Although prices have improved a little since the height of COVID, a Deka replacement for this battery still runs about $550-600 + tax in my market. Winter is coming, and I'm wondering if I *really* need that replacement just yet or if this is one of those cases where a well maintained AGM battery lasts a very long time. Curious WWYD.
Application: BMW F10, dealer warranty replacement battery PN 61212353812, AGM 92AH 850CCA group 49, installed in 2015.
The vehicle overnights in my garage 99% of the time. I have a wall mounted CTEK MXS which gets connected overnight often. The vehicle itself reports that most of its life the battery SoC is >80%, and has never dipped below 60% for any length of time. I do not have an auto start/stop function.
If I top up most of the way with the CTEK, give it a couple of hours and a bit of load to remove surface charge, my Solar BA9 says 12.71V 725-730CCA @ ~70F
Yes, this battery owes me nothing. It's 7 years old. But, $600? Discard something perfectly useful? Because the BA9 is fairly new to me, I don't have readings from when the battery was new. By my math this battery calculates out to a SoH of ~85%. But for all I know it would have read 1000CCA on the BA9 when it was new, making it more like 70% SoH. Assuming the BA9's testing method can really be trusted...
I used the cranking test on the BA9 earlier today as well. If I read it right it stayed above 12V during cranking. I might play with that a little more to be certain. Last November with this battery I performed a maintenance procedure that required oil system priming. It cranked the engine for 60s over a couple of minutes (cool down breaks) with full compression (plugs in, injectors disconnected) and I think it held 11 or better the whole time.
Application: BMW F10, dealer warranty replacement battery PN 61212353812, AGM 92AH 850CCA group 49, installed in 2015.
The vehicle overnights in my garage 99% of the time. I have a wall mounted CTEK MXS which gets connected overnight often. The vehicle itself reports that most of its life the battery SoC is >80%, and has never dipped below 60% for any length of time. I do not have an auto start/stop function.
If I top up most of the way with the CTEK, give it a couple of hours and a bit of load to remove surface charge, my Solar BA9 says 12.71V 725-730CCA @ ~70F
Yes, this battery owes me nothing. It's 7 years old. But, $600? Discard something perfectly useful? Because the BA9 is fairly new to me, I don't have readings from when the battery was new. By my math this battery calculates out to a SoH of ~85%. But for all I know it would have read 1000CCA on the BA9 when it was new, making it more like 70% SoH. Assuming the BA9's testing method can really be trusted...
I used the cranking test on the BA9 earlier today as well. If I read it right it stayed above 12V during cranking. I might play with that a little more to be certain. Last November with this battery I performed a maintenance procedure that required oil system priming. It cranked the engine for 60s over a couple of minutes (cool down breaks) with full compression (plugs in, injectors disconnected) and I think it held 11 or better the whole time.