7 battery basics to keep you charged up this winter


Winter is now upon us. Your vintage car is probably safely tucked away with its battery connected to a trickle charger, but the battery in your daily driver is now subject to stresses it doesn’t have in summer. Here are a few of my tips for winter battery survival.

This is a companion discussion topic for the original entry at https://www.hagerty.com/articles-videos/articles/2019/01/15/7-battery-basics-keep-you-charged


I’m happy when I see topics like this pop up. As a dealer technician I see alot of miss information about batteries go around. In today’s vehicles it does more then just start the car and keep your radio presets.

The days of checking the specific gravity and water level in batteries are preety much gone with current battery technology for automotive. Thankfully I haven’t had a battery explode from a hydrogen leak in about 10 years.


And sometimes it’s just a mystery. I put a new battery in my 1982 Lincoln in November 2017 and by February 2018 it had given up the ghost. Yes there were hard starts in cold weather, although I only started it 5-10 times with that battery, and all the electronics in the car probably led to some parasitic drain but it’s hard to see how those things conspired together to kill a battery in 3 months. Maybe it was just bad.

The lesson is you just never know, but you have to be prepared. I got carb work done to make the car easier to start and now I always disconnect the battery when I’m not driving it (something a lot you already know to do but I’m a noob to old car ownership). So far the new new battery has held up 11 months. Fingers crossed for the cold weeks ahead.


These articles are a bit helpful news to a “newby” at classic car ownership- like myself. Always loved old cars, yet no mechanic! I have been concerned regarding the battery and alternator/generator in my newly purchased '71 Dart Swinger… (rebuilt 225 Slant 6, I’m told). Previous owner said the battery “exploded” at some point burning paint off the inside of the hood at the site. The only time I heard of a battery exploding before was in an article I read saying a battery was “charged to fast”. (question follows) My dash alternator gauge needle STAYS “off the chart” toward “charge” side while driving (at any speed). At neutral/ idle, it looks normal (IMO)- hovering just above center mark toward the charge side. Is that seemingly radical needle indication to the far right normal for some older cars? I do not recall that in a '55 and '66 Chevy trucks I had as a kid. Does my alternator and/ or battery need to be checked and “match” in some way? I have tried search for appropriate size of both on line and can not find any answer. Any help from your readers would be appreciated. Thanks, “Newby”


Bought a '97 Miata from an older friend a few years ago. When the battery went bad I jumped the car and took it to a battery shop. The Miata uses a compact size battery mounted in the trunk. The tech advised me that the old battery was a garden tractor battery. LOL, I guess it was cheaper that the correct unit.


If jump starting a battery, be sure to hook it up properly. Not just +to+ and -to- but in the proper sequence. Batteries have been known to explode when hooked up to jump a dead battery.


My advice also for long battery life is the use of a Battery Tender. I have a 4-bank Tender and I keep the non-daily drivers on it all the time. All I do is jump in one and boom it fires right up and I’m on my way. We have a 2004 Corvette convertible we bought new. Its original battery lasted 11 years and I credit that long life to the Battery Tender.
And I also put one or two of the banks on the daily drivers every now and then just to keep them living a little longer. Hey, it can’t hurt!


When you first check the battery voltage, what is the allowable low limit? ( under 12.6v, engine off)


Continuing the discussion from 7 battery basics to keep you charged up this winter:

When checking for parasitic current drain with a milliameter, first jumper the meter leads with a clip lead.
At first the current may exceed the 10ma or 100 ma scale and damage the meter. The clip lead acts as a temporary shunt in case something else is turned on. Start with a higher ammeter setting and work your way down. Of course if you have a fancy autoranging meter this does not apply.


I have a 1950 Studebaker with a 6 volt electrical system. From the time I bought it, I always found the starting system to be a bit anemic. Was easy to blame on only being 6 volts. I made sure that everything was working well, charging ok, rebuilt the starter, installed 00 gauge cables etc. The previous owner had removed all the labels from the battery so I didn’t know how old it was but four years after I bought the car, the battery totally gave out. Found a great deal on a 6 volt battery at Farm & Fleet ($49). Once installed, I was amazed at the increase in starting power. Don’t get me wrong, all the other work was well worth it but I do wish that I had just replaced the battery in the first place.


Cold weather may put additional stress on a battery, but nothing shortens their life, like the heat. While most people seem to get 5-6 years out of a battery in Ohio, now that I’ve moved to Savannah, most people only average around 3 years (and this is in their daily drivers).


Also be very cautious if a car sat for a while in below 0 degrees. Make sure the battery is not frozen, if you try to jump it , it will explode ! A lot of people miss this !


@geok86 - You make a good point. I was blown away when I bought a car in Texas and when I took the battery to a parts house for inspection I was told “Well it’s five years old, so its lived a good long life.”


@flyntofdallas, I’m not all that familiar with your 71 Swinger or the resolution of the stock gauge. But your favorite mechanic can test the system pretty easily. Generators…which pretty much went away in the early 60’s, required an external voltage regulator to keep from over-charging and damaging the battery. With alternators, which is what your Dart has, that regulator is internal and sometimes they will go bad with no outward symptoms other than a VERY short battery life. Given the previous owner’s statements, it might behoove you to have it checked.


thank you, I’ll do that…


Nice article, a good refresher.
I was taught years ago, besides the electrical checks, look at the sides of the battery. A new battery will have straight walls. Older batteries or failing will have a bulged side. This is due to charging/discharging of the acid and lead plates. A buildup occurs.