I had a new battery in the car just before it was stored for the winter (Nov-Apr). Went to start it last weekend and as expected, didn't have enough to get her going. I was surprised that after that long it did power on the lights and turn the engine over once or twice before that fatefull clicking starts.

Got a jump and started right up. I drove it around for awhile - mixture of city/highway driving. My question is how long does it take to get fully charged while driving?

That's difficult to say, but depending on how far your battery was discharged, but is still in good chargeable condition, likely an hour drive should do it, especially if it was mostly highway driving.

I don't know if a '76 has an ammeter or voltmeter, but if it has an ammeter it should show a high rate of amps charging until the battery is recharged.

I don't know if a '76 has an ammeter or voltmeter, but if it has an ammeter it should show a high rate of amps charging until the battery is recharged.

Yes - it does. It did show very high (on the + side) for awhile. Then dropped down to the normal position just to the right of center. I'm assuming that just means normal charging going on.

You have it right. It was charging at a high rate until the battery became fully charged. Now it should charge at a normal rate, assuming everything else in the starting and charging system is operating normally.

Gunslinger is right... it would probably take an hour to charge it from the altimeter, but very hard on it,( the altimeter, that is).Better to put a battery charger on it first.