LowPowerLab Forum

Hardware support => Low Power Techniques => Topic started by: joelucid on March 04, 2016, 03:01:28 PM

Title: The case against the coin cell holder
Post by: joelucid on March 04, 2016, 03:01:28 PM
http://cdn.spectrumbrands.com/~/media/Rayovac/Rayovac%20Industrial/Files/technical%20oem/Lithium%20Carbon%20Monofluoride%20Coin%20Cells%20in%20Real.ashx

Potentially selective perception - but anyway here it goes:

"Although it may be one of the least expensive ways to connect a battery into a circuit, coin cell holders, Figure 6, are also one of the least reliable methods. The reliability of the coin cell can be compromised due to a loss of contact between the cell and the holder.
Another failure mode of coin cell holders is oxidation of the contact material. The oxidation of the contact material can be caused by environmental or mechanical influences. Environmentally, humidity can cause oxidation of both the contact and even the cells surface if it is prolonged and severe enough. It is the mechanical influences, that most often lead to failure."
Title: Re: The case against the coin cell holder
Post by: WhiteHare on March 05, 2016, 12:09:34 AM
Yup, and when it comes to the effects of moisture/humidity on contacts, it's not just coin cell holders either.  Tabbed batteries soldered to the board would be great, but short of that, sealing the contacts with impermeable waterproof epoxy should--I'm hoping--also work (cf https://lowpowerlab.com/forum/index.php/topic,243.msg11809.html#msg11809 )  In the end, though, I'm discovering that the epoxy cost may actually be more expensive than, or at least comparable to,  buying new tabbed batteries.   :(  Hence, I'm searching for a less costly way to weatherproof.