extra motorcycle battery as overnight battery tender?

[darthmoto]

Hey guys, I recently moved for a new job, and am now living in an apartment with an underground parking structure. Unfortunately there are no outlets to be found. My 696's battery voltage will drop over the course of a week if I don't hook it up to a tender. I believe hooking up one of those 12v portable booster packs might be detrimental to the bike's battery, so how about using an extra motorcycle battery hooked up to the tender leads on my bike overnight? I would probably hook it up 2x a week and bring it upstairs to trickle charge it when not charging the bike.

Does this sound like a decent plan?

Thanks.

[OzzyRob]

I've been unable to ride for a while now and maybe have started the bike once or twice in a 2 month period.


What I'm getting at is that your battery is probably RS. And a battery that is RS can, by it's evil magic, make the charging circuit RS. Then that will entail potions and chants to summon A Lift. If said Lift is required when Bike Shop is closed you may have to summon Another Lift.

How are you going to go about limiting the current from battery off bike to battery on bike ?

[darthmoto]

It's not a bad battery. My work place is about 4-5 miles away from home. The problem with frequent short trips is that the battery doesn't charge long enough on the rides to fully recoup what was lost during cranking- over the course of a week.

RE limiting current from battery off bike to battery on bike, this is why I wanted to ask the forum. I'm not particularly knowledgeable about electricity, but would the 2 batteries not reach equilibrium and current flow stop? The other thing I can think of is running a maH controllable hobby trickle charger between the 2.

[OzzyRob]

It is a battery going bye bye....I had a job that close to home, over the course of the time I work there I rode 3 different bikes and never had that problem.....

One was an '81 CB900, this was an old cranky pregnant dog of a thing to start
One was an '88 GSXR1100
and the other was the wife's '91 ZZR-600

Shit when I was out of work I used to make 4 trips a day to the job centre, that was a 6km round trip and never ever had a battery discharge problem. Even doing short run courier work, constant stop start all day never had battery issues.

Something's amiss mate. I'd be looking further into it.

[suzyj]

You shouldn't need to leave the bike on a tender if you're using it that often. The bike clearly isn't charging itself.

[Howie]

As said, this is not normal.  You either have a weak battery, poor charging rate or a parasitic battery drain while parked.

Charge and load test battery, then check the charging rate at the battery.  13.5 - 14.5 volts across the battery at 3K RPM.  Less than that, go here;

To find a parasitic drain hook a meter with a milliamp scale between the batter +b and the battery cable.  Key off, see what the meter reads.  Any car spec is 60 milliamps. No official Ducati spec I know of, but I would expect less than 25 milliamps.

[SpikeC]

 If the bike has an immobilizer it will drain the battery.

[kokis]

not

[jaxduc]

It is a battery going bye bye

This.
I have the same bike as you and live 1 mile away from work and have never (knock on wood) had a battery issue in 4 years.
If I now have a battery problem I'm blaming it on you animatronik!