battery maintainer and storage

[brianw]

I have my 400E all polished and ready for storage and today I was installing the battery maintainer and read in the insert, "to use only in a well ventilated area". I have the car cover on with the maintainer sitting in the trunk and the lid closed...not great ventilation.

Is this just a perfunctory disclaimer, or is there another way to use this device while a car is in storage?

Thank you.

[engatwork]

The battery can give off flammable, invisible gases while being charged. I'm not sure what a battery "maintainer" is but I suspect it is just a trickle charge device.

If I were in this situation I would have try to insure that the area is ventilated while the "maintainer" is hooked up and plugged in.

The only battery I "maintain" is the lawn mower battery and I put it on trickle charge about a couple times through the winter. BTW - the battery is not in the lawnmower during this time.

[brianw]

engatwork,

I think what I am referring to is also a trickle charger. It just keeps a charge on the battery and turns itself off and on as needed to avoid overcharging.

I left the battery in the car to start it with some regularity, but maybe a better idea would be to remove the battery and re-install as I need to start it? I was thinking of starting it once a week to let it run and at the time was not enthusiastic about putting the battery back in every week. But if this is the safest route, then that is what I'll do.

Thanks for your help!

[Ken300D]

The battery can produce hydrogen gas while charging.

With a trickle charger that is also automatic, there will be a very low amount of gas produced. It will have plenty of time to dissipate before reaching an explosive capability. (I still wouldn't advise smoking when you open the water-fill covers on a maintenance battery. )

Also, a car cover is probably not tight enough to hold hydrogen, which is a very small molecule.

You might get a hydrogen gas issue under heavier charging in some enclosed space, such as if you charged the battery inside an upturned plastic garbage can.

I think your planned storage strategy will work OK.

However, if you are going to start the car once a week and run it a bit, there is actually no need to trickle charge at all. Good lead-acid batteries lose something on the order of 1/10 their charge per month (quoting from memory here...)

Ken300D

[loubapache]

The problem with modern MBs is that it drains battery sitting. My 97 E320 has that flashing red LED on the radio and the anti-theft device. Both are draining the battery. So I use the automatic trickle charge once in a while just to make sure the battery is fully charged.

I have a friend who works for Johnson Control and he said that if a battery is kept full, it can have a service life greater than 10 years. He said premature failure of batteries is because they are not kept fully charged.

I agree on a couple notes: (1) MBZs tend to "trickle" a battery to the point of not being able to crank the engine over. It's happened to me on a number of occasions; and with a fresh battery (I only drive my car once per week). Hence, my reason for purchasing a "battery tender". (2) I have been keeping my car under wraps in the garage with the battery tender in place. I think the principle is somewhat different than a trickle charger; the battery tender has some "intelligence" built into it. That said, the amount of gases produced (if any) could not possibly be harmful (IMHO). However, for safety's sake, I always wear safety glasses whenever connecting/disconnecting leads to the battery terminals.

Brian16V

[brianw]

Thank you all for your responses, and Brian16V, that's what I have...a battery tender!

Thanks!