Had a weird electrical gremlin yesterday regarding the home screen. So I had the car battery checked. It came back good, according to the tech. Voltage measured at 12.49 and 1059 CCA (whatever that is). I'm still suspicious because after being on the CTEK all night, it still registered as charging. So, I'm thinking it's either the battery or something on the car is draining it. Should the CTEK take so long to charge a "good" battery?

 

With ignition OFF for ten or more minutes, battery should have a minimum of 12.6 volts across the terminals when tested with a voltmeter.

 

CCA is cold cranking amps I believe.

 

Chaz,

You've gotta give more deets namely:

1) Model, year engine size na/sc?
2) How long owned?
3) Age of battery?
4) Which model CTEK
5) Any electrical work done recently (dash-cam etc)?

I've a tracker installed in mine, when I can remotely log into and it gives me the (18 month old) battery status, when on CTEK MXS 5 (see I'm specific!) it can reach as high as 14.8v but will soon drop down to closer to 13.5 over time even when still on charge

Appreciate with a badly depleted or old battery it can take 3 days if charging to fully restore

 

Our car has a battery monitor, (BMS) its not very good, none of them are, they are somewhat guessing how much juice is left.
But what our BMS also tries to calculate amount of charge left by how much is going in.
In your case you have bypassed the BMS when you charge it via ctek.
So the battery thinks it has less charge than it actually does- and shuts off the screen.
Also- the BMS must be told/re-taught how much capacity the battery actually has- this is done by the dealer software when he installs a new battery.
You bypassed this when you installed your own battery, as did I. And I get the same gremlin when the battery drops down to 40% or so.