Battery charger

[egbinor]

I had this charger for around 40 years and it finally gave up. Diodes & rectifiers are beyond my grade.. I don't know anyone around here that works on these so looking at buying a new one. Used mostly on 6 volt tractor s and hvy duty stuff. I've heard bad stories about the late chargers with circuit boards, printed circuits etc so i'm leaning toward the old fashion type like the one that worked 40 years. I've had it so long I can't even remember where it came from?? 81 years old so that could be part of my problem... Any thoughts or ideas appreciated.. Thanks

 

[Mike(NEOhio)]

I have an older Schauer. 6 or 12 volt but it's a deep cycle battery charger and has a timer. Don't know if my FIL knew that when he bought it but I like the fact that it won't charge all night if I forget it.

 

[wore out]

It appears to have diodes (rather than an older-fashioned selenium plate rectifier), if the transformer is good it would be an easy fix, and the diodes are NOT expensive.

Would be great if you could find an electronics enthusiast nearby to give it a second life, WAY tougher than anything "consumer-grade" sold nowadays.

 

[Geo-TH,In]

If you lived close I could fix it for you.
Indiana Wilson, former co worker, drops his off all the time.

 

[amtrac]

Check out this site. Made in USA too.
Century Tool

 

[Stephen Newell]

Don't throw out the old one. I bet you eventually try to fix it after using a new one for a while.

 

[egbinor]

Is there a simple way to check the transformer?

 

[Ted in NE-OH]

The difference between selenium rectifiers and today's diodes is that selenium rectifiers have a higher internal voltage drop. So if just replacing with a solid-state diode you will have a higher output that may be detrimental to the load. Just something to be considered.

 

[miangus]

I have installed new diodes in my solar brand charger that worked for awhile but then I over loaded it and blew them. I got an updated rectifier bridge and holder on line installed easily and worked great. If you replace any wires in and around the rectifier use high temp appliance wire and connectors. They can be acquired at an appliance parts store. They are used in electric stove burners. Remember ac setting before rectifier on transformer wires dc setting after rectifier. If the transformer doesn?t trip the breaker probably ok. Should show different voltage at each lead.

 

[Russ from MN]

I have a Century 15-2-100 6 & 12 volt, been a good charger, used it yesterday!

 

[MarkB_MI]

As Wore Out said, your charge appears to have silicon stud mount diodes, which are readily available and easily replaced. Assuming they're what failed, it's just a matter of finding an appropriate substitute and replacing them.

You can confirm the diodes have failed by unsoldering their leads and checking them with an ohmeter. If they are open in both directions or shorted in both direction they're bad. A good diode will only conduct in one direction. Most digital multimeters have a particular range marked with a diode symbol that you need to use in order to properly bias the diode.

To find a replacement, assuming you can't read the part number on the diode, you'll need to determine the package type, then find a diode with appropriate reverse voltage and maximum current ratings. Note that the voltage rating should be more than double the nominal output voltage (because it has to handle the peak voltage of the transformer's sine wave output, which might be 50 volts or more), but the maximum current rating of the diode can actually be smaller than the charger's rated output because each diode is conducting less than half the time.

Here's something that might work. The <a href="https://www.jameco.com/z/SD51-Motorola-Diode-45V-60A-Rectifier-Stud-Mount-DO-5_2287503.html">Motorola SD51</a> is a 45 volt, 60 amp diode in a DO-5 case. (DO-5 has a 1/4" stud.) Ten bucks apiece from Jameco Electronics.

 

[MarkB_MI]

>Is there a simple way to check the transformer?

Well, you can check the AC output of the transformer with a multimeter. With no load it's probably between 20 and 50 volts RMS, depending on the range. But check the diodes first, since they're the most likely part to fail.

The diodes typically get blown using the charger to jump start. If you do that, you need to let the charger cool down several minutes between jumps to avoid burning up the diodes.

 

[OldFarmTractor]

I have never bought a new charger. Check out auctions near your location. Auctionzip.com might work for you.

 

[amtrac]

I had a nice "smart" charger, paid good money for it too. I have several toys that are 6V systems. Every time I tried to charge one with that "smart" charger, it would say "analyzing battery" for 10 minutes or more, then go to "charging 12V". I took great delight in smashing that thing to pieces on the concrete floor. Got to see what was inside before it went in the trash. Looked online for a "dumb" charger made in USA and found Century Tool. Love mine. Works great--I set it to what I want and it doesn't argue with me one bit.