Straight from the OPTIMA website:
"Fully-charged, our REDTOP batteries (and 34M BLUETOP) will measure about 12.6-12.8 volts and our YELLOWTOP and BLUETOP (except the 34M) batteries will measure about 13.0-13.2 volts. Each manufacturer will generally indicate a range or minimum voltage level for a fully-charged battery. If you are measuring the voltage on another brand of battery and don't know what the fully-charged voltage level should be, it is safe to assume it should be at least around 12.6 volts. - See more at: http://www.optimabatteries.com/en-us....lp6sBJ4H.dpuf "

 

One extremely important point that Cambo made is that any assessment needs to be measured directly at the battery.

There are constantly changing voltage drops in the wiring of a modern vehicle as various subsystems switch on and off.

Even over OBDII, the voltage is not monitored directly at the battery on the vast majority of vehicles. These reading will lead to false conclusions. This issue is often even more exaggerated on Jaguars with the battery location in the boot leading to longer cable runs.

Think of it this way. Voltage is like water pressure. If you want to know the water pressure entering the house, and you have two bathrooms with showers, you do not run one shower and check the pressure at the other shower....you instead check the pressure where it enters the house.

 

While I agree that battery assessment is ideally done at the battery posts,
I am in disagreement with the assertions about significant voltage drops.

If I find a voltage drop of more that tens of millivolts, round trip, I am going to
want to know why and rectify the cause.

 

OK just a little more info. Left the car overnight with out the smart charger hooked up. I opened the trunk and using my digital multi-meter took a reading at the bat. + and the ground in the left panel. Reading was 12.52 volts. I started the car and during open loop idle around 1200 rpm the meter read 13.68 volts. Just some more data.

 

Best deal for tracking voltage......great reviews...works like a champ.



Buy one for each car they are so cheap. Leave in glove box.

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