[ember1205]

I'm wondering if what I'm seeing is actually normal or not (I don't think it is).

My car is a 2020 2SS that was built in August of 2019. It has been on the dealer lot until I bought it on 6/6/20. It is unregistered and sits in my garage with a whopping 10 miles on it.

I have a 1.5A charger / maintainer (https://www.amazon.com/Schumacher-SC...s%2C182&sr=8-6) that has been used on a variety of different cars, motorcycles, etc.

I did a voltage test on the battery on the car after it had sat in my garage for over a week without being started. It read about 12.2V. Since this is low, I decided to hook up the maintainer.

After being connected for over 12 hours, the charger still shows that it is in the charging state. I removed it from the battery and put the digital meter on the battery again. The voltage showed 13.11, but immediately started to tick down 1/100 at a time, roughly each second.

- What should the fully charged voltage of this battery be?
- How stable should that charge be with a meter connected to check the voltage?
- Is a 1.5A charger going to be sufficient, or is there enough of a parasitic draw that's "baked in" to this car that I should have something with a little more capacity?

My gut tells me that the extended period of sitting on the lot without being started has degraded this battery - especially if the charge dropped off through the winter when actual damage to it could have occurred if it even partially froze as a result of low charge.

Thoughts on this? Should I plan to get it directly in to my local dealer to have the battery checked as soon as I get plates for it? Or, is what I'm seeing actually normal?

Will the conditioner potentially correct this over some small amount of time if I leave it connected long enough?

[Glen e]

Anytime you charge your battery and then immediately take a voltage reading, you are reading up false “surface charge“… Wait a few hours and/or get in and turn on the headlights or some other power drain for 10 seconds then stop, then do your voltage test.

When a battery this big is down on power, a small battery tender might take a couple days to recharge it. Recently on a Camaro batteryThat was mostly drained, it took 36 hours on my small battery tender to bring it up.

[Nothing like an SS]

Battery voltage should be ~12.6. 12.2 is sufficient, but not ideal.

[Rock-It Man]

My Battery Tender Plus, which is a widely used and well regarded device, runs at 1.25 amps or less DC. It's more than adequate to maintain a battery for months at a time.

I kept my first OEM battery lasted 7 years, and the car sat for 6 months every winter. I replaced the battery as a preventative measure.

You battery may indeed be toast from sitting too long. You should insist that the dealer give you a new battery. I expect this might not happen.

But batteries are cheap, so rather than escalating this into a big argument, I would replace the battery anyway.

[Mark114]

I use a Battery Tender Junior on mine during the winter. It only charges at 750mA and kept my Camaro battery charged all winter. Give your charger another day or two. If it still seems low then take it back to let the dealer run a load test and replace if needed.

[ember1205]

Thanks for the input, everyone. I'll check it again tomorrow to see if it still shows as being in a "charging" state or not and go from there. I've noticed no hesitation when cranking, but then again, it's been reasonably warm air temps (65 or better) when I've started it up.

[wjones14]

I have that same maintainer and use it when I store the car during the winter. The charger/maintainer status should go to solid green within a day probably. Mine is always in charging state (yellow light) when I first hook it up, even after driving it 20 minutes to get to my sister-in-law's garage where I store it. When I look the next day, it's green.

[ember1205]

Update:

I let the car sit for another 24 hours (ish) and when I checked the tender, it showed fully charged. I removed the connectors and let everything sit for about a half hour. Battery voltage showed about 12.7 and held there with the meter attached.

I moved the car around to install a new front lip splitter and hooked it all back up to the tender. Half hour later and it still shows as "charging". I'll try and see how long it takes before it hits full charge.

[Glen e]

Originally Posted by ember1205

Update:

I let the car sit for another 24 hours (ish) and when I checked the tender, it showed fully charged. I removed the connectors and let everything sit for about a half hour. Battery voltage showed about 12.7 and held there with the meter attached.

I moved the car around to install a new front lip splitter and hooked it all back up to the tender. Half hour later and it still shows as "charging". I'll try and see how long it takes before it hits full charge.

That’s normal for a battery tender. Anytime you re-hook it up it shows a yellow light… Even on a fully charged battery, but turns green very soon.

[ember1205]

Originally Posted by Glen e

That’s normal for a battery tender. Anytime you re-hook it up it shows a yellow light… Even on a fully charged battery, but turns green very soon.

Yes, I have seen that. It has to go through a sort of "validation" process to be able to determine that it's charged. When I hooked it back up after the voltage test, though, it took 20 minutes or so and never made it back to the charged state. Once I get my plates, I'm going to ask the dealer to load test the battery to ensure that it's ok, but I'm not overly concerned about it at this point.

[Teneck83]

Originally Posted by ember1205

Yes, I have seen that. It has to go through a sort of "validation" process to be able to determine that it's charged. When I hooked it back up after the voltage test, though, it took 20 minutes or so and never made it back to the charged state. Once I get my plates, I'm going to ask the dealer to load test the battery to ensure that it's ok, but I'm not overly concerned about it at this point.

any updates? I have a 2018 with 1,200 miles. Battery dies after sitting for just 30 minutes

[ember1205]

Originally Posted by Teneck83

any updates? I have a 2018 with 1,200 miles. Battery dies after sitting for just 30 minutes

I haven't had mine on the tender for a few weeks now as it gets driven at least every few days. I haven't checked the voltage on it during this time, but it seems to crank just fine.

In an unrelated note, the battery in my '15 Silverado died tonight... Reads 3.6 volts. :'(

[Russell James]

Here is a good home check, no tools or trips to the dealer required... Leave on your maintainer until it is fully charged. My battery tender goes to a green light. Then unhook it for two weeks. After two weeks of not being on a tender... check voltage and try to start. If it cranks really slow and has less than 12V... ie 11.5 and lower. before attempting start... it is either a weak battery or a parasitic drain somewhere. If you come back after two weeks and it is 12+V and cranks normal... all OK. Then just leave the maintainer on it. Be sure to start and drive it a bit once in a while. The worst thing you can do to a car is not drive it. There are just tons of things that need to be used and lubricated, seals, tires....

[ZX-10R]

Optimate6 is the best auto charger n the market - I've tried them all