Hey everyone.

Let our Road Glide sit for a few months without the batter tender on it and now it won't start.

We put our Battery Tender Plus (link for specs) on it for the last couple days and it basically shows a solid red light and green blinking light - which indicates that it's charging and the battery is greater than 80% (source). I don't believe this is accurate, since I tried to start it last night after a good 2 days on the charger and it barely turned over a few times. The headlights, screen and everything turns on - no clicking on startup. I don't think it's fully dead, I just can't seem to get enough power to it to get it running. It's definitely very very low.

Before just assuming the battery needs to be replaced, do you have any other advice or things to try? Should I try hooking up the tender using the clamps, in a location other than the existing adapter connection? For now, planning to just leave it charging. I was reading that some people use a 3V charger, as the battery may be dead to the point that a Tender Plus won't be sufficient to get it to a certain voltage. Any recommendations on a good battery charger, or whether that's the right solution? Or should I just remove the battery and take it somewhere to get tested?

 

I would take the battery out and get it tested

 

Put it on a real battery charger. A trickle charger is not really made to charge a completely dead battery, more to top off a partially discharged one.
If that doesn't work then take it to be tested. It will need to be fully charged to be tested anyway.

 

Isn't it under warranty?

 

Read what the maker of your AMG glass mat battery says. Usually it's below 1 Amp. And it is going to take 24+ hrs . Depends on reserve CCA capicity. People have all types of ideas. Make sure your connections at the battery are tight. It has to be charged to check what CCA reserve is.. (except of course for a ground or such that just comes back bad battery)
My experience around here is most checkers do not work well with small batteries.

Quit trying to crank it till you get 12.7 volts or so on it with the headlights flipped on and then off to kill charger surface charge of about 14.6) The volts should not drop below 9.6 DC when cranking. You need an AC/DC/OHM meter.

 

Any recommendations? I saw a few people recommend the NOCO Genius G3500 6V/12V 3.5A ( ) in a similar thread.

It might be, but I'd have to get the bike there first, unless I just pulled the battery. I do have to take it in for a recall service, so if I can get it running I may let them know what's going on when I take it for that to see if they can just double check everything at that point.

I'll have to get to the battery tonight and check it out. Have done some battery and/or rectifier replacements on my previous bike (Street Glide) but haven't done much to this bike and would have to get familiar with where things are. Not too familiar when it comes to dealing with electrical systems, unfortunately. I will check the voltage next time I turn the headlights on, that would be a huge help and I didn't even think to do that. I remember when I had electrical issues with my Street Glide, I watched the voltage drop from about 14 to 12 while on a ride. I'll keep an eye on the 9.6 when cranking (once over 12.7). Any other tips would be appreciated. Should I leave the tender on for 24+ hours, or try an actual charger like I linked above? ( )

 

I have two of the Noco 3500 charger/maintainers for my bikes. Used one to bring back to live a battery that was dead on my 2012 Lexus.

 

Did you have to buy the plug/adapter separate, or do you just use the clamps?

 

I bought the SAE adapters for both.

 

That was on with lights, then off to check charge state at 12.7 or so (+/-0.1 volt) (12.3 is 50% charged)

Long as you have a digital modern charger that cuts back, guess it is OK for your charger.
I am just quoting what the manufacturer says.
When you draw a battery way down and highly sulfated, it needs to come back at a low amp level very slowly.
Harley gel mat battery says any charge over 2AMP will shorten life even if on automatically control controlled charger.
I have a Bell and a Harley maintenance charger. Both are less then 1 AMP.

Problem I see here is say battery is not down a lot, so you hook up the 3AMP charger, since voltage is controlling output, it is going to throw 1 AMP at it. However, if battery is very low, then it is going to hit it with all it can.
I could be wrong here. I am just quoting book. Not what grandpa said.
I have an old 12 AMP charger that puts out voltage even if not connected. I use it to check fuel injectors spray. Also have a so called digital 12AMP one that puts out nothing unless it reads battery.