You would be well advised to take it to a repair shop before something else stops working.

Bill_Todd · 07-18-07, 11:18 AM

Originally Posted by Bill

I'll try to work out a way of measuring the capacity of the original device, as I'd like to know what is the cause of the problem.

Update:

All my attempts to measure the capacity of the old backup capacitor have led nowhere. I've come to the conclusion that this particular type of 'super-capacitor' is actually closer to being a 'battery' than a normal capacitor. (i.e. it appears to storage power via chemical reaction)

As far as I can see the capacity has been lost but it also has a higher internal resistance (spec is 200R this one appears nearer 2K)

lardo · 08-07-07, 04:04 PM

As a side note for people having this problem (me too). If you put your Axim in the cradle and do a synchronize, the date and hour will also be synched as well. No need to adjust it on your Axim...

jemoore77 · 08-30-07, 10:13 PM

I just got in my 0.22F, 5.5V Supercapacitor I ordered from Mouser Electronics tonight, soldered it in, and it seems to hold the system clock up fine (tested up to 60 secs w/main battery pulled, didn't lose time). Fit was very snug, in fact I had to melt away a millimeter or so of some of the internal plastic ribbing on the back cover to make it go back on all the way. But anyhoo, so far so good.

My soldering job leaves something to be desired, but I did snap a couple pix if anyone's interested, and the Supercap I used is P/N EDLSD224H5R5C, which costs about a buck plus shipping.

I had also ordered a larger 1.5F Supercap hoping I could somehow squeeze it in, but it didn't seem doable... :)

James

Benjamminz_IS · 09-25-07, 04:07 PM

Originally Posted by goworley

I, too, am having the problem of losing date & time when swapping battery. Probably this is the cause. Now another problem...My x51v will not charge on the cradle & has to be charged by removing the battery & its being charged in the rear slot. Is this possibly related?? I must admit - my Axim suffered water damage & I thought all was lost. But I did get it up & running again. The charging problem cropped up about the same time. So, best guess, could the back-up battery be the cause?

I would say yes... my previous axim suffered water damage and everything but backup battery lived... I do remember when I took mine apart originally to dry it out though it was a battery and not a cap... strange... anyways...

ericshliao · 10-07-07, 07:50 AM

Thanks for Bill's post. I replaced my X51v with a new 3V lithium battery (CR92). In contrast to Bill's sophiscated work, I brutally use a knife to cut off the battery and put the new battery back (with a small piece adhesive sponge on top to hold it). Even though the new battery is a little bit larger than the old one, It's works for me. Ha!

FunkyCowie · 10-10-07, 02:31 PM

I just posted dumb question... ignore me...

FunkyCowie · 10-10-07, 02:41 PM

I needed to pop out my backup battery because it appears to be causing the primary battery to drain from constantly charging it because it could be dying... maybe...

Interestingly on my backup battery it says:

VARTA V20HR

Made In Germany

So this is the battery/capacitor we/I should be looking for?

EDIT: after searching on the cpc site I came up with this

BATTERY, NI-MH HIGH RATE V20HR 1.2V
Depth, external:11.5mm;
Diameter, body:11.5mm;
Length / Height, external:2.2mm;
Width, external:11.5mm;
Voltage, output:1.2V;
Capacity, energy storage:20mAh;
Technology, Battery:Nickel

55902201012 | VARTA | Ni-MH (Nickel Metal Hydride) | Batteries & Power Supplies | CPC

EDIT EDIT: I am using a X50v... Just for the curiosity and the fact that I have WM5 installed I put my Ax back together and its fully functional without the backup.. no warning no nothing... why do we need a backup battery???

tw~ · 10-24-07, 08:22 AM

Originally Posted by FunkyCowie

EDIT EDIT: I am using a X50v... Just for the curiosity and the fact that I have WM5 installed I put my Ax back together and its fully functional without the backup.. no warning no nothing... why do we need a backup battery???

To keep the clock running.

FunkyCowie · 10-25-07, 04:14 PM

so your only access to the time is your PDA? Seems rather redundant... plenty of people around to ask the time... and if your battery is dead then you can't tell what time it is anyway on the PDA... so you charge it and ask someone the time and change it right?

kuifje_axim · 12-02-07, 03:30 PM

Hi,

I don't care so much about keeping the time while switching batteries, but do any of you think a leaky capacitor significantly reduces (main) battery life?

Galina · 12-17-07, 05:21 AM

Grate post, Bill!
Recently I started having the same problem and I am tempting to try your solution. Soldering bit scares me though. Today I was looking for screwdrivers and found pdasmart.com site. They list also backup batery for x50v/x51v for 20$ and description says "no soldering required". Strange...

Bill_Todd · 12-17-07, 10:00 AM

Quote:

They list also backup batery for x50v/x51v for 20$ and description says "no soldering required". Strange...

I suspect that part is for the X50 only, since the X51 super capacitor is quite different.

12-27-07, 11:21 PM

I replaced the super cap on my 51v tonight. So far, so good. I used a super cap made by Cornell Dubilier and available from Mouser Electronics. It cost $1.42 each. The super cap appears to be a direct replacement of the one that was in my 51v. The part number is EDLEN204RL3R3S. edlen204rl3r3s

Hardwarejunkie · 12-28-07, 03:39 AM

jhom,

Thanks for the informative post. You mentioned that it looks to be a direct replacement of the one that is in the X51v. I took a look at that super cap on the web site and saw that the tabs were not the same orientation as the original. I'm assuming you made some kind of wire to connect the negative tab over to the negative connection similar to what Bill Todd did?

Thanks,

Val