2nd battery install for plow operation

[Heartbeat Hauler]

My cousin has an old '89 Chevy 1 ton gasser (350 ci) that he uses to plow his trailer court during the winter. Problem is when using the plow it drains his battery down to the point that it won't start the next time. First thing we checked was the alternator. I checked then while it was in for service at his mechanics they checked it and it's good..more or less.

I was wondering if I could add a secondary deep cycle battery, say an Optima Yellow Top, to run just the plow unit and nothing else and then be charged by the alternator. Is this just putting a band-aide on the problem or is this a fix? I really don't want to track down an electrical problem on a truck that old, and beat. Also, any pointers on actually doing this hook-up.

What say you?

 

[CtChevy427]

What size alternator is in the truck?

I once had an 88 F250 that would do the exact same thing with the heavy electrical draw from the plow unit. Day or night it would kill the battery. In the end I went to a shop that specialized in electrical systems and rebuilding alternators. They put on some alternator out of a Probe that had a much higher output. I never had a problem again.

 

[Heartbeat Hauler]

I'm not sure what size the alternator is no doubt whatever was cheap and stock! It probably would be a lot easier to upgrade the alternator than trying to wire in a second battery.

 

[jrkrace]

Bill's right. I would go with the HD alternator. I plowed with 2 single battery trucks before the DMAX and never had a problem. Chances are if the truck didn't have a plow package, you are working with the minimum rated alternator just to power the truck itself.

 

[stacks04]

I read on plowsite.com that napa sells a higher rated alternator like 200 amp one for approx 150 bucks. I was told that at idle it would charge minimally, but 1200 rpm it kicks in fully. Guy was working on a similar truck. I will post the link if I can find it.

 

[stacks04]

Here it is, the only catch is you must upgrade the charging wire to a bigger size cable. Not to bad imo

http://www.plowsite.com/showthread.php?t=109670&highlight=alternator

 

[Heartbeat Hauler]

Thanks for the link Stacks, and the other replies guys. Today I have been reading up on HD alternators. I too am thinking that this truck has the 105 amp alt. The HD alt. are physically larger and I wonder how that will effect the mounting brackets? Gotta be some aftermarket stuff to make it work 'cause I'm sure I ain't the first guy to try this!!

The pic in that thread looked cool, but I don't think that is his 88 GMC, that was way too new of a truck. Like I said the bracketry might be an issue. Also, it was good info about the 2 guage wire, would not have considered that part.

 

[WarWagon]

If it isn't keeping 1 charged 2 is more work.

Alternators are not designed to charge a dead battery. They frequently burn up after a jump start and having to charge the battery.

Be careful around a cold dead battery, they can be frozen. Frozen batteries can explode when jumped.

Take some voltage readings off and then with the truck at idle.
You should have ~12.8V engine off.
Anything over 13.5 with the engine running is good.

Pop off the battery cable and look for a current drain. Is the glove box light or something stupid like a mis-wired radio draining it?

The alt could have gone weak. So good voltage but no power under load.
Test the battery as well - it could bad and not holding a charge.

You should upgrade the ground and charge wire first. By adding a big 3 type of kit like they use for car stereos. Frame to engine ground, battery ground to fender, alt charge post direct to battery. A 200 A fuse on the alt wire is smart...

 

[Heartbeat Hauler]

If it isn't keeping 1 charged 2 is more work.

Alternators are not designed to charge a dead battery. They frequently burn up after a jump start and having to charge the battery.

Be careful around a cold dead battery, they can be frozen. Frozen batteries can explode when jumped.

Take some voltage readings off and then with the truck at idle.
You should have ~12.8V engine off.
Anything over 13.5 with the engine running is good.

Pop off the battery cable and look for a current drain. Is the glove box light or something stupid like a mis-wired radio draining it?

The alt could have gone weak. So good voltage but no power under load.
Test the battery as well - it could bad and not holding a charge.

You should upgrade the ground and charge wire first. By adding a big 3 type of kit like they use for car stereos. Frame to engine ground, battery ground to fender, alt charge post direct to battery. A 200 A fuse on the alt wire is smart...

The battery is new (less than 2 months old). The problem is due to the plow. When running theplow the battery goes dead. Now that I have been reading, I am in agreement that the alt. is the issue not the battery. I am hoping to help him install a HD alt. if we can find one that will fit without a whole lot of modification...the truck is less than pristene....