1997 850 T-5 no crank/start, low battery voltage...

[zamador]

OK, I guess reading the directions for the jumpstart/charger unit (it's a Jump-n-Carry JNC660) made me think it should just work immediately when I connected it to the car which I guess isn't the case. I've taken the battery out and am charging it with that same device, should I just wait until the voltage is reading above 12.6V and then try reinstalling and starting? Even though it was showing 19.9V, I'm a bit confused as to how my battery could be dead when the car's electronics were still being powered.

[dj_v70]

The starter needs much more power than other electronics/lights in car. Your battery is too weak. Even if you get it to 12.6v it is possible that it still won’t start the car (75% chance that it will work though). You need power, which includes voltage and current. You might get the voltage but not the current.

[abscate]

I don’t. Think that charge pack has a trickle charge function. You need a 5-10amp charge capability overnight to bring a battery to full charge

When are you reading 19Volts? That is not a good reading , something is going wrong there, too.

[zamador]

I was reading 19.9V directly across the battery terminals with my multimeter, both connected to and disconnected from the car. I'm going to try jumping it with another vehicle but I think it must be a problem with the starter.

[misha]

Is a battery indication turned ON at your multimeter?
It's a 12v battery....when re-charging it must not exceed 15v...19.9v is very WRONG.
Either your multimeter is shot,or you're mistyping this.

[oragex]

I replaced the battery earlier this year
My battery is only at 12.06 volts

How do you measure the battery? It should be measured 30 minutes after driving the car with all computers and every single light off - anything that is on will drain battery current and lower the voltage.

If you measured it properly, you have a problem with the charging system. If all cables check fine (no cracks - even under the red jacket, corrosion, broken ground wires, etc) - I'd first look into the alternator. With such a weak battery you should read a good 14.4V when the engine is running, until the battery is fully charged.

Another possibility is a parasitic drain that's discharging the battery overnight. Measure it 30 min after shutting the engine off, then the next morning, and compare the voltage - there should be no more than 0.1V difference. A parasitic drain will discharge the battery, then the next day it gets charged back again while driving - this battery cycling will kill it in matter of months. A worn battery can no longer charge (no longer get a decent voltage of 12.5 or higher) and no alternator will even manage to charge a worn battery - some alternators will even not put more than 13.5V if the battery is worn and can no more be charged.

To start the car, use the cables and jump the battery from another car with the engine at idle - plug both cables red to red, minus to minus directly on the battery with care not to touch any metal parts with the alligators.

[oragex]

I was reading 19.9V directly across the battery terminals with my multimeter, both connected to and disconnected from the car. I'm going to try jumping it with another vehicle but I think it must be a problem with the starter.

As others mentioned, I think that is physically not possible. Wasn't it rather 9.9V ? That will be a well discharged battery - basically fully discharged. Or maybe the multimeter is kaput?

[zamador]

Oh my God, yes, I was making a stupid typo. Very sorry. I meant 11.94, not 19.94.

I have tried jumping the car with another vehicle and still no noise from the starter solenoid at all (I verified battery voltage was present at the starter nut).

[abscate]

That’s dead. Get it on a real charger for a long day.

[misha]

Try this:
Remove the good known battery from other vehicle and put it in your car.
If it cranks and start...replace it with a new one.
Easy.