Technical UPDATE - How long can you safely charge a battery?

A while back Brenda & I got T boned at a intersection and fortunately Brenda didn't het hurt and I had hurt my wrist, everything is cool now but the shop van was totaled and at that time it had a fairly new battery, I removed it and stuck it under the workbench at the shop.

The battery was getting old in our replacement shop van and wouldn't crank Thursday morning so I did a quick charge (45) minutes and put the old battery in Brenda's Ranch wagon,fired it up and drove the car less than 5 miles, that was last Friday, today I got in the wagon and the battery was deader than a hammer.

This is a sealed battery, how long can I safely leave it hooked up to get a full charge? HRP

 

My charger has a light on it that blinks when fully charged. I usually leave it on for about 24 hours while charging at a 2 Amp rate. Takes about 6 hours at a 10 Amp rate. I've always wondered how long is too long. I guess it depends on the sophistication of your charger. I've also read about batteries tha have exploded. My charger is by no means top of the line.

 

How many amps does your charger put out? Also a picture of it may help. Gary

 

You need a smart charger that reduces the charge as the battery charge goes up. Then when fully charged it goes to a float where it just keeps it up to snuff with a very minimal charge.

 

Sounds like you have a bad battery. 45 minute charge on a good battery and a five mile drive should have the battery in fairly good shape. Assuming you had a 8 to 10 amp charger. Batteries don’t like to set around unused, especially in a discharged state.
Chargers are kinda funny. They will charge a low battery real quick for the first say 1/2 charge. But then they usually start reducing the rate of charge for the second 1/2 and it will take a lot more time to get the second 1/2 100% charged. But a 3/4 charged “ good “ battery will still function .
But the best way to charge a battery is long and slow.
Sometimes a long slow charge will bring a battery “ back” , sometimes not.



Bones

 

HRP- if your battery is rated for, say 600 cca, you'll need a long time charge to get that back. I have an electronic Napa charger and that thing will charge for several days getting one of my batteries back up if I leave a key on after troubleshooting, etc...

 

Here is a chart that will help. Good luck!

 

My old friend at the gas station had a battery that was a few years old in his car, and had sat over the winter. He threw it on the charger and about 40 minutes later I heard a loud BOOM, it had exploded and blew acid all over the work bench, thankfully no one was near by when it happened. Never have trusted old batteries since, going dead because of light or key on is one thing, but when they set too long and dont hold a good charge, nothing is going to bring it back.

 

Friends and I swear by battery tenders. They will top off a battery and "condition" it (float charge)
They won't bring back a battery below a certain voltage,(I think 11) but I bought an old Western auto boil dry 3 amp charger at a garage sale,brought mine up after a few hours and put it on the Tender.Done this with several batteries.
I bought a new Schumacher "smart charger" and it won't kick in unless it's 11.5 I think. I use the dumb charger to bring it up enough.

Anyway get a tender, they are good keeping small batteries healthy like lawn tractor,motorcycle etc

 

Listen to upspirate, sometimes “smart” chargers are kinda dumb!






Bones

 

I had an old Century 2/10 amp with a 55 amp jump setting that was awesome since the mid '70's, but quit working so I replaced it with the new Shumacher that had programs depending what type battery you are charging.
I've heard others say to hook up a good battery in parallel to fool it into starting a charge, then disconnect the good battery from the bad and it'll work. I haven't hd the new ones boil a battery dry though.

But the battery tenders are they way to go, keep them hooked up to batteries you don't use often and will save one if they can be saved

 

Smart chargers were made for dump people.
A regular charger needs a competent operator or it’s going to blow shit up.

 

I know a guy named Charlie in Sodus New York who charged a battery for 14 years, Said it was still good.

 

I have been around wrecked vehicles most of my life, and it’s not uncommon for a battery to be ruined by an impact. That may not be the case here, but it is a possibility.


Sent from my iPhone using The H.A.M.B. mobile app

 

My HF charger is one of those so called smart chargers, it won't even turn on unless there is a little voltage in the battery. It charges like heck for a while, then it cycles until it gets to full charge. I can leave a battery on it several days and it will cycle and never overcharge one.

My old Schumacher that I had kept over 25 years finally bit the dust is the only reason I bought the HF one. It would boil a battery dry if you didn't take it off after about 12 hours.
I miss it, I also used it a lot to do electrolysis cleaning every once in a while, the HF I can't do that. But I couldn't find another like it around here, all were the smart kind, and HF was the cheapest.

 

Some of the newer AGM and sealed batteries will not take a charge from a regular charger. They need a special charger that also puts a draw on the battery while it’s charging. But it should take a charge in your vehicle.

 

Charge the battery long enough so you can start the car. Then go for a couple hours drive. It should be good to go. If not, then buy a new one.

 

Buy an old style at a yard or estate sale

 

True, but I'm old and sometimes forget, or have other things to do

 

This is the type I have, Sears Heavy Duty charger/starter.
I've had it for many years. HRP

 

I seldom go to yard sales and never estate sales. Yard sales around here are mostly womens and kids clothes, and the few estate sales I've been to they wanted new prices for junk. Everybody thinks their junk is gold. I do better at pawn shops and thrift stores.....

 

A few years ago, I imported an OT damaged vehicle from Japan to New Zealand..
The battery was located in the rear and was the size of an Explorer battery (quite large)..
The day I picked the car up, I had to jump-start the engine, I drove the car (fitted with an alternator) 200 miles back home, and the next day the battery was still dead..
I put it on my home charger for a couple of days, still no result..
After a couple of days I took it to work, and put it on a commercial charger for 3-4 days and it charged right up..
That battery lasted for another 6 years with no problems..

 

With three cars and not able to drive them all at once I use a tender to keep the batteries ready to go.
The roadster battery has been in there now for well over 7 years.

 

I've heard that it's hard on the alternator to drive a car with a low battery.

 

My car`s alternator has been in it for over 50,000 miles. It keeps 3 batteries charged.

 

It sure doesn't do them any good, they aren't really designed for it. On cold subzero winter days after a jump start can hear the belt groan as the alternator loads up. As somebody mentioned after a hard collision the battery could be damaged internally. It's "probably" fine, right, but batteries are nothing to fool around with. Internal sparks can cause a battery to explode.

 

Danny , your battery was probably damaged in the crash. That's why I never run a wet battery in a round track car or a drag car. The plates suffer damage every time an impact happens.
I have cut the tops off batteries and inspected them . A drag car is like a car wreck every time you drop the hammer unless you mount battery with the plates aligned with the car.
The accident probably knocked the plates loose . You can try charging your battery through a known good battery and sometimes you can revive a dead battery. Just be careful , my dad was injured by an exploding battery. Got some nasty acid burns.

 

Packing on a surface charge will get the car started. But surface charge is just that, on the surface and sheds quickly.

Charging batteries is like sex,,,
A quickie gets it on its way but a good long steady round is way better.

An old timer said charging batteries and surface charge is like back filling a hole,, you can dump a bunch of stone in quickly to get it over with. but it’s going to settle and need more then that settles and more and settles on and on you keep fucking with it.
It’s Way better to go slow by adding some and tamp it in then some add some more and tamp and more and tamp.

 

I use a battery tender on the convertible. As the battery becomes charged the rate goes down and when fully charged shuts off .

 

A good "load tester" will let you know if your charged battery is any good.