E-mag charger busted?

[T-Bird]

My emag cant power on. The volt meter reads my "fully charged" battery as ~14V. If im not mistaken, the system needs at least 18V to run. My charger also only outputs 14V, so its no surprise to me that power in my battery is so low.

Is there something i can do to repair/adjust my charger on my end before i go out to buy a new one.

Thanks.

[maniacmechanic]

http://www.automags.org/forums/showthread.php?t=246779

[athomas]

Sounds like the 13.8 volts from your AGD cigarette lighter adapter output is passing through your charger to the battery. That would mean your charger is fried. The output of the charger should be somewhere in the vicinity of about 20 volts when not connected to a battery. If you know about electronics and soldering, you could probably do a repair yourself.

[T-Bird]

Sorry about the double post. When i posted that other thread, the board locked up or something. I assumed that it didnt go through.

I did try charging overnight. Still same thing, 14V. I checked AGD to see if they sell it...$60!!?? For a rebuild kit, not even a new one??!

Anyone got any better offers on a used one? If you are in Houston, that would be great, since id like to get the gun charged up and ready to go by sunday.

[Ando]

ROFL...I just posted in your other thread right when you deleted it :p

What I said:



Opps. My bad, didn't read all the way through your post. I just read the low voltage battery and said what i said. I've had a battery go bad on me before and after opening it up and cking each cell, I found 4 holding very weak charges. I went ahead and replaced them, reshrinked the battery and it's good as new.

You can fix your charger tho. It has a few capacitors, resisters and a regulator inside. Any one of them could have gone bad. If your capacitors and resisters look good (not blown), I would look at replacing the regulator inside. If you want I can take a look at it for you. Just pay for the shipping back and forth and what ever parts it's going to need. Parts aren't going to be expensive. You'll be looking at no more then $5-10. Resisters and capacitors that size are only a few bucks, same with the regulator.

Always ck the easy stuff first. Try a different power source before you go buying or sending it off to get repaired. You never no. :rolleyes:

[T-Bird]

Thanks for the heads up Ando.

I got the charger with one of those radio shack converters that allow me to plug the cigarette lighter end into a house wall outlet. The AGD charger output reads at 14V output. I then tried bypassing that and pluging the charger directly into my car cigarette lighter, still the same output. So im guessing that the radio shack converter isnt the problem.

BTW Ando, do you live in houston? If i could meet you, drop it off, and get it repaired by this saturday, i can pay you double.

EDIT: Nevermind, you're from Maryland. =(

Any other takers?

[Ando]

Are you good with a soldering iron?

I can't remember but I think there are 2 capacitors in the charger. If they look like the 2 on the outside of this pic...
http://www.thegeniuspub.com/Portals/0/images/article_images/2007/leaky_capacitors_common/leakycap.jpg
...they are bad. The one to the left has a bulge and the one to the right is burned. I've never seen them burn like that just bulge out. Your capacitors should look like the one in the middle with a flat top.

Your resisters will look like this if they're blown
http://www.qsl.net/i0jx/psu10.jpg

If both look good, I would suspect your voltage regulator. The one in the charger looks like this
http://www.electronicrepairguide.com/7808%20voltage%20regulator.jpg

All you need to do is open the charger (just 2 screws) inspect everything. Look for anything black or anything i described in the pictures i posted. If you find something, it'll have a part number on it. Go to radio shack find what your looking for and take it to someone that can replace it for you if you can't do it yourself. Like I said parts shouldn't cost you more then $5-10.

[T-Bird]

A friend and i tried to teach ourselves how to solder.

I remember trying to melt the solder and he and i accidentally took a big whiff of a big puff of smoke that came up. We were both light headed for the rest of the day. Not sure if we got poisoned by lead smoke or what. Ever since then, ive just trusted that work onto the pros...hahaha.

I think i know someone i can pass the post onto and maybe he can fix it for me.

Thanks again.

[Ando]

Sound good bro.

[athomas]

When the charger is on and connected to the battery, is the red light on? Does it switch to green right away or does it stay red and then switch to green after a bit of time? Red indicates the fast charge part of the cycle. Green is the trickle charge part of the cycle.

[Ando]

I believe he already put it on the charger all night athomes still showing 14v.

[athomas]

Yes, but that information will help determine which part of the charger is bad. We know the charger is bad because the output is only measuring 14v. That is the same value as the output from the connector supplied by the cigarette lighter adapter. Even if left forever, the battery would never charge. Now, we just have to determine which part of the charger is bad.

[ArmyEngineer]

Hey man,
I've finally gotten used to the aroma of vaporized lead solder. My kids will probably turn out retarded. I'm and electronics engineer, so I can probably figure out what's wrong and fix it. The good news is that I have a working charger, so debugging the circuit shouldn't be too difficult. If you will pay for the shipping and the repair parts, I'd be happy to give it a shot. I have all the resistors it could ever need, but the electrolytic caps and ICs I'd either have to find at RadioShack or Digikey. The parts should definitely be less than $10. Let me know!

AE

[T-Bird]

Sorry folks about the late reply. Been a little held up.

Ive tried charging it all day and night. Still only 14V. I noticed that the charger will go from red to green for only about 10 minutes. I dont sit around all day checking it to see if it alternates, but anytime ive checked on it after 10 minutes, it is still green and never red again.

When i disconnect the charger then plug it back in, the same thing happens...red for 10 minutes and green forever (as far as i can tell).

ArmyEngineer, let me PM you. Id like to get my charger fixed up...but im torn since i was considering getting that lithium battery and charger from someone on AO that is 1/2 the weight of this one. I have to find the page again...all i remember was that he was saying the charger he designed was made to be indestructible.

Anyone know what i am talking about and/or have experiences with these batteries? Pros? Cons?

Hmmmm...decisions decisions.

[Ando]

The guy's been MIA for a while. And someone here has purchased his charger but went belly up and no one's been able to contact him.

[Tunaman]

If you keep jerking around and not get the right charger for the battery, you might end up with a fried board/new battery/both. Get the stock charger while you still can. These are almost gone. ;)