This may sound really bad...but I'm trying to understand how to charge my battery on my 07 sportster. The battery is very difficult to get out from what I can tell and from what I've already tried to take apart.

I just want to put a slow trickle charge in it. The positive side is fully exposed, but the negative is impossible to reach without figuring out how to remove the whole damn thing.

With that said, can I just hook up my charger to the positive side, and then the black wire to the frame, or does it not work like that?


Thanks in advance guys

 

That works just fine.
I would stay away from Trickle chargers though, if you leave them on too long you'll cook the battery.
What you want is a Float charger, often referred to as a Battery Tender. (Google it)

 

^^^Yep^^^

Just connect red to + and black to good spot on frame for black (-), or find other end of ground under bike (where it bolts to frame). Should do it...

 

like this? It has 12.13 volts in it now...but figured I'd give it an hour or so on 2amp?

 

Yep, that works, but you could also use a bolt on the motor so you don't have to remove the seat.

Without looking it up, 12.15 volts is only around 30% charged, so you may need more like 6-8 hours @ 2 amps to get it full (12.8V).
Up to a 2 amp rate is fine, but for good battery life, I don't recommend using any higher rate.

 

These are available at Walmart, dealers, amazon, etc. A good $25 investment.

 

I use a battery tender jr. got it brand new on e-bay for $17.50..it is a float charger and works very well,,,it comes with a small harness you put on your battery and the other end has a plug,,,just plug it in and your battery is always ready to go,,,

 

Thanks guys! I will look into a tender. I never do more than 2amps. I'd rather do like 0.5 amps but for that I'm sure I need a tender.

Thanks Charley for that voltage breakdown...I had no idea

 

Your battery is rated at 20Ah, so at 30% charge your at ~7Ah and 14Ah low.
A 2Ah charge x 7 hours = 14Ah.
To check the charge state of the battery when charging, remove the charger, turn the ignition on for 10 seconds (lights on, no start), turn ignition off then measure battery voltage. Turning the lights on for 10 seconds depletes the "false" over-voltage surface charge on the battery left by the charger.

A full charge is 12.7 - 12.8 volts.

 

I'm a big fan of the Battery Tender option. I have three bikes in the garage and they are all connected to tenders all the time. The harness is hidden between the frame and seat on my sporty so it's not in the way. It appears that the new Harley's all have the harness as a standard now.

Gonna be raining for the next two weeks, it is times like these that I'm glad they are connected to tenders.