I took my 2009 freelander out for a drive with my iiD tool attached. I have a new AGR battery.

The voltage reading was 14.2V, but whatever speed I drove at, it would not go higher than 14.3V. Is this something to do with the iiD tool or is there an alternator issue?

Did you use your GAP and also reset the service setting regarding battery change? You should have that option letting the 'vehicle' brain/control module know that there is a new battery. If not, it should relearn the new battery in about 48 hours anyway. I can reset mine in JLR SDD and I am certain you can with the GAP tool.

I did not use the iiDtool to register the new battery. Maybe I should.

RR_BLUE,

The chart that I posted has the information.

Note: to read the chart you need to know what type of battery the ECU thinks you have.

Lets make the following assumptions

1. ECU is configured for a AGM battery

2. you have a AGM battery installed

3. the outside temperature is below 40F

Under these conditions the ECU will request that the Alternator supplies 14.7 Volts until it detects that the battery is almost full and then requests 13.7 Volts.

At idle the Alternator may not be able to generate the 14.7 Volts so the actual Voltage will be lower but at higher RPMs it will be possible and the 14.7 Volts will be present.

We need to know the temperature to help more.

Good luck

Paul

EDIT: if the outside temperature is above 50F then a voltage change at idle to higher RPM from 14.2 Volts --> 14.3 Volts as described should be correct.

Very helpful, and LR say that the starting battery voltage should attain 12.9 volts cranking. In practice it can drop momentarily to 9.0 volts, any lower and the ECU throws a wobbly!