Years ago I purchased a Coleman air pump to inflate our air mattresses. It is the kind that runs on battery power only. You plug it into the wall to charge it, but it doesn’t run off wall power. If the battery is dead, it won’t work, even if it’s plugged in.
![IMG_1165[1]](https://skpicky.files.wordpress.com/2013/08/img_11651.jpg)
Recalcitrant Battery
Last time we tried to use it, the power was reduced from gale force all the way down to three-pack-a-day emphysema. When I turn it on, it used to make a mighty noise, and now it just sits there and whines.
My old Air Pump.
I noticed that it has a lead acid battery, and I watched a Youtube video where a guy filled his lead acid battery with water, and he was able to recharge it. I figured I’d give it a shot, so I disassembled the pump and removed the battery. The battery didn’t take much water, but that’s neither here nor there. My father-in-law brought us a new model of the same pump, so the immediate problem is solved (how do we fill up our air mattresses at camp without giving ourselves an aneurysm?).
But I’m sitting here staring at the insides of this pump and I’m starting to wonder, what would it take to convert this thing to run off AC power? I think it’s a DC motor in there, but I’m not an electrician. Anybody know what it would take to make this conversion so I don’t have to use a battery? Is this even possible? Here are pictures showing what the inside of this thing looks like after I removed the battery: ![IMG_1166[1]](https://skpicky.files.wordpress.com/2013/08/img_11661.jpg)
![IMG_1167[1]](https://skpicky.files.wordpress.com/2013/08/img_11671.jpg)
Thoughts?
Words of Truth 
I have NO clue what ANY of this means. Or if it’s at all helpful. But I’ll share with you anyway. This is what my husband says:
We need to know the battery type. probably a 12v battery, but if you attached the biggest power supply you can find to it with the doshed line to the red cable it should work. he could probably use any power supply and just get different speeds if he bypassed the switch entirely though.
but adding water to those kinds of batteries wouldn’t do anythig. They’re designed to be sealed systems, and thousands to one odds say the the plates in the battery are either shorted, or worn away.
My wife suggested I reply to try to help out. You can possibly use an AC to DC converter. You need to determin the voltage of the battery first. This is hopefully on the battery itself–it may be different than the voltage of the charging adapter (it should be slightly lower than the original charger output voltage). The next step would be to determine the current or amps. If you are lucky, there might be a rating on the motor indicated by a number followed by “A”. Otherwise you would have to use an amp meter WHILE it is running with a good battery. If the replacement you are using is the same model you could check the amps on that as well. Then you have to get a power supply with the correct amperage and voltage. The voltage should be exact, but the amps of the supply just need to be equal or greater. Don’t worry about the shape of the output plug on the supply. Cut it off and wire it direct to the battery leads. If everything is sized correctly it will work great and never need another battery. I have successfully done this with numerous infant and toddler devices. If the amperage isn’t too high, you might get a supply at Radio Shack, but it may be hard to find one or it might be too expensive. If it is 6 or 12 volts, you can use a motorcycle battery available at Walmart or other store. Once again, kind of expensive and yet still battery powered but now you would need a cord attached to it at all times. Sometimes it’s just not worth salvaging old equipment. Hopefully that helps and is t just a bunch of mumbo jumbo. Good Luck !!
Thanks! I might give this a shot if the parts only cost a few bucks, but I’m not buying a motorcycle battery. I can purchase a new Coleman air pump running off AC for $25, so if the parts to make my own cost more than that, it’s not worth it.