Ordered Rattan Challenger Pro. Received it charger would not plug into battery. Let them know 5 days later I get an adapter. The adapter plugs into battery. But does not charge. The LCD screen battery indicator well flash showing 0 bars. You touch the batteries in Decatur and it shows it has at least a half of battery.. anyway Rattan is sending me a battery because it's at least part of the issue that's not the whole issue. I say that because of the other malfunctions in the bike. Now while waiting on new battery. I've had plenty of time to do a lot of research on on batteries. I have figured out Rattan this issue. The plug into the battery itself has a very insufficient ground. The ground itself is only 2 to 3 cm very small so when you plug in it doesn't touch it and get a sufficient ground.. take a piece of copper wire about 1 inch twist it. And then flatten it with a hammer. Very carefully put it into the port making sure not to touch the center prong sticking out that's the positive. The ground is the little silver object you'll see underneath that PIN. Take copper wire foramen in a u shape going into the battery only touching the negative. Again do not touch the center prong it will spark can cause problems be careful. Holding that flatten piece of wire in the batteries porthole over the negative plug it in now you're negative will have a strong connection. And charge your battery it made my battery chargers light change from always being green to the red state of . what a beautiful thing. That's if you don't want to open up the battery and void your warranty. If you are past that point I would open up the battery and saw to yourself in a better negative connection and be done with it.