What should I expect the battery voltage to be running and off to ensure everything works?
What is the best cold cranking amp for an LR3 battery?

 

Off you want no less than 12.3v. Any lower and you might get startup faults. 12.5 is ideal. Running you want no less than 13v. I consider 13.2v to really be the minimal and generally expect to see 13.6 to 14.5. After cold starts, 14.1 or 14.2 is the most common voltage I see until things warm up. Ideally you want 800 or more CCA, 950 is ideal especially in cold climates. I think spec is Group 95R and today I think most 95R will be at least 850 CCA.

 

DakotaTraveler's voltage figures sound right to me. A few weeks ago I started to see more of the mid 13s versus the 13.6-14.5 range and then shortly thereafter started throwing the battery warning on the instrument cluster. Just replaced the alternator, and am back up to 14s in regular driving.

 

Thanks guys I will get that checked later today.
I mentioned in another thread that when I was driving the AC cut off, thinking it may be an overheat I switched off the engine. Turned the key to start and all lights were on the dash but the starter didn't turn. After a few minutes the AC starts blowing and the engine started.
The battery is a 650 CCA so may be a problem, also here in the desert even good brand batteries barely last a year and a half.

 

If there is a problem with HVAC module would this stop the from starting?

 

That's a solid maybe. I can't remember for sure, but when I had to replace my climate module, I seem to remember disconnecting the module having a similar effect of a bad cluster, bad brake light switch, etc. I believe the climate module is looped into the network and breaking the loop anywhere throws it into a tizzy!

 

I’m going to add a minor correction. A proper automotive battery should read 12.6v, following a rest overnight and the engine not running nor have been started. (resting battery)
A battery that reads 12.3v contains less than 40% of the specified CCA capacity and is not sufficient nor useful.
The generator dynamically supplies charging voltage when the engine is running. Thus the variable output up to 14.3v.
Our vehicles demand a properly functioning battery. With the many electronic components, some will not even start up if the available power is not sufficient. (P=I*E)

Please see: https://batteryworld.varta-automotiv...ttery-test-car

Cheers!

 

Wow... google... cute. I prefer reality knowing not everyone runs perfectly brand new batteries all the time.

 

Interesting response. I thought it necessary to provide an accurate correction to common misinformation...
(Equally, this very information is included in the updated JLR Workshop Manuals.)

Actually Varta is the world's largest battery manufacturer and OEM provider to most of the upper echelon automobile manufacturers.
And FWIW, I prefer to not waste time continually charging the battery and dealing with failing systems as opposed to just swapping it out once it cannot maintain a charge at 12.4 v. Others may have different ideas or opinions, but that deviates from the best practice and the science.

Cheers!

 

Well checked the battery which whilst not perfect seems not to be the problem as the vehicle started once it decided it was ready to start. However hazards started and a bunch of faults showed up up on the dash.
I am going to have to get the HVAC module looked at as the AC cuts out then the vehicle will not start until the blower starts.