Battery discharge?

[2000daytona]

Good morning - I have a new battery (placed in motorcyle in October 2010) in a 2007 ST1300 and had no issues until yesterday. Went to start the motorcycle and it barely turned over and would not start. Had not ridden it for two weeks. I placed a Battery Tender on it and it seems OK. Has anyone experienced this? This is the first time that this has happened and I have been riding every weekend or every other weekend where possible. My concern is that it does have a LoJack on it and maybe this is causing the problem. Time to get rid of the LoJack? Not sure why all of a sudden the battery is discharging. Any comments would be appreciated. Regards.....2000daytona.

 

[Avtrician]

If you can, measure the current draw of the lojack, this will allow you to calculate how long the battery (about 12 amp hour ithink) will last. You probably havent been riding the bike long enough each time to replace the used capacity. You probably will need to connect up the battery tender each time you park.

 

[Pepe']

The quick test is to put a volt meter on the fully charged battery and see how low the voltage drops when you try to start the cold engine. If the voltage drops below 9vdc then I would say you have a bad battery. It really should not drop below (roughly) 11.5vdc for any reason.

Or you could take it to Advance Auto/Autozone to have it more reliably tested. It would not be the first time a new battery crashed.

If the battery checks out, then maybe the starter is drawing too much.

Or, as Avtrician suggested, there could be some battery drain that is killing the battery. That involves a bit of poking around and measuring electrons in the harness and eliminating various electrical items to see if it effects a change.

 

[st1300r]

1st thing to do is get the tender on it to get a full charge.
Make sure both ends of the ground and + to the battery are clean then dielectric grease and retighten.
Then I'd checking the voltage when cranking. Should be above 10v.
Out of curiosity what brand of replacement battery? I had a Bat+ one that lasted 1 month.

Have you checked the current draw on the battery when the bike is off?

Don't know what the LoJack draws. fwiw oem battery is advertised as 11.2 Ahr.
1ma is negligable.


From lojack web site;
Where does the LoJack get its power from?
The unit obtains its power from the motorcycle's battery. The LoJack unit also has a back-up battery.

How much power does LoJack drain from my battery?
One milliamp on average.

Will the LoJack drain my bike's battery?
As with any powered accessory, the LoJack unit will draw power from your battery. We recommend that all motorcycles that have a LoJack installed also have some type of battery maintenance device installed such as a smart charger or trickle charger for periods of infrequent use.