3.6v rechargeable CMOS battery 80mAh NiMH for vintage motherboards & PLC

Description

Superior quality, freshly manufactured.
Shipped pre-charged and tested just before shipment.
The latest NiMH chemistry.
Perfect drop-in replacement for vintage 3.6v NiCd 60mAh batteries — same physical dimensions and voltage.
NiCd battery chemistry is being phased out worldwide because cadmium is a toxic environmental hazard. Batteries I've seen in the past few years still labeled as NiCd are actually NiMH (which you can see if you peel off the plastic wrap and look at the stamped designation on the batteries).
Dimensions: Sits about 15.5mm high when installed in circuit board and about 15.5mm wide. Distance between pins (and length of battery) is about 19mm. From all the vintage motherboards I've seen (and I've seen many thousands in my long career) this seems to be the standard size for these batteries.
Procedure:
Desolder the old battery, being careful to note the old battery's polarity before removal (one end will probably be marked with a "+" and the motherboard will probably be marked on the "+" side).
If high melting point lead-free solder was used on your motherboard, you may find it difficult to melt. Trick: melt standard low temp tin/lead solder onto the lead-free solder. This provides better heat conduction between the soldering tip and the existing solder. The solders will mix, lowering the melting point of the existing solder and allowing you to more easily desolder.
Using solder wick or solder vacuum tool, remove old solder from circuit board contacts. Make sure the solder is removed from the the holes so the pins of the new battery can be inserted.
If the old battery leaked, use an old toothbrush and isopropyl or denatured alcohol to clean the circuit board. If the battery leakage caused corrosion damage to circuit traces, you may need to repair and replace the damaged traces with a fine wire.
Insert and solder in the new battery using proper soldering techniques, making sure to observe correct battery polarity.
Be sure to use non-corrosive flux designed for electronic circuits and a suitable soldering pencil or soldering station. Excessive soldering heat will damage the battery and/or the circuit board traces.
We hope the procedure outlined above may be helpful, but we cannot provide additional assistance or support.
When powered on, the motherboard provides a slow trickle charge to the battery to maintain the full charge. When the computer is powered down, the battery provides the power required to maintain the CMOS settings as well as power the RTC (Real Time Clock) to maintain the current date & time.
Note: color and appearance of the battery may vary from the photo, but the dimensions and other specifications will be the same.
Manufacturers worldwide are switching from NiCd to the newer NiMH technology -- and for this particular purpose the two types are interchangeable. Explanation:
You've probably heard that NiMH batteries cannot be charged in a NiCd charger, and this is indeed true for high-speed chargers. The reason is that high-speed battery chargers must be able to detect the small voltage drop that occurs when a battery reaches its full charge capacity so that it can stop charging (overcharging damages the battery). Older high-speed NiCd chargers usually are only able to detect the relative large voltage drop occurring when NiCd batteries reach a full charge, but most cannot detect the much smaller drop of a NiMH battery -- so the charging continues and the NiMH battery is overcharged (damaged). Note that newer fast chargers designed for NiMH batteries also work fine with NiCd.
A motherboard uses only a very, very low and steady trickle charge current which is just high enough to maintain the battery in a fully charged state, but not high enough to overcharge. Trickle chargers are very simple designs and do not detect anything. NiCd and NiMH batteries are interchangeable for use with trickle chargers such as used in motherboards.
There are other small differences in the two battery chemistries, but the voltage is the same and for this purpose they are completely interchangeable.
Domestic shipping via USPS First Class Package with tracking.
Due to the nature of this item and the varying skills of buyers, this item cannot be returned for any reason if it shows any evidence of having been installed.
Note: Purchaser is responsible for determining compatibility before bidding. We are not responsible for compatibility issues.