Key Fob batteries
Safety Car
Joined: Dec 2012
Posts: 3,871
Likes: 1,870
From: St. Louis Metro East IL
One of my daughter's Subie fobs was low - 2.89v. Just changed batteries in 9 fobs including the 2019 GS. All new batteries EEMB 2032 tested 3.30v or better. Curiously, the Forester manual says fob battery only lasts 1 - 2 yr - daughter got just under 2 yr. There is a button sequence to put Subie fobs to sleep and save battery life. I thought Vettes ate fob batteries, but ...
Let me know how you make out.
Ron
Let me know how you make out.
Ron
Melting Slicks
Joined: Feb 2018
Posts: 2,193
Likes: 1,055
From: North Texas
These and all 'small' batteries really need to be tested with a load on them.
When testing a battery, 1.5v, 9v, they need a load to determine if they are really good.
FYI: HF has a very cheap DVM that has a function that does exactly that. A different load for each of the 2 voltages that I mentioned. (But no setting for 3v cells, I wish they did). Think of this feature as the same as a load test that would be performed on your 12v lead acid cranking battery but in these small batteries the HF meter just uses a smaller current drain.(I believe it's 4mA for 1.5v cells and 25 mA for the 9v cells).
Remember the battery has to retain its voltage and also produce enough current for the electronics to work.
When you use a modem DVM, most have a 10M ohm input, you are not putting any appreciable load on the battery, old analog meters did and I do mean old. So if you are using a modern DVM you are only reading basically the top charge and any load applied to a weak battery would result in its voltage reading dropping.
When testing a battery, 1.5v, 9v, they need a load to determine if they are really good.
FYI: HF has a very cheap DVM that has a function that does exactly that. A different load for each of the 2 voltages that I mentioned. (But no setting for 3v cells, I wish they did). Think of this feature as the same as a load test that would be performed on your 12v lead acid cranking battery but in these small batteries the HF meter just uses a smaller current drain.(I believe it's 4mA for 1.5v cells and 25 mA for the 9v cells).
Remember the battery has to retain its voltage and also produce enough current for the electronics to work.
When you use a modem DVM, most have a 10M ohm input, you are not putting any appreciable load on the battery, old analog meters did and I do mean old. So if you are using a modern DVM you are only reading basically the top charge and any load applied to a weak battery would result in its voltage reading dropping.
