I have a IP 3800 2S Lipo which I charge with a Onyx 230 at 3.8A. When I start the charger the In Volts should work there way up to 8.40v then the amps drop off till complete. Lately the Volts start to climb to 8.4 but before they get there the Volts start to drop off then climb back up. Im guessing it could be because of a bad cell but its only a guess. The battery dosn't get warm and no noticeable swelling. Any ideas. And I do use a Ballancer. Thank you.

Could be a connection thats making contact and then briefly loosing contact. Are your bullets in good shape and getting a good grip? some bullets need to be "re-sprung" every so often.

I think anything that interrupts the charging process will make it repeat like you're seeing.

Posible internal battery problem I have a 5000 Thunder Power Lipo and it dosn't seam to have the Voltage Drop/Jump that the IP dose and I forgot the Amps will jump around too but it dosn't seam to be a problem running the car.

Your lipo is hard cased and uses bullets? The bullets are connected internally to the lipo cell tabs, might have one connection getting flaky. Or your bullets are loose in teh plugin on the batt. Anything that interrupts the current, for even an instant will make the charger think its starting a charge again. This is not something thats normal or expected in charging, but if it charges, doesn't get hot and discharges (runs) OK, then use it.

I didn't say its bad. It prob just may be showing signs of age and use. If its a connection doing this, eventually it will fail and need to be fixed or the lipo replaced.

Thunderpower is a better quality lipo. I know my IP 5000s were way cheaper than my Neuenergys.

The battery is 3 months old but like you said from pushin and pulling on the jumper it could of loosened up the tabs in the battery. Is there a way to fix it with out causing bigger problems.?? I'm guessing the case is glued together and I don't know about soldering on open cells

Not really, opening the case is one thing, but if its the connection to the cell tab, that requires zinc solder and zinc compatible flux, some really nasty stuff.