I'm having a weird battery/parasitic drain issue that I wanted to share with you guys.

My 97 had a interstate (costco) battery in it for about 7 years. Last year in winter (live in Wisconsin), I noticed when it was very cold out (10F or lower) it was cranking much slower than it used to. I assumed the battery was just getting old and I would probably have to replace it next year.

Fast forward to this winter. When we had the artic ice bomb storm thingy happen, I tried starting the truck and it would just click and not turn over.

A couple weeks ago I decided to install a new battery in it (AC delco 24F battery). The old interstate battery was measuring just over 10 volts so I assumed it finally gave up the ghost.

When I installed the new battery, I also cleaned up cables and connections which were all in pretty good shape still.

I go to start the truck and.....it still cranks over slowly but starts. Weird. I assumed maybe the new battery was on the shelf for awhile and just needed to be charged up. Drove it around for 20 minutes or so, parked, turned it off and turned it back on. Fired right up.

A couple days later I go to start the truck again and it's cranking slowly again but it did start up. I shut it off right away and checked the voltage and it was back down into the 10.5v range.

Now I'm starting to think that not only did I have an old battery but something must be staying on because a new battery shouldn't be dropping below 12v in a couple days.

I get the volt meter out and do an amp draw test and at first, it was drawing 60 milliamps. I noticed that my ultra gauge was in the "scanning" mode, probably what it does when it gets connected for the first time. Unfortunately, the ultra gauge does not leave the scanning mode until the vehicle is started and it fully connects.

I decided to unplug the ultra gauge and see what kind of draw there was from the system with ultragauge removed. There is only 10 milliamps of draw which should never drain a new battery in a couple days.

Now I am thinking that maybe the ultragauge is drawing a lot more power than it's supposed to (not going into sleep mode or something) so I test it.

The ultragauge screen does turn off after the vehicle has been turned off. I have no way to know how many amps it draws when the vehicle is off because everytime I disconnect the battery to test for amp draw, it goes back into that "scanning" mode with the screen on and I'm seeing the 60 milliamp draw.

Ultragauge on there website claims that it won't drain the battery unless it's sitting for like a 100 days without being started.

I should add that I've had the ultragauge for many years and it never once drained the battery. My 3rd gen is not my DD but it usually gets run ever week or two at a minimum.

This has been a long post so let me summarize where I'm at:

1. Even the brand new battery, when installed, the truck cranked over slowly. Unfortunately, I didn't check the voltage of the new battery before it was installed.

2. It's possible that I purchased a bad new battery

3. The truck has been sitting without being started and the ultragauge disconnect for a few days now. I charged the battery back up from the last time it dropped below 11v.

4. Yesterday when I checked the voltage, it was 12.56v. This morning before I left for work it was down to 12.4 volts.

5. I'll check it again when I get home to see where it's at.


What do you guys think? Did I buy a bad new battery? Ultragauge the problem? Something else is an issue even though the system is only drawing 10 milliamps with the ultragauge disconnected?

Any help or insight is appreciated. This one has me baffled.

60mA is not going to drain your battery in a few days. As that's in the range of our current draw rigs in deep sleep.

How hold is your alt? Is it charging properly?

When running off idle, is your voltage above 13.8v?

Also, what's your ambient temperatures? If you're going into the lower Temps, the lead acid chemical reaction isn't as efficient, and the CCA will drop slightly do to that.

Could be a few things. As your thought process is looking good.

Possible iffy battery, alternator not working properly.




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40ma or lower is the factory spec and you being at 10ma is aok.

A fully charged battery in the winter is not 12.7v it’s more like 12.4v depending on ambient temp.

My Saturn sitting 3 days will read 12.3-12.4 this time of year.

Can you measure starter amp draw?

Like mentioned above is your voltage in the normal range?


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This morning when I checked the voltage, it was about 30 degrees outside. Alternator is original but is charging just fine, usually the truck is at 14.1v - 14.3v while its running.

I don't have a way to measure starter amp draw as my cheapy multi meter only reads up to 10amps.

I'll check the voltage again after to work to see if it's dropped even more. The fact that the new battery was cranking it over slowly makes me think I may have gotten a bad battery.

I should add, I put new contacts in the starter and I can't remember what I did to the original alternator a couple years ago. I believe I installed new "contacts" in the alternator also? It wasn't giving me issues but I had the engine out (for a different reason) so I was "refreshing" a bunch of stuff while it was out.

All batteries have a manufactured date on them. Most are open coded, some aren't. Never buy a battery that's more than 3 months old. I prefer that it be no older than 1 month old. You can Google the date code based on the brand name.

If the battery is the type where you can open the caps to add water, put a hydrometer in each cell and check the specific gravity. Sounds like you have a bad cell and should be covered by warranty. Take it back where you bought it and ask for another one.

Try cleaning all ground joints frame and body. I bet your area uses salt and the ground wire at the engine block (below the alternator) may have a poor connection. Also, do you have OEM terminal?
If you have a weak starter relay, it may not fully engage the starter plunger.
Usually weak starter contacts start showing it's symptoms in the colder months. That's how I know the contacts are getting weaker. Oh.. do the power windows roll up at the same speed as before? If it is slow, then it is a bad battery.

Yes, some times a new battery may last few days. Try getting it tested.

Your starter could need regreased. What’s your battery voltage during cranking?

A few months ago a member had slow crank and it was his starter. I think his starter was pulling 300a or so. I did the amp draw test cranking mine over with the fuel relay pulled and I think 160a ish was what it pulled.

Edit: I found it. It started out at 190a and went down to 130a and leveled out shame you can’t borrow a DC clamp on amp meter.


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I just checked the voltage when I got home. It dropped to 11.5 volts. Rechecked the amp draw (no ultra gauge plugged in) and it's still 10 milliamps.

At this point, it's got to be a bad battery right? I believe I could take the battery out of the car entirely, charge it up and in a few days, it will be down on voltage.

Again, it cranked super slow when I installed it and it should have been charged up.

The starter cranks perfectly fine when the battery is charged and at the proper voltage.

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Would dirty grounds cause the battery voltage to drop though over a couple days? I know poor grounds can cause the starter to not crank at full capacity.

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I pulled my hair out chasing that and it ended up being a shitty battery.


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That's easy to check. Pull the terminal off let the Battery set overnight. If it goes down from 12.8 to 11 something. I would agree it's most likely a bad battery.

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That's what I'm doing tonight. It was at 11.5v so I disconnected the battery all together. If tomorrow it's significantly lower, case close. Shit battery.

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Lead acid 12 volt battery are flat at 12volts... Anything below 12 volts is bad and 10.5 volts is extremely bad. Fully charged around 12.6 volt. Sometimes will float a little higher but 12.6 or 12.7 is considered fully charged.

I checked the voltage again this morning, it's been disconnected from the vehicle over night and it's dropped down to 10.3v

Case closed, bad battery. I'll have to exchange it this weekend. This time, I'll bring my volt meter with so I can check the batteries on the shelf to make sure the one I pick is fully charged.

Thanks everyone

Weird parasitic draw solved found to be all the idiots in D.C. running the country into the ground.

Glad you got your issue resolved. :TU