Can you buy a decent Battery Charger anymore????

[tigman250]

Tonight I went to back the Jeep out of the shop, battery is low enough I just get the clicking starter. Put my large and expensive roll cart charger on it and put it on 200A boost and only get a second or so of it helping then the “smart technology” shuts down the output. I then put it on 10A charge for about 5 minutes to build it up a bit then went back to boost and again only got a second or so boost before it shut down again. Frustrated and in a hurry I went and grabbed my 30+ year old $20 charger that is the size of a toaster, hooked it up, put it on the 50A boost setting and the Jeep struggled but sprang to life after a few revolutions.

WTF, I paid around $250 for this piece of crap and constantly find myself highly disappointed in it and just grab the $20 one I bought from Quality Farm and Fleet when I was just a lad. Does anyone still make a battery charger that will recognize a battery under 10 volts and will boost longer that .005 seconds? I really need to go over my enemy list to find the person I hate the most so I can gift them this charger

[Whitetrash]

Hopefully Gerry will weigh in on this. He understands the cicuitry enough to Neuter the bastards. I haven't had to tackle it I still have an Old school charger.

[digr]

It can be bypassed but I can't tell you how without looking at it

[Shade Tree Welder]

I have the older version of this, has held up well.


https://www.amazon.com/Schumacher-SC...%2C1444&sr=8-5

[mccutter]

I've had this one for a few years now. Does what I need it to do. 6/12v 3/15A. $65 at Lowe's, same price I paid back then. LINK

[tigman250]

Originally Posted by digr

It can be bypassed but I can't tell you how without looking at it

What do you need pictures of? I may as well hack it apart, it’s absolutely useless as is!

[flametamer]

The only 2 names you need to know when it comes to battery chargers:

https://associatedequip.com
https://www.schumacherelectric.com/

Dt

[Ironman]

Originally Posted by Whitetrash

Hopefully Gerry will weigh in on this. He understands the cicuitry enough to Neuter the bastards. I haven't had to tackle it I still have an Old school charger.

Every super duper battery charger today has these basic components.
1. transformer
2. rectifier diodes
3. meter or stupid flashing lights
4. switch for hi/lo charge
5. printed circuit control board.

All you really need is shown in this diagram
5. First of all, chop out the printed curcuit.
4.Then spend a few minutes to understand the hi/lo switch. This switch changes the taps on the primary transformer windings to give you 6/12 volts and high or low charge. Most people don't use 6 volt charge windings at all, so they can be ignored.
3. A linear ammeter is a useful thing and you may want to install one if it has none.
2. Rectifier diodes are important. A minimum of 2 is needed. four is better in a full wave configuration
Often the printed circuit board and rectifier diodes are mounted on a piece of aluminum to act as a heat sink. People like to slap the charger leads together to see if there is a spark. This can and does blow these diodes (and really fries a selenium rectifier with all the fins) as they are only rated for a bit less than the charger output. When I oldschool a charger, I replace them with up to 400 amp diodes half the size of a turnip that I get from surplus sellers. I use a aluminum cylinder head off a flathead Briggs &Scrapiron as a finned heat sink.

That's about it folks.
The first time you do this you may have trouble recognizing the components in the box, after that it gets really easy.
The wokeys will say "o god, you will blow up the battery" No. As the battery charges, at lets say 10 amps, the meter will show 10 amps, and as the battery fills up, it will drop to 8,6,4, and settle in at 1.5 to 2 amps when fully charged, when the charger is set for 10.
This is a trickle charge.

I hope this is understandable, tigman

[digger doug]

A 12 vac xformer won't get you where you need to be....

[digr]

I traced the 12 volt output wires back, found the 12 volt output on the transformer after the diode bank and bypassed the voltage censor. New chargers won't work unless they cense voltage. Do this at your own risk