batter discharge slowly

when connecting battery after winter storage notice when connecting negative there is small spark can anyone point me in the right place to find problem is it rectifier or altenator problem ?

I would think that is normal, because your Swing has electrical equipment that is always on like the clock, trip meters, etc.

I was watching a YT video recently about a CBR600RR with electrical issues, and that bike was flattening the battery due to an internal short in the regulator/rectifier, which had to be replaced. Easy enough to disconnect that unit and see if the current drain continues. You can also try pulling fuses one a time while monitoring the drain.

I always expect a small spark when reconnecting the battery, bikes and cars. The leads should be attached with one firm, positive movement to the battery terminals because continuous arcing could cause problems.

i went to check the voltage today battery was full charge 3 days ago and now bellow 12 volts -2 today to cold to work on it would bad alternator discharge battery or would it be rectifier the culprit or bought trying to save myself from taking everything apart ether way i am looking at a big job

Are you riding it or it's just parked? Small spark is normal when connecting batt. Charge the batt. and leave it disconnected and measure the voltage again. Drops could be battery. Put a voltage meter on when it's running should be about 13.8 14.1 volts if it's charging properly give it about 1 minute after starting then measure it.

+1 on the mech 1
I had this problem on a Suzuki ATV. Found out Suzuki uses a positive ground system in it's wiring. I installed a kill switch but it didn't work. Researched and found out it was a positive ground and put the switch on the positive terminal. I switch it off when not in use and now the battery stays charged for up to 2.5 or 3 months. Good theft deterrent as well. Not sure if my 03 US Swing has a positive or negative ground system. I think the latter but don't quote me.

At the risk of stating the bleedin' obvious.....it's not that pesky under seat light is it?

Now that you mention it that's likely the cause of the small spark since one has to have the seat up to get at the battery. One would have to remove the light bulb from its socket to hunt for any other parasitics. I know by stupid accident that my SW will still start after two days with the seat not quite locked down. I have an LED installed but was still surprised it was lit for two days and the battery still had enough power to start the scooter.

this week i took off all the tupperware and tested all what could be killing my battery alternator stator tested good then went to rectifier had already had purchase one prior to my 2 reverse shoulder replacements witch was not in shape to tackle that at the time finally replace the rectifier and charging 14.5 volts took me 3 days to finish the project with 2 total knee replacements and 2 shoulder replacements working on a friends garage some here know how much pain you go through but the worse is taking off the tupperware cant sell a scoot that don't work and labour would be more then it's worth and love my PRECIOUS that's her name 130 k and 90 k on iridium plugs a no sign of oil burning on plugs cant beat synthetic oil . i want to thank everyone for all the help over the years been here since 2012 the best forum bar none ,great bunch of guys thank you for all your help . ( Mike) Tinman