Charging the battery and a gas question

[Evil]

I have a '64 Narrow case.

CHARGING:

The battery is about ten years old... it sat dry for those ten years and I just added electrolyte a month ago. The guy at the battery store said I had a 50/50 chance of it lasting or even working. It had been working great until last week... I was out riding and the bike just up an died. I looked at the headlamp and it was very very dim. I pushed it to a friends and we put the battery on a charger and wthin a few min it started boiling over.

So I am thinking the battery is shot... no big deal I have one ordered. But I want to make sure the battery is charging while I am riding. I started the bike up and put two leads on the battery. It read between 6.14 and 6.2 volts. (headlight off)

That sounds really low to me. Is that normal charge (I had the throttle slightly open but I don't know the rpm)

I don't want to get a new battery and drain it while I am out riding.

GASOLINE
Should I be running high test fuel in this bike?
it has 10:1 compression and is the 5 speed model