Ducati.ms - The Ultimate Ducati Forum banner
  • Hey Everyone! Enter your bike HERE to be a part of this months Bike of the Month Challenge!
1 - 12 of 12 Posts

·
Registered
Joined
·
56 Posts
Discussion Starter · #1 ·
I built my 996 back in '08.It has ported heads,13:1 Pistals,SPS cams and custom map.THis is the second Yuasa lead acid battery to do this.I also have upgraded battery cables.It takes two seasons each to happen.THe terminals always seemed to be loosening.But i notice the terminals are degrading.I THINK the initial draw upon starting creates enough heat at the terminal to SLOWLY melt the lead.I have already performed a diagnostic with my Mathesis kit and the charging system seems fine.Back when the engine build was completed,Kyle at BCM suggested one of those fancy Lithium batteries.I think the suggestion was for increased CCA.I also wonder the terminal material may not be lead in these.Suggestions? Has this happened to you?
 

·
Registered
Joined
·
2,051 Posts
13:1 compression is going to draw significantly more current than stock. The terminals on the lighter weight lithium batteries seem to be more robust to handle their increased capacity for higher cranking amperage.

The thicker cables also allow for more current draw and thus put more stress on the terminals and battery as well. Not surprised to hear you've got issues with the battery considering the higher compression and thicker cables.

Ballistic's and Shorai's or something similar are probably the way to go here I would think.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #3 ·
Yeah,the bottleneck now seems to be AT the terminals.I can easily get a season out of a stock battery.Lately it has gotten worse as this is late in the second season.The other night they were silly loose after a ride.THe nut is about to break thru the lead terminal.
 

·
Registered
Joined
·
1,007 Posts
I had the same problem with my 900SS with 944cc HiComp pistons. It would get so hot that the cables would actually smoke. :eek: On my bike it was due to the POS stock cables having so much resistance that it would get hot enough to smoke. :rolleyes: I installed the Motolectric kit and I have had no problem since. :)
 

·
Premium Member
Joined
·
3,494 Posts
Yeah,the bottleneck now seems to be AT the terminals.I can easily get a season out of a stock battery.Lately it has gotten worse as this is late in the second season.The other night they were silly loose after a ride.THe nut is about to break thru the lead terminal.
If you're going through a battery a year, you're doing something wrong. Ditch the old flooded electrolyte one and get either an AGM or a lithium-iron unit. And buy and always use a decent battery tender. Plug it in every time the bike is parked at home and during the winter, and you'll get long battery life.
 

·
Old Wizard
Joined
·
3,007 Posts
Replace the Starter Cables

At startup, the wires to the Ducati's battery will initially draw in the neighborhood of 200 amps. (That's a lot.) This is for a stock engine, a higher compression engine will draw this current for a longer period of time.

If you crank it constantly for say a half a minute, and do this several times in a row without letting the motor and wiring cool down, you're going to get overheated wires, even if all of your connections are good. When the wires get hot enough the insulation will start smoking.

Thats why Owners Manuals recommend that you crank the starter motor for only five-seconds at a time, with a ten-second wait in between.

If the wire connections are loose or corroded, they are an additional source of higher resistance and heat. If a battery connection has a small resistance of say 1/2 ohm, a typical starting current of 45 amps generates over 1,000 watts of heat, more than a toaster. The initial draw of 200 amp through a 1/2 ohm resistance at a corroded or inadequate contact area connector is 20,000 watts. That's why the battery terminals are being overheated.

As the starter cables age, the tinned and crimped junction between the wires bundle and the connector itself corrodes and becomes the point of high resistance. So a replacement starter cable kit that uses a larger gauge wire is a good solution to your problem. Also, look for a replacement battery having terminals that offer a large contact surface that will make a more secure connection with your cable terminal configuration.
 

·
Premium Member
Joined
·
331 Posts
At startup, the wires to the Ducati's battery will initially draw in the neighborhood of 200 amps. (That's a lot.) This is for a stock engine, a higher compression engine will draw this current for a longer period of time.

If you crank it constantly for say a half a minute, and do this several times in a row without letting the motor and wiring cool down, you're going to get overheated wires, even if all of your connections are good. When the wires get hot enough the insulation will start smoking.

Thats why Owners Manuals recommend that you crank the starter motor for only five-seconds at a time, with a ten-second wait in between.

If the wire connections are loose or corroded, they are an additional source of higher resistance and heat. If a battery connection has a small resistance of say 1/2 ohm, a typical starting current of 45 amps generates over 1,000 watts of heat, more than a toaster. The initial draw of 200 amp through a 1/2 ohm resistance at a corroded or inadequate contact area connector is 20,000 watts. That's why the battery terminals are being overheated.

As the starter cables age, the tinned and crimped junction between the wires bundle and the connector itself corrodes and becomes the point of high resistance. So a replacement starter cable kit that uses a larger gauge wire is a good solution to your problem. Also, look for a replacement battery having terminals that offer a large contact surface that will make a more secure connection with your cable terminal configuration.
Good points. I wish this was made clear more often.

A few notes:

While you may see an initial peak of 200 amps- say for .25 of a second- once the crank starts moving the load decreases a bit. Sustained output over a 5 second start sequence will show closer to 100 amps than 200.

However- passing 100 amps through an 8 gauge battery cable, and a tiny terminal for more than 5-10 seconds on ANY battery is going to cause it to overheat.
The solution here is likely a few things:

Figure out why the bike doesnt start immediately and address that. I would guess it is mapping, as that is almost always the cause of poor starting on otherwise well maintained bikes. Once the mapping is sorted, you wont need to hold the starter button for long periods of time.

Getting a proper battery is always a good idea as well. A well designed lightweight battery will have all of the attributes that Shazzam pointed out- large terminals, etc...
Our battery terminals were designed specifically to address these issues. Id suggest you look at them for a solution.

Lastly- leaving a lithium battery on a maintenance charger for the entire winter is not only a bad idea, it is unnecessary.
If you are not going to use your bike for 4 months, just disconnect it. It wont lose any charge if it isnt connected to anything.
On the other hand, leaving it plugged in to a battery "tender" type device- even one designed for a lithium battery- is not an efficient way to store a battery.
 

·
Registered
Joined
·
56 Posts
Discussion Starter · #8 ·
Thanks guys.I already have big cables from Cogent Dynamics.my map was given to me by Kyle at BCM.it was for the same set up EXCEPT for 4% more displacement.the map came from a 1036 kit or 100mm instead of my 98mm pistons.it does start w/in 5-10 secs.but initially drags until momentum allows engine rotation.I think I need a fancy battery.Mr. Spectrum,I'll be in touch.
 

·
Old Wizard
Joined
·
3,007 Posts
Running Smaller Batteries

In 2001, all the superbikes were fitted with a revised starter motor gear ratio that draws less current and made it possible to start the bike using a smaller OEM battery. That’s when Ducati started using the smaller gel battery on their bikes.

The starter gearing on the MY 2000 and earlier bikes like yours is not well suited to the smaller batteries. The starter motors draw too much current during starts.

The limiting factor for using smaller batteries is that they have limited reserve capacity for prolonged or repeated start tries. Their lighter weight certainly has a place on track bike but may not be reliable in colder climates or when used on high compression engines on the street. I understand that the new Panigale has a compression release to reduce current draw when using a smaller OEM gel battery.
 

Attachments

·
Premium Member
Joined
·
331 Posts
Thanks guys.I already have big cables from Cogent Dynamics.my map was given to me by Kyle at BCM.it was for the same set up EXCEPT for 4% more displacement.the map came from a 1036 kit or 100mm instead of my 98mm pistons.it does start w/in 5-10 secs.but initially drags until momentum allows engine rotation.I think I need a fancy battery.Mr. Spectrum,I'll be in touch.
Rick at CD makes a good cable setup.
While the BCM guys really do know their stuff, every bike is going to require a different map- without exception. Slight differences in cam timing (as an example) can have a huge effect on the start sequence.
The are of the map to be focused on here would be start strategy, where you would alter timing and/or spark to get the bike to fire quickly.
Honestly, if your bike doesnt start within 1-2 seconds I would consider remapping. I have always gone through this with my Ducati's- from my 851 to my M1100.
 

·
Premium Member
Joined
·
331 Posts
In 2001, all the superbikes were fitted with a revised starter motor gear ratio that draws less current and made it possible to start the bike using a smaller OEM battery. That’s when Ducati started using the smaller gel battery on their bikes.

The starter gearing on the MY 2000 and earlier bikes like yours is not well suited to the smaller batteries. They starter motors draw too much current during starts.

The limiting factor for using smaller batteries is that they have limited reserve capacity for prolonged or repeated start tries. Their lighter weight certainly has a place on track bike but may not be reliable in colder climates or when used on high compression engines on the street. I understand that the new Panigale has a compression release to reduce current draw when using a smaller OEM gel battery.
Good point about the starter reduction gear. Is that something that can be swapped between Desmoquattro engines without splitting cases?

Opinion: Shazzam is as usual, correct. A lightweight battery is not always the correct battery to use. We often point people towards Odyssey or Yuasa when their use case demands it.
However- We often find the limiting factor to using a lightweight battery on these bikes is not the battery, but is choosing the correct battery for the application, as well as understanding how to care for a lightweight battery.

As a general rule, people want to use the smallest battery that can start their model of bike- in perfect running condition under perfect circumstances. In other words, a battery that is only "just" adequate. Remember when people were trying to start 999's with a YTZ-7s?
When you then factor in the big bore kit, cams, and so on, the battery is no longer adequate.

When an OEM specs the battery for their production bikes, they have to account for a worst case scenario, so they install a battery with much more capacity than would be needed in a perfect world.
A lead battery will also "slow down" as you crank it- so you can "hear" that it is going flat...and you stop. (It is actually a function of the lead heating and creating resistance) With lithium, this doesnt happen, so you hold down the start button until there is nothing left.

To solve this challenge, our batteries have an interrupt circuit which stops current flow during such attempts, and then resets after it is safe. Again, if your bike requires 10 seconds of starter- the problem is not the battery...
 

·
Registered
Joined
·
87 Posts
Happened to me a few months ago on the hwy. Left me stranded for 3 hrs till I figured it out. Got it to work after sitting on the hwy for a while and rode home.
 
1 - 12 of 12 Posts
Top