I'm thinking of using a coin cell battery retainer on an upcoming project. The target application will be in a medium-to-high vibration environment with around 1-2 years between battery changes. Unit will be in a dust-tight enclosure.

The retainer in question is MPD BK-5033. I'm concerned with maintaining good battery contact, as it powers a uC storing values in RAM. The application is very, very low power, and there are some capacitors to prevent millisecond length glitches. What bothers me is the idea of creating a pad on the PCB that has to maintain contact with the battery terminal.

If anyone has experience with this type of battery holder, I would love to hear any pointers.

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    \$\begingroup\$ No direct experience, but, since you mention vibration, I'd suggest soft-mounting the board and the battery holder to the case, and using flexible stranded wires, with slack, or even drip loops for strain relief, from the PCB to both battery terminals. Let the wires take the vibration. \$\endgroup\$ Dec 31 '13 at 4:32
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    \$\begingroup\$ @JohnR.Strohm OP is talking about a coin cell, with minimal access. They are typically board mounted, not in a holder/case. Your suggestions are better suited to large cells like AAA or bigger (or multiple button cells in series) \$\endgroup\$
    – Passerby
    Dec 31 '13 at 6:56
  • \$\begingroup\$ @Passerby - Correct, the coin cell is on the board itself. No wires are involved. \$\endgroup\$ Dec 31 '13 at 16:31
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    \$\begingroup\$ For what it's worth, the pcb contacts for the battery will last longer than the shelf life of the battery itself. Just make sure the contact is plated and not just pure copper. \$\endgroup\$
    – Passerby
    Dec 31 '13 at 17:16

For environments where vibration is a concern, it is better to use through-hole coin-cell retainers rather than surface-mount. The surface-mount retainers tend to produce dry solder issues over time when subjected to constant vibration.
We had used one retainer for a similar application few years back. The part number was 1025-7 from Keystone Electronics. It would be better to top it off with a thin layer of RTV just to ensure that it doesn't fall off during vibration.

  • \$\begingroup\$ Thanks for the info. The part I mentioned is actually through-hole, and its low profile is one reason I went with a retainer rather than a typical coin-cell battery holder like the Keystone part. My question relates more to the contact between the coin cell and the PCB pad. \$\endgroup\$ Dec 31 '13 at 16:28
  • \$\begingroup\$ As @Passerby has mentioned above, ensuring that the contacts are plated will help to maintain the contact to some extent. However, the retainer in question can still allow the coin cell to displace during vibration. There is a chance that the pads can get worn down after a long time. \$\endgroup\$
    – Avin
    Jan 1 '14 at 6:32

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