Hello I have a 2001 Disco II, recently my SRS lite came on, found out that it could be a low battery, so I charged it up with my battery tender, and the tender didnt charge the batt. So I bought a Optima, the light turned off for about a week and a half,now its back on and my battery is low again, now you all are going to say its the alternator, well I got that checked, once I had the new battery in place at a parts shop, they did the test with it still in the truck, and the reading was good, now could this be that the batt was good and fooled the tester. Any advice would be a welcome.

Thank you all for looking.

 

Your alternator is toast, its not putting out enough voltage.
A brand new fully charged battery can mask a bad alternator.
It could also be a loose belt, if the belt is slipping just enough to not charge the battery fully or it is slipping at high rpm to not fully charge the battery your battery will run dead eventually.
Not to mention the added draw of the a/c on your battery.

 

thanks, I thought so, belts are new. pretty soon all the parts on this truck will be brand new, the joys of owning a rover!

 

Buying a new car one piece at a time.

 

Then when you get ALL the new parts, you go back and start over! It's like a perpetual NEW TRUCK!!!

 

Thats exactly how it is.