Damage from charging battery w/o removing from vehicle?
 

Anyone know how much grief I may have caused myself by recharging a flat battery in 96 XJS with an 8 amp charger without disconnecting battery? Only thing getting juice now is the dash clock!

It would not have caused any problems with the car. But if the battery was dead flat and older the battery may be damaged and not able to provide full current.

Remove the negative terminal and measure the battery voltage, what is it.

W/o negative disconnected I get almost 13 volts. Manual states battery must be removed when charging on a fast charger. I think that is Brit for anything other than a trickle maintainer. Voltage on battery. Battery connected. Nothing gets juice on car except dash clock. No starter solenoid click, no lights, no nothing. I will do my due diligence on battery tomorrow, but something in the system appears fried, and it is not just the battery, I fear.

8 amps isn't a fast charger, and is pretty standard for a consumer grade charger.

Side note: it's better for getting help to not start multiple threads for the same issue.

Good luck

Thanks - not used to forum protocol. Appreciate y’all’s time and input. I've looked at a few other threads that speak of problems jump-starting or charging jags, speaking of the “fragility” of the electrical systems. I agree that my little Schumacher charger doesn’t fit my definition of a fast (actually they use the term “high-speed”) charger, but thought there might be a different usage of the term in Britain, and found the stipulation to remove the battery a bit unusual in any case. Really loving the car, so I hope whatever quirk I seem to have run into has a simple solution. I will continue my journey with this particular problem under this thread. Thanks again.

It could be the battery, even with a good reading. Do you have one you can swap it with? Worth a try, and its where Id start. It may just be toast. I had a similar issue. Mine turned out to be the battery.

If you say 13 volts, that's not bad..."unloaded", so what you need to do is place your meter on the battery ..while...you try to crank, and see if the cranking try will drop the battery voltage, and to what voltage. A healthy battery may only drop to about 10 volts during a normal cranking start. Anything lower that is a bad battery. But as long as you don't even have lights , disturbs me. You should also be able to at least turn your lights on which low beams and side markers should glow with even a low battery. That is the usual test to see if the cranking problem is due to a low battery or a start circuit, meaning if you have a start issue, turn your lights on and see if the lights dim while you are cranking. If they do, your battery is dead. If they don't dim, then you have a start circuit issue, ign switch, solenoid, etc.

The fact that you say there is no lights tells me you are not getting power from the battery to the main fuse panels. If you have you meter, first make sure you have a good ground at the battery cable. The ground cable goes to the right behind the soft close-out fender panel and is bolted to the fender well. Mine was corroded and a little loose. Even if it's tight, remove the bolt holding the terminal end and clean under it and the hardware. Then go to the engine compt and measure at the terminal end of the Pos cable and see if you have the 13 volts that was measured directly at the battery. It's a simple matter of making sure the voltage measured at the battery is getting to the power/fuse panels. There are circuits that are directly connected to the battery, interior lights, side markers, parking, clock and circuits that need to go through the ign switch.
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Thanks, carsnplanes! As suggested by another, I am abandoning this thread and consolidating under my other recent thread on this forum. You guys are absolutely great! Orangeblossom also giving me great info!

Mine stays on a trickle charger year round when not driving.

Yep, Mac does it - I slipped up ...