batteries dead after sitting 2 weeks with newer diehard platnums

[hrc200x]

2002 F250 7.3 auto 121k miles, edge evolution, 4" exhaust, AIS intake

A little history, bought truck almost a year ago in the middle of winter. Came with one new napa battery and a motorcraft (I'm assuming the original). Truck only gets driven on weekends, if that. If it got drove weekly it started fine. Truck happened to sit 3 weeks in fairly cold MN temps, single digits...wouldn't start. Found out the new napa battery was froze. Got a new for free since it was still under warrently and when I threw the motocraft out of the truck it cracked when it hit the ground (little frustration was involved)...good excuse to buy new batteries. Not wanting to mess around with junk I bought two new Diehard Platnums. Started fine the rest of the winter on them but I can't recall if it ever sat for 3 weeks. Started fine all summer.

Fastforward to today:

Truck has been sitting not being started in 2 or 3 weeks, week ago we had 40 degree temps few days ago it was in the single digits. Try to start truck and it just clicks. Notice frost on the passenger side battery (guessing its froze), pull it out and put the newer NAPA battery from the first paragraph in. Truck starts. Let it run a bit, shut it off, unhook the napa battery and leave the diehard hooked up on the driver side and try to start truck, it only clicks so alteast it had power and not froze also. I couldn't hear water in either diehard battery so either they are both froze/almost froze or there is no room for the water to slosh around in diehard platnums?

Last year I tried a test where I unhooked one battery completly, put a meter set to miliamps between the NEG battery post and the NEG battery cable on the battery thats still hooked up and watched what happened. The number seemed high at first but after 30 or so seconds would drop, then 50 seconds drop again. At which point it would be at a number close to what other vehicles I was trying the same test on would be.

Open to suggestions. Thanks.

[Stroked68]

Bad battery connections or you got some bad batteries?

[hrc200x]

connections at the battery are very clean and very well greased. They came greased from the guy I bought it from which makes me think he had a similar problem... maybe the reason truck was sold. Maybe one of the platnums went bad in the last couple weeks. I'll have to find a load tester and see. Anyone else running platnums that can check and see if you can hear water in them?

[Stroked68]

Getting a new bad battery isnt unheard of. Sitting on the shelf will kill them but not very likely. Or you could have another prob that shorted it out or somethin. Alternator workin properly?? I deleted my Air Intake Heater (AIH Delete) cause the solenoid stuck and drained my batteries within 15min. Wouldnt even turn the cab lights on.

[hrc200x]

How did you trace it to the AIH solenoid? The platnum batteries have been in truck for 8-10 months. I wish my bats would drain in 15 min. Waiting 3 weeks before they go dead makes it hard to troubleshoot.

[iracemine]

Sounds like a parasitic draw. If I remember correctly on these trucks its typically the alternator.

[hrc200x]

Any advice on how to find the problem? Thought the test I did with the multimeter would show a abnormal draw, unless the draw gets worse after it sits a couple hours/days. May have to leave a meter hooked up for a days at a time and see if the draw gets worse.

I had a alt. in a small car drain the battery but it would do it over night.

[RSG]

First off--repeatedly draining the batteries will kill them. So at this point you may have 2 problems, the original (which might be a bad battery to begin with) and the now-likely bad batteries. I assume you are slow-charging them back up after a discharge? If you are only slamming them with 10+Amps for awhile, that's not going to cut it. If they were discharged their freeze-point raises and they freeze easier.

If it was me I'd pull them both, have them load tested, and if either is questionable, replace both. Since your 'vested' in copper-tops maybe they have a warranty? Ford is running a Moto-craft sale on theirs' for around $110 each and they aren't junk. But I got 2 new off-brand for $65 each.

Oh, to directly answer your question on sloshing? Pull 'em both, bring indoors to warm, and then you will have your answer? While they're warm trickle/maintenance charge them for a day or three.

I use this charger/desulphator system for all our batteries. Works for our varied battery demands.

Good luck!

[Stroked68]

Well luckily when i found it was my AIH, it was dark out and in the parkinglot I popped the hood and the AIH heater was glowing red hot since it was on all the time. Thats how I found it. Its just one area of these trucks that gives probs. It doesnt get cold enough around here for me to justify puttin a new solenoid on it. If it gets too cold I just plug her in.
I agree with RSG on the batts. Trickle chargem and keep the warm. Dead, cold batteries arnt good. Could be a stereo system too. I've seen people hook them up wrong and they slowly drain batteries over time.

[hrc200x]

Will have to run into town and have NAPA load test them, closest sears that sells diehard is 100 miles away.

About the testing to see if I can hear water in them...I don't know if these batteries are so full of water that there is no sloshing room, was hoping someone with platnums could do the test and see. The one die hard that had some juice left in it didn't make a sloshing noise, so don't know if its froze (wouldn't think so as it had some power), or almost dead but still in liquid form with no sloshing room.

These have a 48 month warrenty, and I just happen to be going to sears this thursday.

Radio in this truck is stock.