I've had my 2006 Softail Heritage on a Battery Tender Jr. since I bought a new Deka battery about two years ago. Last week, I went to start my bike and all I got was the dreaded clicking sound. I used my multi meter to check the battery voltage. It was down to 11.52 volts, meaning it was below a 30% charge and therefore dead. The light on the battery tender was green. I checked the in-line 7.5 amp fuse on the pigtail of the battery tender and it was blown. I inserted a new 7.5 amp fuse and it immediately blew. There was a very slight spark when I inserted the fuse. I can understand that with a blown fuse, the battery tender could not maintain the charge on my battery. In my opinion, the internal mechanics of the battery tender should have detected the blown fuse, and turned the light to red, to indicate no maintenance was occurring, but apparently that is not how this battery tender is programmed. To complicate things, my battery will not retain a charge. It goes from 13.4 volts all the way down to 11.54 overnight. It keeps doing that every day. I think I now need a new battery, but why? Why would a new battery only last two years when on a battery tender, and what would cause the fuse on the pigtail to blow (wires are okay?

 

 

I've carefully visually inspected the entire pigtail and found it intact. No breaks. I also used a multi meter to do a continuity test of the positive and negative leads. It has good conductivity.

I did forget to mention one very important thing in my first posting, and that is that even with a full charge of 13.XX volts, it would not start the bike, and I would still get the loud click. That alone tells me that the battery is no good. I did that several times with a full charge, and got the same results, so at this time I see no need to recharge the battery again, and perhaps it is indeed time to go buy another battery. Just a word of caution to all, don't fully rely on your battery tender when you see the green light, as it may not be charging at all, so check the in-line fuse. Thx.

 

If you didn't look to see what the battery voltage dropped to under cranking, you have not verified it's the battery and not something else. Also, check continuity between the + & - legs of the tender pigtail unhooked from the tender - they should not have continuity between them.

 

 

Yesterday, I removed the battery from the motorcycle and charged it to 14.2 volts. The next day, while standing alone and fully disconnected,
the voltage was down to about 12.7, then after a few more hours, it was down to about 12.5
I recharged the battery again and placed it back on the bike. I attached a multi meter to get a reading under load. When I tried to start the motorcycle,
I again got the loud clicking and the voltage went down to 7.4, then to 4.7 while cranking.
Does this indicate by battery needs replacing?

 

YES! That is one killed battery. It should not drop below 8.4V while cranking. Charging the batt to 14.2V is not good for the battery either, when you do that it will taper down to about 12.5V which is where you want the static voltage to be.

 

Thank God for fuses? It could have been much, much worse.

Your battery sounds very suspect.

 

You likely have a short inside the battery.

Very simply, I would have attacked it this way: see fuse is blown, replace fuse and try tender on known good battery. All good? Put tender on suspect battery. Fuse blows? Replace battery.

 

No posts on this for awhile...hope some are still following though...

I recently bought a 2016 HD 750 Street. Battery tender connection on the bike shows 0 volts. I can hook up battery tender to know good battery and it charges. I removed the seat...but can't see where the pigtail traces back to the battery (to find the inline fuses I heard about). I don't want to just start yanking on wires and connectors and things...but what's the alternative? take it to the dealer and get charged $$$ to look at it? I really don't want to go all winter (in MICHIGAN) having to start it every few days and let it run to keep the battery charged...but I certainly DON'T want a dead battery!

What to do?