Emag power ?

[fishmishin]

Okay this is the setup:

UL emag lowers
X valve
Xmod 1.7
KC battery
Stock charger/ enercell 12v wall charger

Problem:

I am getting really bad battery drain from somewhere.

1- Charger is putting out 24-25v

2- When charging the battery, it charges for an hour or so / red light, then switches over to a green to trickle charge. Leaving it on charge for 4-6 hours.

3- After charging the battery I am only getting 14.8-15.24v, the highest I have seen it go is 15.9v.

4- When I install the battery on the marker and pull the pin, I test it from the one wire of the solenoid(+) which is also where the red wire is soldered on the back of the PCB, to the board screw(-). After pulling the pin I can watch the voltage drop all the way down to 12.9v. If I take the battery off the marker and test it the voltage will slowly rise back up to 14v.

I'm not sure what is going on here. I just got this battery recently. Also I borrowed battery from someone and the marker functioned fine with it, but not the new battery.

[kcombs9]

if its a KC battery Id PM him and ask. It sounds like the battery is shot to me you need at least 14v for the gun to function, most emag batteries test at 18-19v+ when charged.

[athomas]

That low battery pack voltage indicates a bad cell.

[fishmishin]

Hopefully it isn't a bad battery, I am wondering if it is actually a problem with the charger shutting off to early.

[fishmishin]

Okay fellas, after doing some testing tonight I have discovered it is the charger that has gone bad. Here is how I came to this conclusion.


I have a Guest 3 Stage Automatic 24v battery charger M#26015-24 that on the primary stage charges at 21v. What I did was use the old battery pack that I thought needed to be replaced, hooked it up to the 24v charger with some alligator clips and let it sit on charge for 20 mins. My initial reading on the battery before charging was 5.6v, and after charging for 20 mins it gave me a reading of 19.58v. All readings were taken from my Fluke 77/bn that was calibrated 3 months ago, courtesy of my brothers employer :D, After hooking it up to the emag and taking roughly 300 shots I took another reading and the old battery still had 18.3v, this is also running the warp feed hooked up with a warp interface cable. I haven't tried charging the new battery that I have because I didn't want to risk damaging it. I did get with Roman today though and had already ordered a rebuild kit for my existing charger, which should be here by the end of the week. So I'm planning on just waiting to rebuild my stock charger to charge the new battery

[athomas]

You are extremely lucky to get the old battery working with a 5.6v starting condition. That is well below the knee voltage of a dead battery. Below this value, the cells do strange things and the electrodes have a tendency to build up a barrier that prevents proper charging.

[Tunaman]

Hooking it up to a high power charger may have disloged the poultergeist chrystalline life forms that live in your battery. That battery may be good to go now. I have tried the welder trick on a few and it did work...for a while.

[fishmishin]

It kinda surprised me to. I shot it some in the back yard today, and it was still holding 17.6v running the warp, revy, and the emag. I need to get some new shrink wrap for that battery, I cut the shrink wrap open months ago when I went to the battery store to see how much it would cost to have them build me one. I wanted it for that weekend, but not for the price they wanted. At least I have a couple, with cases now, just in case I need one for some strange reason.

[athomas]

Hooking it up to a high power charger may have disloged the poultergeist chrystalline life forms that live in your battery. That battery may be good to go now. I have tried the welder trick on a few and it did work...for a while.There is lots of discussion on different battery forums on this very phenomenon. Apparently you can pulse charge a battery at higher than normal voltage and dislodge the sulfates(or whatever oxides are present depending on battery type). It is disputed by others, but I think it is just because it is not consistent and depends a lot on how long the battery has been allowed to accumulate a deposit on the electrodes.

[fishmishin]

Well maybe I got lucky on this one. Supposedly the battery was charged well when the previous owner received it and once it went dead he couldn't get it to charge with the stock charger. From what I understand it was January when he had used it last. I picked it up from him in February, and I had tried to charge it a couple of times with no success. With the charger putting out as much voltage as it was I just assumed that the battery was not taking the charge, and had gone bad, it was also what I was told when I bought it, that it needed a new battery. Then when I got the new battery and it wouldn't charge I thought maybe I had received a bad battery, and I was sent another one, no questions asked. Then it wouldn't charge, so I started thinking about the charger a little more, I had a hard time believing I received 2 bad batteries in a row. I know after shooting it some yesterday, I checked it last night and it was still holding a charge.

Does anyone know what part on the board of the charger would cause it to shut off early? I have a rebuild on the way, but if I could fix the one I have to have a back up it would be nice.

[Hobbez]

There is lots of discussion on different battery forums on this very phenomenon. Apparently you can pulse charge a battery at higher than normal voltage and dislodge the sulfates(or whatever oxides are present depending on battery type). It is disputed by others, but I think it is just because it is not consistent and depends a lot on how long the battery has been allowed to accumulate a deposit on the electrodes.


Having spent many years in the radio control hobby, some of it competing at a national level, I've dealt with a lot of batteries over the years. When packs used to get weak, I used to disassemble them down to the individual cells and "super" charge them using as much as 90 volts to charge a 1.8v battery. Most tracks I raced at had machines that did this for 4-5 cycles and would then spit out a new set of labels listing the new voltages and capacities. If your having battery problems, the best place to go is your local RC store and ask if they can point you to a conditioning machine. I've never been in a battery store that new there *** about batteries.

I can't speak to the quality of AGD chargers, I've never used one. I can speak of the quality of top line RC chargers and how spending a little extra on a quality one can save you a ton of money. When your spend $300 each on batteries so you can win, you want it charged the best it can be :p

[fflamingmoe]

I've had this happen alot but what do is called a cool down.
When i charge my batteries in my E-mags the batteries feel hot.
Then i let them sit to cool off,and it works with batteries that people think are dead.
If they are too hot it can do funny things to the electronics and could fry the boards.
Just don't put you battery in when hot and it should function properly. :cheers: