2nd Gen Non-Engine/Transmission Is it the batteries or are there charging problems?

[raxley]

My truck wouldn't start this morning until I ran the charger for a 1/2 hour. Before charging I noticed that one battery was at 12.0 volts and the other was at 12.1 volts. After driving the car for 1/2 hour, I let it sit for about 4 hours. When I came back I checked the voltage and it was 12.2 volts, but it did start.
When the truck is running, my volt-ohm meter is at 13.3 volts, and depressing the accelerator only gets me up to 13.4 volts.
Are any of the above numbers 'out of range'? I was recently just driving a few blocks for groceries, for the last few days and I doubt if the truck was really even totally warmed up. At this point, I'm hoping it's just the fact of not driving the truck enough to replace the starting current, that gave me the hard start condition this morning.
What do most people use for batteries, here? Are the AGM batteries, or the 'Optima' batteries worth their added cost?
I'm hoping it's not time to change the batteries yet, and it's only been 5 years (I'm guessing) since I changed the 'brushes' with Larry B's replacement 'brushes' (I know they are not called 'brushes', but they are made of carbon at least!)

 

[fest3er]

Charge the batteries overnight, then disconnect them and let them sit for a day. If they don't charge up to around 13.5V, have them load tested. If one sags much faster than the other, replace the bad battery.If the system doesn't reach about 14V when running, your alternator is dying. A bench test will probably show that it has one or two bad diodes.Another test: disconnect the + lead from the alternator. If you get sparks when you touch the lead to the post, the alternator is letting current flow from B+ to ground and *definitely* needs to be rebuilt or replaced.I bought a pair of Optima red-tops back around '02. They'd been acting up the past few years. Turns out they were finally failing after 10-12 years of use. They might've lasted longer if the alternator hadn't also been dying and not fully charging them, and had the starter not been drawing 400-600A. Basically, the batteries couldn't produce enough current and the starter couldn't turn the engine fast enough to fire it up when cold. New batteries, then alternator rebuilt locally, then a rebuilt starter from the same shop, and the engine's back to starting up with a ¼-second turn of the key. If I'd had the money and expected the truck to last longer than the Advance Silver batteries I put in early this year, I'd've put red tops in again.

 

[raxley]

Thanks for the information, I'll charge them overnight and see what happens. I replaced the copper connections that Larry B sells, and a couple of other starter things, so at least that part of the 'equation' is good.
Do did you like the 'red tops'? (I guess you did if you are considering/have considered them again) What do they cost roughly?
Thanks again.
Richard

 

[GAmes]

Before you condemn the alternator take the time to see if the battery temp sensor is in spec (spec is in the factory service manual). I buy my Optimas on line. The last set I bought were about $100 a piece cheaper than local prices.

 

[GAmes]

I was paging through the latest issue (93) and there is a blurb about how to test batteries on page 74. Also why it is false economy to only replace one battery in a two battery system.

 

[klcammie]

I bought Walmart batteries 41/2 years ago at 105.00 per batt. They are still good.Check all grounds nad clean if needed. Like GAmes says check batt. sensors that is what the truck uses to charge or not. And he is right if one batt. is bad replace both, or the old one wil cause the new one to over charge.