Loooong winter in storage - battery died

My Maserati will start up after about 24 hours of trickle :0

 

Hmm, I wrote about this a few times before on the forum. How well your battery tender recharges your battery will depend on how deeply discharged your battery is, as well as which battery tender you are using.

AFAIK, none of the standard Ferrari battery tenders are designed to efficiently recharge a fully discharged 100 Ah battery (common for factory-supplied chargers). They are only meant to top up the batteries, after a day's drive. At best, they will take days to recharge a dead battery that has not been damaged.

Here's the charger that came with my Cali30. It's actually not the right one for my car because my car has different battery requirements from the standard Cali30 due to its additional HELE feature.

Image Unavailable, Please Login

On the back it says it's actually a CTEK US 3300, essentially an MXS3300

Image Unavailable, Please Login

If you refer to this older CTEK charger-to-battery matching table, you will see the MXS3600 will take 25 hours to recharge a discharged 100 Ah battery. An MXS3300 will have a max 3.3 Amp capacity, MXS3600 will have 3.6 Amp capacity and so on.

I believe some of the earlier cars came with something similar to the XS800 - essentially incapable of recharging a 100 Ah battery.

If your battery was fully discharged (less than 11.75V) it can take a couple of days to recharge, assuming your charger is at least a CTEK US 3300. Even the MXS3600 is only rated to recharge a 75 Ah battery.
Image Unavailable, Please Login

 

My car lives on a trickle charger in a enclosed garage. I only take it off of the charger when i use the car. If not being used i plug in the car. No harm after 2 maseratis and years of use.

 

mjc_123, it should be fine to leave the battery tender attached 24/7 to your car. That's how they are designed to work. They protect your battery when you store your car. If you don't use it the car's electronics will kill the battery because they do not all turn off when you turn off the engine.

Any mention of well-ventilated area requirements is probably due to some technical writer regurgitating the well-worn generic concerns that a bit of hydrogen gas is sometimes released from charging lead acid batteries, even in the sealed units. Batteries are sometimes located in the trunk (BMW) where confined space may be of concern but your battery is in the engine compartment and a garage is not confined enough to be of concern.

BTW, the HELE function in my car simply means it will discharge its battery a lot more than a non-HELE car would. So my car uses a different type of battery and it can be significantly more discharged than the battery in a non-HELE car would be when it is put away. My car uses a faster battery charger to ensure its battery is topped up before the next drive.