Those fiber pads I linked to should be okay to clean the contacts on the C4-12, just use very light pressure in case those contacts are coated with a thin layer of protective metal.
Ok will do thanks
Yep, pencil eraser works well as does Scotch Brite. Rubbing them on your pants leg will work to.
Haha I’ve been doing that for a while thinking nobody else did that for a good while!
Thanks for confirming I’m not too crazy teacher 
My pleasure Mikeadoo…. :+1:
Nope… you are not alone. 
Eraser work for the charger as well?
I’ve never used an eraser.
Okie doke. Fiber pads it is then. I tried eraser on charger. Didn’t seem to do anything.
I’m going to be in the minority it looks like, but I would not use scouring pads on the charger, many of the contacts could be plated, and you are just going to create scratches that will more easily collect and retain contaminants. Use Isopropyl alcohol, or specific contact cleaner.
I would not recommend scratch pads on the battery either unless you are trying to prepare the surface for soldering or something, and the metal/plating is not suitable.
thanks. Rubbing alcohol best?
Isopropyl alcohol is really weak at cleaning, in my opinion. It doesn’t hurt to try, though. If you want a chemical only type cleaner and didn’t care so much about getting the lowest internal resistance readings from the batteries, then I would use something a little stronger. You can put a little lacquer thinner or carb/brake cleaner on a clean rag or paper towel and then rub the contact points. These are strong chemicals and are flammable so they have to be used with caution, obviously.
Electrical contact cleaner is a pretty specific product that not many people are going to have, plus it’s a little on the expensive side. I’ve got some and I’ve used it a little bit, but never tried it on the ends of a battery. Again, you would want to squirt a little on a clean rag or paper towel and then rub the battery ends with it.
Tomorrow I will try this out and report back if it actually does a good job of cleaning or not.
Use Isopropyl 99.9% alcohol, you’re not cleaning the floor. if you need something stronger because of oils or grease contact or contamination due to bimetal reactions or plating wear try a contact cleaner or something like Deoxit. Some those others could strip the plating right off and have their own contaminants, they are not to be used for electrical work.
ps… consider the accuracy of the measurement and the system. if you want precise IR measurements you probably should start with better contacts.
Ok standard battery and Jason I’m looking to clean the charger and if need be the cells. They’re gonna need it eventually.
I have not tried anything but a pencil eraser on the charger. I’m getting a little confused and I haven’t googled what each of them chemicals are that were mentioned above. All I know really chemical wise is what I use at cabelas for maintenance work (spitfire mainly).
But I really doubt that will work with any of this stuff.
I don’t know what deoxit is but I will try my best to figure it out on the world wide web.
I’m not looking for the absolute lowest internal resistance, I just want to get my Sofirn cell under 134 mohms.
Thanks guys
The C4-12 is definitely not the best way to measure IR.
Does anyone know a more accurate and precise way of measuring a batteries IR?
Can you just hook it up to a DMM?
I’ve never actually tried that. I don’t want to fry my meter. Lol
What’s a DMM?
I’m guessing some kind of multimeter?
Yeah, digital multimeter.
Do you know what the Sofirn cell is under the wrapper? Does it have a button top? What makes you think it will ever measure less IR than what it is currently?
I do not know what cell it is under the wrapper. I dont know what I’d use to get the wrapper off without damaging the cell. Button top yes and i honestly dont know if it will measure less IR or not. All i do know is that it is now doing what my 30Qs were doing with the crazy IR in this charger.
That is why i am asking on the forum. Do i just use my small box opener to cut open the wrapper a little then peel it off the rest of the way? Exacto knife really. Not a box opener.
I used to be getting IR of 60-85 IR but now its way higher
No, do you even have a new wrapper to put back on it?
It’s possible the original wrapper might have been removed anyway to keep it from getting too fat in diameter.
When I say “the cell under the wrapper” I don’t mean to cut off the current wrapper and look. You typically have to do some online research or maybe ask Sofirn. Surely somebody on BLF knows.
I think your worrying over nothing. What light do you use it in? Is it noticably dimmer?
Maybe you should stop using your C4-12 to measure IR. Surely there is a better way to measure it.