Battery or charging system

Have a B2600i. Last 2 weeks, I had to charge the batter for 20 minutes before I can starts the truck. Drove for 10 minutes. Sat for a day and the next morning it won't start. Charged again and it starts without problem. took it the Les Schwab turned off the car. It wouldn't start unless from a jump. and they told me it was a bad battery. (9 years old) I was wondering, if I can charge the battery at home and it starts, why wouldn't starts again after drove it for 25 minutes? Is my alternator going bad too?

Charge up you battery at home so the truck can start. Measure the voltage across the battery terminals with the engine running, and with the engine off. The voltage should be 2 volts higher with the engine running if your charging system is OK. Does your charging light/check engine light stay on while the engine runs? Those are pretty reliable....my experience is more often it's the battery.

Thanks Cusser. I assume I needed a voltage meter to test my battery. Don't know how to use one but I am sure it's not to hard. Do I clamp on the battery - and + terminal itself or the terminal cable?

Either; as long as the cable terminals are clean and making good connections tothe battery. Most put the positive on the cable positive terminal (first) and the negative to some bare metal of the truck (second) so that if a momentary spark occurs it will be physically away from the battery, eliminating any chance of a hydrogen battery explosion. When done, remove the negative lead first. A simple digital voltmeter is available at Sears for under $25, and they frequently go on sale there for $9.99. I have two of theirs.

Thanks for the info Cusser

My 88 had the same problem. Turned out to be the blinker/dimmer switch.
Those cables HAVE to be clean. The slightest amount of oxidation on them makes my truck moody. Hope I helped.