Safe to trickle charge batteries all winter?

[AngryScientist]

Probably an over-thinker question:

I have a few things I dont use in the winter. A car, a motorcycle, a lawn tractor and a camper deep-cycle marine battery.

Do we feel it's safe and not a fire hazard to just leave all of these on a trickle charger in a cold garage all winter? Two are AGM batteries, two are flooded lead-acid.

My gut says of course this is fine, but sometimes a nagging concern will sneak into my head that this could be [a remote possibility] of a fire hazard.

Talk me off the ledge?

 

[dnewton3]

If you have a "smart" battery charger, then the answer is yes; absolutely.

For example, I have used Battery Tender brand products for almost two decades; everything I own is on a BT charger except for my daily drivers.

If you don't think they are worthwhile, I'll let you know that I just replaced a 19 year old battery on my Kubota L3430 tractor; the OE battery lasted from 2006 to 2025, on a BT charger. NINETEEN YEARS !!!

 

[JavierH19]

You could but I'm always weary they'll fail then overcharge. I plugged mine back in every 2-3 weeks and unplugged it the next day.

 

[JavierH19]

If you have a "smart" battery charger, then the answer is yes; absolutely.

For example, I have used Battery Tender brand products for almost two decades; everything I own is on a BT charger except for my daily drivers.

If you don't think they are worthwhile, I'll let you know that I just replaced a 19 year old battery on my Kubota L3430 tractor; the OE battery lasted from 2006 to 2025, on a BT charger. NINETEEN YEARS !!!

19 years out of a battery is wild to imagine.

 

[MNgopher]

Its fine to leave them plugged in. Currently running an 11 year old AGM battery as my boat starting/radio/electronics unit. Have a Gel Cel deep cycle that is 18 years old that still works (with diminished capacity). (its on backup duty now)

 

[johnmyster]

If you don't trust the charger...

I've left my house before for extended work assignments. I'll put the charger on a timer plug that is programmed to run a couple hours a week.

Alternatively, get a charger that you can trust. But it's nice to know you have a redundant backup against bad things happening.

 

[TCL]

I got 13 years out of my original 2000 John Deere LX255 lawn tractor battery ( same size as a Honda Accord) it was still working. Never used a battery maintainer. Sits in shed all winter. I'm located in Southern NJ.
Bought a new JD battery in 2013 and it still going.
Two batteries in 25 years.

 

[PF52]

I have a couple cars that stay in the garage all winter, not driven. I'll put one on the trickle charger for a week, then move it to the other one. Then I'll leave the charger off for a week or two before starting the process all over. Winter's just about over by the time I go through three rounds and I never feel like I've over-charged anything.

 

[crashz]

I leave my dump truck and wife's Beetle on a maintainer all winter. Every other battery not used is brought into the house. No issues with any of them.

 

[SwampSurvivor]

I bought a handful of the cheap harbor freight battery maintainers. I think I have $70 into them buying them on sale. So far they have saved me at least $100 because I didn't have a battery die in an unused vehicle over the winter. I ran extension cords out to the Sentra, F-350 and Cherokee this winter. The generator, two mowers and ATV were in either the garage or shed hooked up to them all winter.

Picked up another one for the newest Jeep. I think this winter I'm going to pull the batteries out of the Jeeps and park them out at the back side of the yard and leave the batteries in the garage for the winter.

 

[We're Metals]

Regardless of battery tender use, they just dont make batteries like they used to. I'm only getting 3-4 years from batteries no matter what I do. Ive got 10 vehicles.

 

[Pablo]

I need to fire up my genny. It's been on the smart charger a good while. We will see!

 

[SwampSurvivor]

I bought a handful of the cheap harbor freight battery maintainers. I think I have $70 into them buying them on sale. So far they have saved me at least $100 because I didn't have a battery die in an unused vehicle over the winter. I ran extension cords out to the Sentra, F-350 and Cherokee this winter. The generator, two mowers and ATV were in either the garage or shed hooked up to them all winter.

Picked up another one for the newest Jeep. I think this winter I'm going to pull the batteries out of the Jeeps and park them out at the back side of the yard and leave the batteries in the garage for the winter.

Last fall I put the used 2019 battery from my Grand Marquis in my truck to replace a battery from 2015. It still worked but not sure how. It did die a few times but that is because my brake controller drains the battery and I forgot to unhook it after towing.

I put batteries in my Cherokee in 2020 and 2024. I had one explode while charging. I wasn't around to hear that but came back and there was acid running on the ground and the case cracked.

 

[JeffKeryk]

Yeah, get a decent battery tender. Costco has 'em sometimes and Amazon runs sales.
And yeah, it's better than a dead battery.

Good luck.

 

[mrsilv04]

I would buy one quality and highly rated 1 amp smart charger, and leave it on each battery for a week at a time.... so each battery would be on the charger for one week each month.

https://www.amazon.com/NOCO-GENIUS1-Fully-Automatic-Temperature-Compensation/dp/B07W46BX31

 

[CT Rob]

Battery in my moms 2015 Crosstrek is the original battery. Been on a battery tender almost its whole life ,atleast 75% of it. Probably helps that its garaged as well. Just turned over 5000 miles a month ago lol.

 

[wwillson]

If you don't think they are worthwhile, I'll let you know that I just replaced a 19 year old battery on my Kubota L3430 tractor; the OE battery lasted from 2006 to 2025, on a BT charger. NINETEEN YEARS !!!

You must have talked very nicely to that battery.

 

[Nick1994]

Yup, my sand-rail sits on a Noco battery charger all the time, year-round. Has a small AGM battery.

So does my aunt’s 1970 Beetle. It’s got a regular lead acid battery.

 

[SonofaBoomer]

Got 3 years with my battery tender 1.25A on my lawnmower battery so far.

 

[50yr Street Mech]

Had problems with cheap tenders over charging & bubbling out the electrolyte. Switched to a bunch of Noco 2 Genius tenders. Put out a steady 12.2 volts. No bubbling. No worries. Have one battery for my Kohler 20 RESA generator on a Noco for 6 years ( back up battery). All cells are fine. Never added electrolyte either.