A CMOS Battery Quiz! *PIC* (45KB)

[rkawakami]

I'm having a problem communicating a point to an eBay seller of Thinkpad CMOS batteries. This seller has been mentioned here a couple of times so I know some of the members have had dealings with them. While going through my Thinkpad inventory, I discovered that some needed a fresh CMOS battery. I found a lot (10 pieces) of the batteries on eBay by searching for the laptop name. The title of the auction specifically listed what type of system the batteries were for (and exactly what I wanted). What was pictured in the auction and what was listed for the other Thinkpad systems the batteries were supposed to used with, was, in my opinion, wrong. I didn't have a problem with the fact that they used a "stock photo" of a CMOS battery. What I was worried about was that they listed several other Thinkpad series as being compatible with the type of battery I needed. Having owned most of the other systems they listed, I knew that to be false. I contacted them and specifically asked them to view this photo:



and to confirm that what they were going to provide to me was equivalent to battery "C". (My original picture had all of the IBM FRUs displayed. For this quiz I've masked those numbers but left the CRxxxx numbers.). Their reply was: "based on our technical department, the black battery on the right is compatible in our CMOS Battery.". Given this I went ahead and bought the batteries, figuring they knew what they were doing; over 35,000 transactions and a 99+% feedback. I was quite surprised and disappointed to receive battery "A". I pointed out to them that "A" and "C" were different in one critical respect. They replied that their technicians said "there should be no problem" and that I should look at another auction they had going, using the logic that, "as you can see, one is listed as XXX and one is YYY, but uses same piture meaning they're just the same.". Oh, they also asked if I had tried installing the battery. I politely told them their techs were wrong, reiterated my original points and asked to see what they were selling in the other auction. This is what they sent me:



And now for the quiz:

1) What systems are compatible with battery "C"? The choices are A2x, A3x, T2x, T30, T4x, R40, R5x, X2x, X3x, 560, 570
2) What systems use battery "A"? (Same choices as above)
3) What systems use battery "B"? (not really relevant to my problem but it's in the photo and, hey, this is a learning exercise )
4) What is different between batteries "A" and "C"?
5) If it is possible to plug battery "A" into a laptop that normally uses battery "C", what would happen?

[RealBlackStuff]

1) The R40 uses 'C'
2) 'A' is used in A2x, A3x, T2x, T4x, R5x, most likely also in X2x and X3x.
3) Haven't seen any with 'B'
4) Difference is polarity of the cables (+ and - swapped)
5) Probably blow the CMOS and a few other bits

[Neil]

My guess would be that "B" is for the 600 series, and maybe some others. And I'm with RBS on the other points.

[Unknown_K]

B looks like a 600 series Thinkpad CMOS to me.

As far as using the wrong battery or switching the leads, as long as the voltage is not that far off from what it should be you will probably not harm anything but the machine will not keep correct time when shut off.

[alkemyst]

The 'motherboard connector' can be swapped or removed..the pin spacings AFAIK are the same, it's just the male / female plastic parts that differ.

Still on eBay (and I have had really good luck for a decade+ for almost everything else), thinkpad items are problematic. If you search T60 SXGA LCD cables you will find most are selling the R60 type which is not the same. I have had some good luck on ebay though, but it's a 50/50 average now on getting the right part or not.

[mediasponge]

If A and C use the same connector body, the metal pins can be popped out of the body and swapped to fix the polarity. No need to cut, no need to resolder. I couldn't tell you how many times I've done this with desktop HDD LED connectors...

A magnifying glass and a dental pick should be all you need, as long as you have 3 hands.

[Unknown_K]

If A and C use the same connector body, the metal pins can be popped out of the body and swapped to fix the polarity. No need to cut, no need to resolder. I couldn't tell you how many times I've done this with desktop HDD LED connectors...

A magnifying glass and a dental pick should be all you need, as long as you have 3 hands.

2 hands work ok, you just need a needle to lift the plastic bit on one side and slightly pull to remove the wire.
Once you do a few its not bad. Some ebay sellers of backup batteries tend to send the wrong ends sometimes, so you need to reuse the old batteries connector.