ws2000

Car's been in storage since the middle of October.... I realized today that I hadn't disconnected the battery. Checked and there's nothing on they - the dash lights don't come on at all. I didn't have a voltmeter with me though, so I don't know how drained it was for sure.

I have it on 2A trickle right now - any suggestions as to how long to leave it charging? Once charged back up, I should be able to not worry for the rest of the storage period, right?

The garage is kept just above freezing - 2 to 3C - do you think the battery will be ok?

HondaGal

I dunno, but 2 years ago, I did the same thing... I didn't bother charging it at this time. When spring rolled around in July I put the trickle charger on for probaby 12 hours (not sure what the time frame should be) and fired it up. It worked fine, and I have had no problems since. Last year I unhooked, left the battery in and zero problems starting. This year.. the car sat about a month.. I went to start it and the battery was dead. My alarm drains it. I charged it up, again 12 hours, took it for a spin and then put it away for the winter (unhooked battery)

Oh don't forget to locate your radio code..

matrix

Once you start the car up, the alternator will fully charge the battery when you drive it.

ws2000

I realize that the alt will charge it back up, but I thought I'd heard that storing a drained battery in the cold was bad for it? Or is that a myth kinda like batteries on concrete?

a_peep

Ya just don't turn it off until you're confident it's completely charged. (I did that when I took out my rsx from being parked about 1 month ago, both turning it off and it wasn't charged and not disconnecting it to begin with).

xviper

Charging a heavily drained battery by running the car is very hard on an alternator. It will work overtime and is not really designed to do this. I suppose once or twice will do little harm but it "could" reduce the operational life of the alternator. A 2 amp/hr trickle charger should be fine on a badly drained battery for 12 - 24 hours. You are far better to use a "smart" charger as these will bring a battery up to full and keep it that way and no more, no less. They have a quick disconnect that you can permanently install on the terminals and use the charger anytime the car sits for more than a week or two. Look to a motorcylce shop for these smart chargers.
ps. Honda motorcycle division recomends a smart charger on all their ECU equipped bikes when the bike is not used for more than two weeks. ECU's really don't like diminishing voltage. It is better to completely disconnect the battery and take it inside than it is to risk having the voltage drain too low. They can have irreversible brain farts.

VTR_Gary

When a battery is dead, the fluid changes chemically from acid (with a very low freezing point) to water. If your battery contains water and has frozen, the expansion can crack the plates and you'll need a new battery. Trickle charge it, see if it accepts a charge, cross your fingers and it might be ok. Hard to say. Depends on how dead and how cold. Hope its ok!

VTEXTC

On an unrelated note, can anyone explain how/why corrosion forms on battery terminals? I have never had this problem with newer vehicles (S2000 & Tundra), even those that get driven daily and exposed to the elements. I find this is a common inssue with older cars such as the Merkur. Does it have to do with the battery? Old cables? Or just dirt and grime under the hood which encourages corrosion?

Thoughts and comments please just for curiosity's sakes.

Cheers
Asif

koala

Asif... is it a different type of metal on the battery posts in your Merkur? Corrosion can form easily on certain types of metals... even with very small amounts of condensation.

xviper

I "think" it's a combination of the terminals and cables being exposed to the environment (ie. air and moisture) and being of older construction. Newer cables tends to be of better quality (tighter winding, thicker gauge, etc.). The moisture in the air, in conjunction with the current running through the terminals & wires, causes the formation of copper sulfate (both cupric and cuprous) and probably sulfites as well. That's the powdery deposit you see both on the terminals and also withing the strands of the exposed wire (making the ends fat and bloated). If you were to cover the terminals and what wire is exposed with Vasoline to keep the moisture from getting to it, you might find the corrosion and deposits reduced.

edit: Oops, forgot another important aspect. The older batteries tended to leak sulfuric acid fumes (where the sulfate comes from) out the caps and from around the terminals. This is not so apparent in today's sealed, "maintenance-free" batteries.