How to Fix a BATTERY CHARGER That WON’T CHARGE
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- Опубліковано 3 жов 2024
- We’re tearing into an older Schumacher Charger. AC current enters the charger, passes through the transformer, but doesn’t make it out of the charger and to the alligator clips. Watch to find out why!
I appreciate the fact that you are openly still learning and not an expert, yet confident and wise enough to know that we all learn by doing and being curious. I just picked up a really well made charger that doesn't work... I hope my fix is just as simple. Thanks man!
I appreciate that. Good luck on yours!
Helped me fix my Schumacher Charger -- Thank You! Nice clear video!
You should look at a couple more videos of guys fixing old vintage chargers. They kind of rebuild them using the original transformer, but they explain the rectifier and diode pretty well.
I’d be interested to learn more! Where would you recommend starting?
I'd guess that the primary (input) side of the transformer has perhaps 120 wraps around it. The secondary (output) side of the transformer ultimately has 14 wraps, say... but you indicated that it's center-tapped on that side so it's really 7 + 7. If you put an oscilloscope across the outermost connections on that side of the transformer and everything were powered on you should see a nice 20V sine wave peak-to-peak but we think of this as 14VAC RMS (root-mean square) as sort of the average power. The sine wave goes above and below the zero point. Next, run that through two diodes (back on that heat sink plate) and you have a half-wave rectifier. For that original sine wave, only the positive voltages pass through and the negative voltages are filtered out. This circuit just wastes half the current as heat but it's similar to what you'd find in most microwave ovens these days, for what it's worth. As a result of that wasted energy, it generates extra heat in the heat sink and apparently was sufficient to desolder one or both of those diodes. When the switch is in the 6V mode it uses the center-tap to only use half the output of the transformer (7VAC RMS) which translates as 7V pulsing DC through a half-wave rectifier.
Ok NERD
I have a charger similar. It's 12v 2amp and 10amp.
It's only putting out 10-11v. I can't figure out why.
The wire connectors and connections on the inside do have surface rust.
Would that be enough to lower the output voltage, or do I have another problem?
The Center Tap on a transformer is the return path for 12 volts A.C. If you were to disconnect 1 of the windings on the secondary you would get the 6 Volts A.C. needed. So the 2 wires now (you must not disconnect the center tap) would provide 1/2 of the voltage. After that the remaining voltage goes to the diode to be rectified to 6 volts D.C. Thats where the selector 6 or 12 volt switch does the job to remove one half of the windings on the secondary are disconnected. Hope this Helps. Good detective work on fixing the charger!
It’s a good explanation, and I’m trying to process it and take it in. I think I need to be more familiar with how the transformers are wound to better understand your explanation. Thank you for taking the time to help me learn!
@@Duby4life I wrote a small essay but lost it because I didn't save it. However the coils are wound on a machine and the transformer Has an E type of metal frame which the coils are inserted either both outside legs or the center inside leg with one coil wrapped over the other coil in the second case. The the transformer is finally assembled with iron rectangular strips to fill in the spaces of the plates on the E form. They may be welded or bolted together. Look on the web there are hundreds of videos and tutorials. A lot of them really go way overboard with complicated Math. But some are quite good on the other hand. Heres a sample link :
ua-cam.com/video/M9ytpIMB5d8/v-deo.html
@@amiga8761I found that video very useful and simple and not at all long winded,even though it wasn't intended for me but thanks either way
I wish i knew your friend im always stumped when it comes to electronics, the reason im watching this actually is because i bought a brand new in the box car charger for ten bucks from a clearance table and im sure it can be fixed, still working on it
What brand and model is it?
@@Duby4life providence automotive 2/6 amp 6/12 volt battery charger
@@Duby4life it just turn on and the light for charged comes on no matter what battery I hook it to ,after inspection of the inside I saw nothing that would indicate an issue
www.ruralking.com/battery-charger-bc26a this one?
@@Duby4life yep that's it
Thanks for the video. It was nice to see inside without needing to take mine apart. Mine is putting out 12VDC so likely a different problem.
This looks similar to the inside of my roll-around shop chargers. I was buying a new one very 2 years or so for my 12 bay shop. My friend replaced the old diodes with better diodes that had a stud. Just drill a small hole stick the stud through and put the nut on (no soldering) That was 8 years ago and my employees weren't able to kill it.
Sounds like a great improvement! So many things are built to break these days. A simple replacement like the one you’re describing is a brilliant way to beat the “disposable system.” Nice work.
I think I may have to replace the diodes in mine... its a Schumacher SE-82-6 (older taper model) and pulled it out today zero volts across the clamps! 😢
Great idea. It is hard to solder to a heatsink because the entire purpose of a heatsink is to keep thinks cool.
This video was very helpful... i found the problem at the beginning of the video, the wire was lose 😅
That is always the best problem to find! Nice job!
With ALL due respect, in keeping the alligator clips apart, it would be wise to clip them to a NON-Conductive place rather than the edge of the table which look like steel to me. If I'm wrong, then I apologize. Have a great day and stay safe!
It is definitely good to do as you say! So to anyone who didn’t consider that, this comment is a great reminder! My table is wooden with a poly laminate on the front. 🙂
A diode is for converting AC to DC. One diode can make a half wave rectifier and two diodes can make a full wave rectifier. The voltage coming out of a transformer is AC and you need to convert it to DC to charge a battery.
a curious thing i got one of those and measure the voltage and it was 0 but when i plug it on the battery it started giving charge , i guess it has to be under load to give voltage, also it took like 14 hour to fully char my truck battery at 10 amps so dont expect a fully charge batery in 3 hours like the new smart chargers
Hey there! Not sure what kind of new smart chargers are out there right now, but if yours only gives voltage when connected to the battery, it is likely an automatic charger, not a manual like this one. They can look identical on the outside, similar in the inside even. Some of the transitional automatic chargers (when they were transitioning from most things being manual to everything being automatic) may still have a transformer in them, but with extra circuitry.
Thanks heap, my problem was the wires connecting to the clamps
That’s always the first thing I check! Glad it was helpful. Thanks for watching!
I bet I've had five battery chargers fail over the years. The only one I have that still works was a cheap one I bought at pep boys 20 years ago. I even left it out in the rain and it still works. The more I spend the less luck I have with them.
I here ya there!
I got a bunch of those from the dump and free ones at rummage sales. Transformers are great for projects.Have only had one with a bad transformer. All the rest were bad SCR's or diodes.
Those would be some nice finds! Usually I can get them going again. I have a few that are giving me some trouble atm. Have you ever repurposed any transformers for other projects?
Think of the transformer as pulsing power in and out which is “alternating current”
The diodes in this setup only let the power go out which is “direct current”
The cent tap of the transformer is the “common” which the out current comes back to after it goes through the battery..
The trick to using a modern diode replacement is figuring which direction to place it in the circuit..
I believe you. I’m still trying to wrap my mind around what you’re saying though. There’s lot here I’m not familiar with.
As far as placing the diodes in the right direction, I’ll believe I was able to use the continuity setting on the multi meter for figuring that out.
By
I've got this 1:40 amp 2 amp 200 starting amps. hasn't worked for a year and I remember an old friend of mine passed away once told me that battery charges have a fuse right here on the back left normally. So between tonight and tomorrow I'm going to find out. Of course I turn to UA-cam to search and your explanation I like. check the cable clamps connection. Okay I was looking right past that. So I'll be checkin that first before I take it apart. Indicator lights they light up showing where I've got to sit too but the actual charge like never lights up. I used it one day turnaround to use it the next day and did not work
Did you ever find the problem?
You are awesome. Thank you for sharing
Glad you found it helpful!
Witch wire is positive? Wire with lines on it ? Clamps are missing
Usually the positive has three rubber lines formed into the insulation while the negative is smooth. I would always double check with a multimeter.
Great job
You have to hold the tip of the soldering iron on the two pieces to be soldered together letting those pieces melt the solder (flowing it). Never try to melt solder directly with iron and try to stick cold parts together. You can get away with it every once in a while but it’s gonna fail
I follow. Hot or not, nothing would stick to the surface where it had been damaged for some reason. Hence attaching to the new spot.
Think of AC (or "alternating current") as like a sine wave. it alternates between a positive phase and a negative phase: 0V to +60V to 0V to minus 60V back to 0V kinda like this: _ -- _ -- _ -- _ -- _ or ~~~ The Diodes "flip" the negative phase of the cycle to a positive one so then the current only goes positive: 0 to +60 to 0 to +60 to 0; like: -------- or ^^^^^. (hard to draw with keyboard characters )
"Direct Current" should go up to +60V and stay there, but when simply "flipping the negative AC phase to positive" you get bumps or "ripple" (which might look more like ^^^ on an oscilloscope) and usually a capacitor is used to smoothe that out which is what the "AC to 12V DC converter" that you'd use to test a CB or car stereo with has.
Charging a car battery is not as sensitive to ripple as a stereo or a CB is and thats why the insides of car battery chargers are more simple than the insides of your 12V DC converter / power supply. The battery itself is like a giant filter capacitor, which is why you -can- test a car stereo or CB with a battery charger, so long as you have a battery between the charger and the device.
HELP! I have a Schumacher 250 Power Booster 10/30 Fast Charger. Someone broke the switch off. I opened it to get the parts to replace, but the auto store doesn't have it. What can I do?
Send me photos of the issue to duby4life@gmail.com and I’ll see if I can walk you through a fix.
My charger the fan keeps blowing, stuck on, last time I unplugged it waited a little bit and plugged it in again and the fan shut off , but it is doing it again, is it a easy fix or?
I’m not sure how difficult or simple that would be. If the fan isn’t hindering anything, it wouldn’t bother me to have it on all the time. I’d simply unplug it when it wasn’t in use.
Sometimes it’s something tiny and failed in the printed circuit board. That’s where my knowledge gets fuzzy.
DIODE is a ONE WAY DIRECTION flow to Prevent Problems
Yes, I am curious what type of problems would arise if current flowed back to the transformer.
@@Duby4life this is kind of funny…… you know like problem problems. Like bad problems. Not like financial, marriage or world problems but you know electrical kind of problems. Hope this helps 😂
But on a serious note at a guess I’d think maybe because of having battery on one end power from there could flow backwards into the transformer or even another sensitive part that might sit there. Like if you pull the plug and tested the prongs would the 12 volts from the hooked up battery flow backwards to the outlet. If you plug back in you could have your 240v(Australian) plus the 12 volts sitting in the power source leads and might cause a surge.
Maybe transformers need to be empty when power is inputted or they blow up. I swear I’ve heard “ the transformer blew up” listening to savvy electrical mates throughout my life 😂.
The other thing and I only remember this because one day I picked up an old circuit board holding onto that square box transformy thingy and my mate nearly fainted from disbelief and went mad at me haha. Yep I’m traumatized. So my only logical interpretation is that electricity from it may have killed me.
“ you f@&ken idiot, what are you doing, don’t grab that” didn’t have much more education than his abuse haha. It didn’t feel sharp so it couldn’t cut me and I wasn’t carrying it above my head so couldn’t fall therefore killing me. So from this experience I have concluded electricity may actually be stored I’m them. If you pull a power tool battery charger or laptop charger the light tends to stay on for a while after doesn’t it? Come to think of it I’ve always wondered why Stick welders don’t have a trigger or a foot pedal. Wouldn’t that make it far safer than having a live exposed end Constantly. I don’t know how many times I have gone to put the hand piece down onto the metal bench the negative is clamped to. Haha. Also from what I have seen 12v battery chargers don’t have a switch to turn them on/off. Does this mean it always has to dump the left over charge because of what the original poster explained so thoroughly about causing “problems” 😂🤷♂️
Any electricians/gurus out there that can chime in?
@@brickmate4802 Haha, I appreciate the laugh. Maybe your friend just didn’t want you touching his project. 😂
I know modern 12V chargers are not always pushing out 12-15V. They’ve done away with the large transformer-style chargers, at least in the US.
I would think that it could drain the battery if they weren't there to stop 🛑. The backflow. I know my dad's very old charger and it probably belonged to his father before him, my dad always said if it isn't plugged into the wall and turned on. Then unhook it from the battery 🔋. That thing has to be 60 years old so it probably doesn't have all the preventive measures for 🦺
I eat one diode every day, just to stay moving forward
5:15 - if you had prepped the "old spot" surface, the soldering would have gone fine.
Soldering 101:
Clean surfaces
Sufficient heat
Good flux
Proper solder for the job
The solder follows the heat
It is really that simple, dude.
Iben doing this stuff since fourth grade.
It ain't rocket science.
I'm just sayin'...
...
PC: it’s very possible I didn’t get it as clean as it needed to be. I did wire wheel it and sand it to the point that I was eating into the aluminum though. Still the solder only beaded up on the original point of solder when I went to reattach.
I appreciate to feedback though. 👍🏻
A rectifier
I need 12 volts and 10 amps power transformer
Mine had a little spark and stopped working
Uhoh! Could be a lot of different things… where did the spark come from?
What solder did you use
I believe this was my usual solder. 38% Pb maybe?
My charger nothing comes on and I didnt touch the ends together this happened after I stripped the wires back after no lights no nothing it's like it into sleep mode and won't wake up
Hi Rand, is it a manual charger like this one?
When you plug it in, can you hear the transformer vibrating (indicating the AC power is reaching the charger)?
Try checking for voltage inside your charger. Trace your positive and negative leads back into the charger and see if the DC current is flowing out of the transformer and to/into/through those leads.
I need to replace my power transformer does anybody know where I might be able to buy one for a Shoemaker battery car charger
I’d try to find an identical model on eBay, perhaps even a non-working one. Use it for parts. Often times, the wires coming out of the transformer are very specific and unique, at least they seem to be. I’ve taken apart many 10A chargers and seen many differing transformers.
Wow. Good initiative, but use a torch and bang you done son
SO, NOW THAT IT'S WORKING WANNA SELL IT?
Are you really interested? I have others like it.
I can take today off if i need too?
What?
Not enough volume cant hear you !
Thank you for the feedback! The quality of my videos is something I am constantly seeking to improve.
🎉
Should I drink in the video of the butt thumbs down