Battery problems from non-use

[Scott Douglas]

I haven't been driving my car much for the last 4 months. Got hit with some severe vertigo mid-January and I'm finally getting back into things now.
Started my car up twice during that period of time. First time took it out for a short drive but long enough to warm it up good. It started fine on initial start up and any starts I made during that trip. I think I went to the beach so may have started/stopped a couple of times to take pictures.
A week and a half ago I started it but only moved it out of the garage to let it warm up, then back into the garage.
Yesterday I went to go get some things at Goodwill (I won an auction for a train set ) and it wouldn't do anything except show me a few, not all, of the dash lights. Took the wife's car to get the train and came home to start investigating the problem.
Battery measured 6.6V on my trusty VOM. Not good.
I disconnected the positive cable and hooked up my battery charger. It's an old model that turns on when you plug it in. I switched it to the 2 amp setting before plugging it in.
The meter didn't even move when I plugged it in. Switched it to the 8 amp setting and it started out showing less than 4 amps and slowly over the course of the morning/early afternoon showed 6.5 amps. Left it hooked up all day (9:30-4pm) and disconnected it over night. Battery was showing less than 12v when the charger was plugged in and charging at @11am. It finally showed 12.3v at @2pm.
When I disconnected everything at 4:30pm it showed 12.6v.
This morning after sitting overnite disconnected from everything except the neg terminal it shows 12.3v.
The battery has a 2/21 sticker on it so is not new but not old either IMO.
Think I should just pull it and go to wally world to let them test it?

[Rot 911]

I do believe, for whatever reason, that battery is toast. It should’ve held that 12.6 V charge overnight.

[stevej37]

If it will start as is...I would leave it in and drive to Walmart.
I've done it before and they come out to the truck and put a load test on it. If you bought it there, they will switch it out with credit towards the new battery.

I've been happy with their everstart batteries.

[Scott Douglas]

Yeah it's an Everstart alright.
Already got it out an in the CR-V.
I don't like anyone under my hood if I can help it.
Will report back in a few....

[Baz]

The two wear items in my vehicles I have come to believe are the most important to invest in are the tires and the battery.

I will replace either before I get my money's worth, if it means not leaving me stranded on the side of the road.

Even if I have and can change the spare tire - it's still a PITA to do so.

In your case, Scott. Maybe just see if it starts OK each morning for the next couple-few days and go from there.

If it has had a charger on it and is still not performing get another and be done with it.

Glad to hear your veritigo is better now.

[BK911]

Parasitic draw?
Disconnect battery neg wire.
Put multimeter in amp mode.
Jump amp meter across battery to ground.
Record amps

[pwd72s]

You might want to add this to your rollaway. Measures the milliamps of resistance between posts. Also gives a condition report when you punch in the battery's CCA rating. I thought it was too cheap to do what it does,,but bought one anyway. Have had it for a year or so now. By golly, it works..

https://www.harborfreight.com/digital-automotive-battery-analyzer-66892.html

[pwd72s]

Originally Posted by BK911

Parasitic draw?
Disconnect battery neg wire.
Put multimeter in amp mode.
Jump amp meter across battery to ground.
Record amps

another possibility:


https://www.youtube.com/watch?v=KF1gijj03_0&ab_channel=EricTheCarGuy

[craigster59]

I have one of these on the 911 and my truck. A simple turn of the knob when the vehicle is going to sit awhile and no worries. Turn clockwise when you're ready to run again...

https://www.amazon.com/Post-Battery-Master-Disconnect-Switch/dp/B001N729FS/ref=sr_1_34?keywords=battery+disconnect+switch+12v&qid=1649264555&sr=8-34

[Scott Douglas]

OK. Battery checked at wally world and was bad. Don't know how bad as they didn't say. This was the third battery I've exchanged on this receipt so I ended up paying the pro-rated diff based on the 5 year battery I first purchased in 2018. $95 later I've got a new battery that is free replacement for 3 yrs since I paid the pro-rated price. No worries here as $95 won't break the Douglas household.
Now to figure out where the draw is.
I noticed a pretty good spark when I initially hooked up the neg cable, positive already attached. I thought I had everything turned off inside but it appears not to be the case.
I will go back out and try the VOM between the neg cable and post to see how much of a draw there is.
I'm with you Baz, I don't want to be stranded or worse yet my wife be stranded for reasons that could have been prevented with a little bit of foresight or money spent. Tires and batteries are running neck and neck for first place.
New batt measured 12.6v right off the shelf so we'll see.
Now to go check the draw............

[Scott Douglas]

Wow, there's a .78m milliamp draw.
When I have the meter set as shown in the picture.

That's a little high isn't it?

[pwd72s]

Kinda...depends on the car. How many things draw when car is supposedly "off". The newer the car the more the draw. Maybe a dealership could tell you?

[Scott Douglas]

Rather than fight this, I'm going to get one of those master switches.
Thanks for the link @craigster59.

[pwd72s]

a quick & easy solution. In the video I posted "eric the car guy" says with all off, the most you should see is 50 milliamps. You're damned close...possibly within meter error?

[Scott Douglas]

That is what I'd expect. Only thing I've 'added' to the car is a device to defeat the VCM so it doesn't go into ECO mode and drop cylinders. Not sure how much that draws, but it is connected to the positive post so it may be the culprit. I've got sewing machines to service today so have to drop this for now. I might investigate it further when I get the switch and put it on. Should be here Saturday but that's my wife's B-day so who knows what I'll be doing then.

[john70t]

(without googletagmanager or bing javascript being activated, our host website did not return any results..ugg)

Nevertheless:
If you are storing a car for an extended period of time...a battery post cut-off turn switch will help save it.

Natural degradation, radio clock, security features, and other functions will draw amps and drain it down over time.

Most batteries like to be slow charged.
The "smart chargers" add a jolt or three of high voltage to wake it up when it's ready.
Don't use a welder.

[Scott Douglas]

I just looked at the picture I took with my phone of the charger yesterday. It's an old Sears model I've had forever, and I think my dad had it before I got it, so it's pretty old. Once I get it forwarded to my computer I'll post the pic.

[Baz]

Hey Scott-

Thx for the followup!

I have a battery tender on my 356. Even though I run/drive it at least weekly, I still like keeping the battery charged up in between.

Just something to consider.

Oh - I also have one on the 914 which resides over in my Mom's garage.

Not sure if this is feasible for your situation but thought it worth the mention.

[Gogar]

Originally Posted by Scott Douglas

Rather than fight this, I'm going to get one of those master switches.
Thanks for the link @craigster59.

Also a theft deterrent!

[Scott Douglas]

As promised here's my battery charger. Like I said, it's old, but it works.

I hear you @Gogar on the theft deterrent. The car sits in the garage (too much according to my wife) and I don't think I'd open the hood to engage the cutoff if out in public, I'd rather trust the built-in theft system of the car itself.