Old school 10A battery charger, needs transformer

[Cujet]

I have a smoking transformer in my favorite battery charger. You know the kind of old, unregulated 6V-12V charger where it produces about 8-15V open circuit at the leads, and the leads spark nicely when touched. It will push a charge any 12V battery, of any size, even if the battery is so dead it reads 0.000V.

I tried to purchase a replacement charger from HF that "seemed" to be nanny free, but it too has the electronic nannies that prevent it from working for my needs.

I want to purchase a replacement transformer. Any thoughts on where to get one?

Yes, I clearly understand that dead batteries are useless. But I use this to open my driveway gate when the batteries fail and other emergency uses, such as when the wife leaves the headlights on for a week. That kind of thing. The other one won't do the job.

 

[2010Civic]

There are new chargers that will charge a battery at 0V. You do have to push a button to get it to work.

I would look for numbers on the transformer and start googling.

 

[Eddie]

Look on Creg's list for a replacement? My dad had one with a big vacuum tube and it also gave out 12+ unregulated volts.

 

[fsdork]

These guys have a few:

https://www.digikey.com/en/products/filter/power-transformers/164

I've had really good experiences ordering from them. I'm in Canada, but the reviews also seem very positive in the US.

 

[chemman]

Check Goodwill stores, Salvation Army stores, or garage sales. Another thought would be to go to a ham radio "hamfest" and go through their flea market area.

 

[Cujet]

These guys have a few:

https://www.digikey.com/en/products/filter/power-transformers/164

I've had really good experiences ordering from them. I'm in Canada, but the reviews also seem very positive in the US.

Thanks, I did look there, but it seems the type that makes 8V and 15V open circuit can't be found anywhere.

 

[brianl703]

If I need a battery charger to charge a completely dead battery, I use a variable power supply:

https://www.amazon.com/4-Digital-Precision-Adjustable-Switching-Multifunctional/dp/B07ML2MP9Q/

I can put 16V into a dead battery to try to get it to charge with one of these. I can also limit the current for charging smaller batteries.

 

[Cujet]

If I need a battery charger to charge a completely dead battery, I use a variable power supply:

https://www.amazon.com/4-Digital-Precision-Adjustable-Switching-Multifunctional/dp/B07ML2MP9Q/

I can put 16V into a dead battery to try to get it to charge with one of these. I can also limit the current for charging smaller batteries.

I have 3 power supplies. Unfortunately, they are all 5A max.

 

[Snagglefoot]

Here is my old school unit which has a 15 amp setting plus a 100 amp “ engine start” setting. I still usually use a smart charger but it’s nice to have this bad boy around. The only “automatic” feature is that it will turn off when the battery is fully charged.

 

[AZjeff]

Might try McMaster-Carr, the link will take you to transformers.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[SubLGT]

https://www.mouser.com/c/power/transformers/?gclid=EAIaIQobChMIgITD25ys_QIV0oZbCh1_SgduEAAYASAAEgLG1PD_BwE

 

[John105]

sounds like it's as hard to find as a left-handed monkey wrench. Harbor Freight had it on sale but when I went to the store they told me everyone else wanted one and they only had 6 to begin with

 

[DriveHard]

If I need a battery charger to charge a completely dead battery, I use a variable power supply:

https://www.amazon.com/4-Digital-Precision-Adjustable-Switching-Multifunctional/dp/B07ML2MP9Q/

I can put 16V into a dead battery to try to get it to charge with one of these. I can also limit the current for charging smaller batteries.

Better yet would be a current limited 14.4V power supply. I have one for similar purposes, limited to 5 amps. Works great for almost 20 years now.

 

[John105]

I got this for $125 during the pandemic. I tested it and drew as high as 35A when connected to my car with headlights, defrost, and blower on. It really did clamp down on the voltage, stays at 13.2v or so. It was 13.6v when the draw was low. I think of it as being similar to a device in a car dealership when they let you sit in the car with all accessories and ignition working, so that battery doesn't drain.

WFCO Technologies - Innovating the Future of RV Power

WFCO Technologies is committed to simplifying, enhancing, and optimizing every RV owner’s experience through advanced power technology and proven support.

wfcoelectronics.com

 

[y_p_w]

I still have my Schumacher 1A manual wall wart. It has brought back batteries that my automatic chargers refused to charge - or at least get a battery up to at least 9V where the automatics would start working. I checked it with my automatic (has a crude voltmeter when it's not charging) and it was reading around a 16V open circuit voltage.

 

[brianl703]

Better yet would be a current limited 14.4V power supply. I have one for similar purposes, limited to 5 amps. Works great for almost 20 years now.

Well, on the one I linked, you can set it to be a current limited 14.4V power supply.