Battery Discharging HELP


Old 11-29-08, 04:07 AM
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Battery Discharging HELP

I have a 89 Full sized Blazer, I just put a brand new battery in it.
(use it for plowing)

The battery is isolated from the car with a continuous voltage
solenoid, with the negative side going to the solenoid, and a toggle switch on the inside which activates the battery for starting the car, and running anything. (at first I thought it was the alarm system built into the car, which is why I installed the solenoid)

Something is drawing the power down on the battery since it was low enough where it would not crank the car over after sitting for 2 weeks.

Is it possible that the alternator could be drawing down the power? Or could the cold weather be bringing it down that much?
Old 11-29-08, 04:46 AM
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How does the battery receive its charge? Is it in line with the main battery or is it hooked directly to the alternator? It is possible the battery is doing its job over and over, but not being recharged during your operation. Just an idea.
Old 11-29-08, 06:32 AM
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First I do not know what a continuous voltage solenoid is.
But from your description I picture this.
You have a new battery in a Ford which gave problems in the past with dead batteries.
So you put a solenoid in series with the negative high amperage cable. Just like the positive high amperage cable has a solenoid for starting the vehicle.
And you have a toggle switch to close the solenoid when needed.
Sorry if my mental picture is wrong and please correct me if I am wrong and fill me in on what a continuous voltage solenoid is. I am guessing you are referring to it as continuous voltage because after you got the vehicle running you would have to leave the power to it on to have the negative wire circuit closed.

I cant see the battery being new getting that low because of cold weather. With the negative wire open with the solenoid I cant see a problem with the alternator drawing it down. How could it it there is no closed circuit?

Lets move on the the truck. Is there a lot of resistance from the engine when cranking it?
I have a inductive amp meter which I carry in my glove box,
It costs about $15
Could you get one and test how many amps the truck is drawing when trying to start. It the engine is extremely tight when cold then it would draw down any battery.

I am assuming that you know that the charging system is good and this only happens after the truck sits any length of time.
Old 11-29-08, 08:21 AM
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A continuous solenoid is like what is on a electric golf cart. Made for using with continuous voltage, unlike the kind on a starter which is only made for short periods.

The alternator is hooked directly to the positive cable on the battery. It is putting 14.5v in when the Chevy Blazer is running, which means to me that the system is charging.

Yes, it seems to only occur after sitting for any length of time.

I did have a solar charger hooked to it, but just ripped it out thinking the rectifier in it might be bad and pulling the battery down.

Guess, I'm going to have to put a load tester on the battery, and see if maybe the new battery is bad. (possibility)

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