Battery Woes

Charge the battery while disconnected from bike, as slow as your charger will allow, use the lowest output.
What is the DC voltage? Should be 12.7v or higher.
Install the battery in bike. Key off: What is the DC voltage? Key on: What is the DC voltage?
Hit the starter. A "good" fully charged battery should not drop below 10V for at least 10 seconds. If it drops below 10v in less than 10 seconds your battery is no good.
With the bike started, what is the DC voltage at the battery. Should be about 13.5v at idle.
Set your volt meter to read AC and check the voltage across the battery terminals. You should get less than about 4v AC, any more than that tells you your diodes are leaking.

Better yet; charge your battery and take the bike to a Auto Electric shop and have them do a AVR test.
To check for "AC ripple" you need an oscilloscope.
 
conundrum said:
...In my case, I typically have pulled the battery after about 2-3 weeks of no riding at the end of the season...bring it inside, top it up, and then let it sit on a shelf for 2-3 months...maybe topping it up again once or twice, and then making sure it is topped up before I reinstall it in the bike in spring. I use a CTek 3300 for both the car and bike in case that matters...
Click to expand...

This is what I do. I've been told that if the battery freezes it'll die. I used to leave the battery in my bike in my unheated garage all winter. This winter had at least 4 days of -17C or lower temps, so freezing is certainly possible. I take my battery out, ensure there is enough water, put it in my basement, and once in a while hook up my CTek to top it up.

Batteries are confusing. A bigger battery would be able to withstand more abuse but these 12Ah batteries are tiny.
 
I've always left the batt in the unheated garage. Sometimes it gets below freezing. Charge once a month for an hour at 2 Amps.(lowest on my charger). Has worked for the last few decades.
 
Left battery in bike all winter, unheated garage, no charging.

Brought it inside, charged it overnight (it was fully charged in less than an hour).

Put it in the bike. Vroom, vroom.
 
Once I thought that I had a bum battery in my HD Sportster. A little later on had the ground cable (goes from the battery negative terminal down to the frame/starter) break internally to the insulation. Near the lug on the lower end. I'm guessing that before it broke totally, it had high resistance, maybe affecting the charging of the battery or the current going to the starter.
 
I think I read somewhere a charged battery won't freeze unless the temperature drops insanely low (also why a car battery doesn't die when parked outside on a -20c day). A dead car battery however WILL freeze, hence why you only want to store it cold if it is sufficiently charged.
 
Hiya gents, update fer y'all:

After trying it on Friday morning and letting the battery sit all day, came home to find it at 12.8v (!!) put it back in the bike, turn the key and... It barely managed to get one crank. While it was in there, I tried a current leak test and my DVM read 0ma, so doesn't look like it's being drained by the bike.

Took it out, got it tested at CT and it's got a full 8 CCA! Wtf... I guess it's toast.

Exchanged tender for the Battery Tender Plus! One that nfq posted (thanks!)

Gonna give Ace Moto a visit since I'm gonna go grab a few other parts one time.
 
Kri$han said:
Hiya gents, update fer y'all:

After trying it on Friday morning and letting the battery sit all day, came home to find it at 12.8v (!!) put it back in the bike, turn the key and... It barely managed to get one crank. While it was in there, I tried a current leak test and my DVM read 0ma, so doesn't look like it's being drained by the bike.

Took it out, got it tested at CT and it's got a full 8 CCA! Wtf... I guess it's toast.

Exchanged tender for the Battery Tender Plus! One that nfq posted (thanks!)

Gonna give Ace Moto a visit since I'm gonna go grab a few other parts one time.
Click to expand...

Was there a warranty on the battery? I think you said it was new-ish and if it has a bad cell then maybe it would be covered.
 
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