I have a digital camera at work and rechargeable batteries for it. I leave the recharger out in my office so anyone who needs to use it can. Unfortunately, I found out last night that someone put regular batteries in the recharger–and they leaked. I threw them out but there’s some corrosion on the recharger now. Can it be saved? Do any of you smart, techie Dopers know how (or if) I can clean it?
Don’t bother. The current overload very likely destroyed the charger, and even if it didn’t, some internal components may have been stressed past their tolerance. The unit is now a potential fire hazard, if it even works at all. Toss it out and buy a new one, they’re cheap enough.
You can try but it will at least contunue to give you problems such as bad contacts and battery corrosion.
Best advice, get a new one.
I’m not sure if you can clean it, but it is possible the recharger still works. There are two potential problems. One is that the metal contacts are corroded; the other is that the overheating, and leakage damaged the electronics. If the electronics that make sure the current flow is proper for your batteries are damaged, you might not know. I would make the moron who put regular batteries in buy you a new one. (Of course, it is probably your boss.)
Well, only one of the contacts has any corrosion on it. I used a toothbrush to clean off the other contact that had a bit of corrosion on it and that seems to have worked nicely. The recharger did work again–I had a few old batteries (rechargeable ones this time) to throw in there to see and it seems to be working–I just wasn’t sure it was advisable to keep using it after this had happened. I also hadn’t realized the fire hazard potential! I’m going to order a new one–hopefully I can get one soon.
Thanks for your input, everyone!
my friend told me his granddad used to recharge nonrechargeables, until one day he left them in to long and BOOM!! i presume up intill the charger exploded it must have worked fine. btw he was an electrician, he used to build different types of radios for a hobby,
An electrician did that?! :smack:
Now I don’t feel so bad that a bunch of librarians didn’t think to read the batteries before slapping them into the recharger. 
I built a recharger for non rechargable batteries when i was at school from the maplin catalogue. It worked quite well. I seem to remember it used some modified version of an AC current to recharge them.
Whaa…? Batteries are always recharged with DC. The ones that plug into the AC outlet use rectifiers and filters to supply a smooth DC current to the batteries. Regular alkaline batteries can recharge a little, but the chemical reactions that create the electrical flow are not very reversible, so the effect is very tiny compared to the capacity of a new battery. Also, the low internal resistance of alkalines means that the current is high, and overheating quickly leads to further electrolyte breakdown, with the potential for fire. So, don’t do that.
That’s interesting, but I generally prefer to purchase my tech toys–I’m not so hot on the building part.
He may have been talking about the old Carbon/Zinc batteries. They could be recharged to some extent.
There are also rechargeable alkaline batteries available. They require a funky pulsed charging current, and one of the simplest chargers uses what could be described as “modified AC.” The cheap chargers for the rechargeable alkalines have a current limiting resistor coming out of the transformer, and a half wave rectifier. There’s a Zener diode in parallel to the battery to limit the charging voltage. The Zener, together with a properly selected output voltage from the transformer, truncates the half sine wave into the trapezoid pulse that the battery needs.
Rechargeable alkalines perform as about well as normal alkalines for the first use, and not as well as typical rechargeables after that.
Always use the proper charger for the battery, and no charger on a non-rechargeable battery. But then, you already know that.
Ah, that modified AC you’re talking about is referred to as pulsed DC. It’s used in rechargeable alkaline systems to lower the duty cycle so overheating doesn’t occur. Those rechargeable alkalines are pretty crappy, though. I’ll stick with NiCds or NiMHs.
Yup. I’m not advocating the silly things, either.
Yes, “pulsed DC” it is. It was the only thing I could think of that matched mooka’s description of “some modified version of an AC current.”
My brother does this in my charger all the time, somehow he manages to put in two NiMh and two alkaline batteries. No leakage (yet).
Personally, if it still works, I’d just keep using the charger.
Thanks for the advice, everyone. It doesn’t seem too bad so we’ll use it until I can order a new one–just to be on the safe side.