I have a 2023 CX-9 that I need to store for 5 weeks including all of February. The car will be in an unheated garage and I expect the temperature in the garage will range from 20F to 35F.
1. I can simply park it and hope the battery does not discharge, freeze, and possible crack the case.
2. I can disconnect the battery, it should then hold enough charge to be OK but I don't know if the car has any 'backup' type batteries that may be damaged or if no power for 35 days will mess up any electronics.
3. I have a .5A motorcycle charger I can hook up, should keep everything good, but I really don't like leaving a questionable item like that plugged in for 5 weeks without anyone to keep an eye on it.
4. ???
Anybody have any suggestions on how to handle this situation.

 

Option 2


Option 1 ...why take the chance. *But...
Option 3... not unless it is a automatic charger like a quality NOCO.
Option 4.. there really isn't any that are safe or reliable.

*If the battery was load tested prior to your storing it technically you should be able to just p[ark it and it will not discharge in 5 weeks. But to be sure disconnecting is a better option. You will only possibly lose some preset amenities but nothing drive related.

 

Thanks for your advice. The charger is made in China and has automatic sensing circuitry. If the power goes out this thing might forget it was set to motorcycle at .5A and go into its 10A mode and that could cause a serious problem over 5 weeks.
If I only risk some presets buy pulling a battery cable it's the safest bet, besides the hard reset will maybe do it some good.
If you think of any downsides let me know, otherwise thanks again.

 

I would not use that charger.
Disconnecting the ground will not affect the current ECU adaption. They remain unchanged until you drive again. You may only lose some pre-set manual settings which are all easy enough to reset.

Overall disconnecting the battery is the safest insurance not to have a problem.

 

A fully charged lead acid battery freezes at about -80°F. A discharged battery will freeze easily. Every battery has a very slow rate of self discharge. When connected to the car there are always some electronics making a small draw from the battery. As stated, disconnecting the ground cable is safe and easy. Once the ground cable is off there is no need to remove the positive cable.

By the way, when disconnecting a battery to lift it out always disconnect the ground cable first, and always reconnect the ground cable last. When using a wrench on the positive cable clamp if you touch metal of the car and the negative (ground) cable is attached you'll get a big spark. If the negative is disconnected there is no risk of a spark.

 

I read something a while back on Mazda telling dealers to not let cars sit on the lot without starting them to keep the battery charged. I'm not sure what the parasitic draw is but I really don't want to discharge the battery in freezing weather, anytime for that matter. I'll put the charger on it for 8 hours or so then pull the ground cable. It should be fine until I return and I won't have to worry.
Thanks for the information.

 

It is very common on dealership lots that interior lights get left on doors are not locked ext. So, this is not anything in the real world of owning a vehicle to consider as part of any concern.

Lot boys routinely wash and charge battery every day!
Show up early enough in the morning and you can witness that I suspect at any new vehicle and even some used car dealership car lots. e

 

Last year we left our 2020 CX9 with the original battery parked in our unheated garage (Philadelphia area) during our Jan-Feb two month stay in Florida. Started right up upon our return....no issues. I have a portable hand held battery charger just in case but have not needed so far. I'm guessing a 2023 parked for five weeks should have no problems.

 

I would not make that assumption and with all the batteries we replace from Airport extended parking from customers killing their batteries I would not really go by that advise.