My Battery Tender??????

Old Redneck

Old Redneck

Well-known member
My Battery Tender is hook up yo my 56 T-Bird. The Red light is on and the green light is flashing. Is it not sure yet of full charge or just can't make up it mind. The Battery is only 6 months old and was sitting in the garage not started for a month. When I tried to start it ,dead. I know I need to have it tested to see what going on or something draining it.
 
It takes a fair amount of time, I didn't know tenders would charge completely dead batteries. Just have one of those small ones that is like a wall wart on wife's PT Cruiser we hadn't driven for awhile and it required 2 days before solid green.
 
I disconnect a battery cable when the old car is parked so nothing accidentally drains it or shorts out when I'm not there.

However... :mad: I left the tender on the battery too long without checking the water level inside.
It boiled the water out and I had to buy another battery. It was 7 yrs old already but that wasn't much of a consolation.

Connecting the tender once or twice a month for a day or two would have been the better thing to do.
 
dmsfrr said:
I disconnect a battery cable when the old car is parked so nothing accidentally drains it or shorts out when I'm not there.

However... :mad: I left the tender on the battery too long without checking the water level inside.
It boiled the water out and I had to buy another battery. It was 7 yrs old already but that wasn't much of a consolation.

Connecting the tender once or twice a month for a day or two would have been the better thing to do.
Click to expand...

I did the same thing but at 7 years it owed you nothing !
 
McMimmcs said:
I did the same thing but at 7 years it owed you nothing !
Click to expand...
Yes you're right. I should be glad it lasted 2 years longer than the one in the car when I got it. It apparently had some internal corrosion and a spark when hitting the starter set off the hydrogen gas vapors inside. Kaboom !!!
This photo was after I cleaned everything up. The battery case was split open on 3 sides.
 

Attachments

  • battery c.jpg
    battery c.jpg
    71.6 KB · Views: 41
Last edited:
In my opinion battery tenders are an accident waiting to happen. I know of now four batteries that look like dmsfrr's. Two friends just this year blew the top off like the photo above. One was still smoking when my friend found it. Put a disconnect switch on your vehicle or use a battery charger (properly) and forget those things!!
 
I've used these for several years. They're very low power and I've never had a failure with one. They will not charge a low battery, and if it's down just a little it can take 2 days to get a green light.

I've got one on a small generator that's not used or looked in on very often. On it I use a cheap appliance timer. It runs 1 hour a day. I needed that Gen set for the first time in 2 years last month. Fired right off.

I had a battery that came apart like the one dmsfrr shows. It was in my OT truck and disconnected in the garage in Tucson when it happened. Fortunately no other damage.

https://www.batterytender.com/Battery-Tender-Junior-12V-0-75A

They're cheaper on Amazon
 
I suspect there are a lot of battery tenders out there that are not safe to leave plugged in. I once bought a cheapie from HF that just kept charging, and it only cost $10. I threw it away.

I have used only Deltran battery tender/maintainers for the last 7 years or so, without any problem, and I leave them on constantly. Sometimes I walk by and see the green light is off, sometimes all green, and sometimes flashing green. To me this is proof they do shut off.

I have gone as long as 8 or nine months without driving the cars, but never had any problem with any Deltran. One battery died on me, but it was 7 years old.

I have two double chargers, and three singles. Even had one on a travel trailer until I sold it. Mine do charge a low battery. They then maintain it at a low rate, that is used when needed to keep it charged.
 
If a battery is sulfating badly, including over-charging, it emits vapors (sulfuric acid) that can be ignited either by spark or lit cigarette.

If the car is put to bed over an extended period, it might be best to either remove the BAT or disconnect it electrically (maybe pop hood to allow escape of sulfation gases/fuel vapors) from the vehicle. It needs to be fully charged and then put on a QUALITY tender for the storage period in a cool area.

CLICK HERE - https://www.crownbattery.com/news/sulfation-and-battery-maintenance
 
Old Redneck said:
It finally turn green. So I did disconnect the Battery. Will watch it to see if it goes dead by itself.
Click to expand...

You want to maintain the BAT. If a quality tender, it needs to remain in service. Just remove the BAT terminals to the vehicle.

A tender is not designed/meant for charging a BATT, only maintaining a fully charged healthy battery.

Did you read the TECH ARTICLE?
 
I'm with 50fordcoupeman. I have a disconnect switch. I also like to top off my batteries a little hear and there witha traditional battery charger a couple times a year.

connecting the tender once or twice a month for a day or two would have been the better thing to do if you really feel strongly about a tender. The newer Corvettes used to come with a unit, but they were smarter style units, that sensed when the battery got down to 80% before they'd kick on an charge again. You can sulfate a battery before ya realize it. A sulfated battery eats away at the reserve, until it finally will not start the car, even though a tester shows 12 or 13 volts.
 
I use a Deltran Battery Tender to maintain the charge in my Harley battery. I remove the battery, hook the charger up and walk away from it from November to April. I have never had any problems with it. I bought the Deltran in 2006.
 
You must log in or register to reply here.
Back
Top