Hi all. I recently threw a cigarette lighter adapter onto my 2005 lowrider. It attaches directly to the battery tender plug and I use it to charge the phone on longer trips. I never used the battery tender in the past, so every time I get home now, I make sure to throw it on the charger to get the most out of my battery.

I noticed after 3 days of charging, my battery tender was still showing red. That morning, I went to start it after reconnecting the lighter and it sitting for about 10 min it wouldn't even crank...let alone turn over. Still had lights and indicators though. Hooked the battery up to a normal charger and let it sit for a day. That night and the yesterday morning, battery tender showed green.

Rode it yesterday. Unhooked the CL adaptor when I got to work and rehooked it up when I left for home. Bike has been on the BT Charger for about 15 hours and it still shows as red. Think the battery might be on its last legs?

 

Either the battery is about done or the Battery tender isn't working properly. I suspect the Battery tender because the regular charger seemed to work. Check the output voltage with the tender running (Battery Voltage). If it's below 13.2 the tender is probably bad.

 

Sounds like the battery is about done for. The actual charger is putting on a good "surface" charge the tender just can't do.

Doug

 

Check the battery voltage with the engine off, 2.2v x 6cell = 13.2v. I'd also check you're stator output - measure across the battery with the bike running - should be over about 14.5 volts.

We are talking about very small voltages here. A poor connection between the tender connection and your battery will drop a volt or two or more. In order for the tender to work it's potential must be greater than that produced by the battery. If there is a voltage drop (IR Drop) then the tender will not work - ditto for the regulator/stator output req'd to charge the battery when the bike is running.

 

I think the battery is about done. Even a quick 10 minute ride will take 2 days for the battery tender wall outlet to recharge the battery to green. The battery is about 5 years old...so likely is due to be changed. thanks for the input guys!

 

This is 100% good info.