I have just bought a Bosch 049 battery to replace the battery in my Plus 8. This is a 45AH battery rated at 330 cranking Amps.
I put a battery tester on it and go the following:
Charge 100%. 12.82V
Health 78%. CCA 292A
Internal R. 10.27 milliOhm
I've no idea how the tester works, but I would speculate it infers the state of charge from the open circuit voltage (12.82V) and it measures the internal resistance by putting the battery briefly under load (maybe 100A ?). No idea how it measures the CCA. Nor any idea of how the health number is calculated.
But anyway, 10 milliOhms seems a bit high for a brand new battery. I've seen values of 5-8 millOhms for other new batteries of similar size and technology.
Does anyone know anything about what is an acceptable. value for internal resistance of such batteries?
I don't see a date of manufacture on it, so I've no idea how long it has been sitting in store, so I'm wondering if the battery has simply degraded over time before I got it.
