Most Common Battery Killer

Billysgoat

Billysgoat

The ANTI-BLING!
Joined
Apr 21, 2006
Messages
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OK, just as the title says, what have ya'll found that will kill the batteries? I'm talking overnight or the next day. My truck has started doing it as well as a friend of mine's. I have two fairly new batteries that are correct as to size etc so I know they are not the culprit here.
 
Im in the same boat mine are dying and making it hard to start the truck. Even after i drive it for an hour or two its still hard to start.
 
It's not that hard to check for parasitic drain and start pulling fuses until it stops....
 
I'd say the mysterious "dome light left on" phenomenon is the most common. It is with my wife anyway. :lolly:

Load test each battery with the cables removed. Maybe you have a dead cell.
 
ive seen everything from blower motors to under hood lights causing a drain

best way is to test fuses with a meter
 
If the tops of the batteries are wet, surface voltage can cause parasitic loss. Even if your batteries appear dry you should check them. To check surface voltage, take a volt meter and touch the probes to the top of the battery (on the plastic) near the terminals. I have seen batteries with as much as 8-9 volts of surface discharge, enough to cause a voltage drop over night and make the engine hard to start.
 
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I'd look at chaffed power cables and of course the aforementioned dome light...
 
Good one to check Lee, I will do so.

I haven't had a chance to start pulling fuses, been rather busy the past few days, but that is my next step, I was hoping for some ideas on the first things to check and find it quicker (I'm lazy, and will admit it LOL ).
 
Gives me a few options to try as well.. A friend just called me *****ing about this today. He has a ton of aftermarket crap wired into his truck. But swears he has recently wired everything to switches. It use to be a couple weeks that it would drain the battery, then days, now it has a tough time starting when sitting over night.
 
easiest way to check disconnect ur neg terminal and hook a test light in series if it lights you have a drain start pullin fuses
 
Mine just started doing this after I had to replace a vp44. Never had a problem until this.
Mine is fine if I start it about every three days, but if it goes any longer, it will not start.
The batteries will be dead enough that the power locks will not open with the key fob.
I have a good electric battery charger and noticed that it errored and hinted at a sulfated cell in the battery.
Need to have them load tested and replaced, I guess.
 
I just had one battery replaced and the other load tested, so they are known good. The only things aftermarket wired in are the comp box, mag light charger and window jumper. Everything else I ran from the batteries themselves.
 
Billysgoat said:
Everything else I ran from the batteries themselves.
Click to expand...

ding ding ding, if they are hooked straight up to the battery, there is no way to test if one or the other is drawing current

disconnect them one at a time maybe? or pull the fuses out if they have inline fuse holders
 
Billysgoat said:
I just had one battery replaced and the other load tested, so they are known good. The only things aftermarket wired in are the comp box, mag light charger and window jumper. Everything else I ran from the batteries themselves.
Click to expand...

This brings up another interesting point. Is the battery that you replaced exactly the same CA/CCA as the one that did not get replace? For example, if you put a 750CCA battery and an 850CCA battery in parallel the higher amp battery continually tries to equalize amperage with the lower amp battery and both will fail sooner.
 
Lee is right... The batteries need to be as equally matched as possible and should ALWAYS be replaced in pairs or they will equalize each other and discharge eachother...

Even when purchasing the same make and model battery it is best to try and get them from the same production batch...
 
I agree, matched sets of batteries, changed out at the same time. They try to equalize their charge and the newer one will drain itself trying to charge the older battery. I put the "leftover" good battery in a tractor. There is always Craigslist to get rid of a good but not matched battery.
 
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