Battery size

[falconbrother]

I moved from an old Harley Electraglide back onto a Valkyrie.  On the old Harley the battery was about the same size as the one on my car.  The battery on the Valkyrie seems like a little battery considering the valk has radios, spot lights, etc..  Also, I have a heated suit with gloves.  It concerns me..  The battery on my wife's sportster is bigger than the one on the valkyrie. 

[Fazer]

Others will chime in if I am incorrect, but all your battery needs to do is turn the starter enough to start the bike and provide enough of an initial spark to run.  Once it's running, everything runs off the alternator.  I don't know squat about Harley's, but I do know the Valk has a very robust charging system.  I run an maxillary fuse panel that powers lights, sound system, heated gloves, power outlet, DanMarc fuel shut off and Big BF quad horns with no problem.  This is my third riding season coming up and I have no idea how old the battery is that was in when I married the gurl. 

I don't think the physical size of the battery has anything to do with its suitability for the Valk.

[hubcapsc]

Engineers figger that stuff out. Our alternators put out
like 60 amps or something like that. I have quad horns,
heated clothes, moto lights and cobra lights on my
1500 Valkyrie. There might be a problem if you
turn on all the lights, hold down the horn button
and take off down the highway with your jacket on
"high", but I never use all of them continuously
at the same time   Some people used their original
Valkyrie batteries for 10 or more years...

-Mike

[Fazer]

Maxillary????  Should have been "auxiliary."

[Jess from VA]

From Chet's pages.

Born of the notoriously over lighted and accessorized Gold Wing and driven by a gear directly off the crankshaft, the Valkyrie alternator has an output of 546 Watts and 14.2 volts at 3500rpm.

But they don't charge much at idle, so don't sit idling all day.  LOL

But all batteries eventually die, and you can harm/overwork your alternator running on a failing battery.  And you don't want to have to replace/repair your alternator because it is a Rubic's cube getting the bastard in and out.

Properly charged and maintained with good clean connections all around, the OE Yuasas last for years and years.  

My 1986 Hog FXRD needed a battery almost every year (18 years)..... and an upgraded charging system (OE was a lousy 22 amps), and new voltage regulators and stators all the time.  Thus the move to Honda.

[MarkT]

The alternator is about 39 amps.  The engineers sized the battery to the charging system.  That match is what counts.  e.g. I installed a 1.3kW Compufire alternator in Deerslayer.  About 97 amps.  W/O changing the battery.  The alternator cooked and ruined the battery and it's replacement.  Went to the bigger one, GW sized to match the alternator.  No more problem.

[The emperor has no clothes]

The alternator is about 39 amps.  The engineers sized the battery to the charging system.  That match is what counts.  e.g. I installed a 1.3kW Compufire alternator in Deerslayer.  About 97 amps.  W/O changing the battery.  The alternator cooked and ruined the battery and it's replacement.  Went to the bigger one, GW sized to match the alternator.  No more problem.

I didn't know that. I assumed the extra amperage was just "dumped", for lack of a better word. I have an 85amp alternator. I hope it doesn't crap out the battery, those things aren't $25 anymore.

[Harryc]

I didn't know that. I assumed the extra amperage was just "dumped", for lack of a better word. I have an 85amp alternator. I hope it doesn't crap out the battery, those things aren't $25 anymore.

I'm with you meathead. In a 'normal' system the regulator/rectifier would and should dump any excess amps going to the battery. Why doesn't that work in a Valk with a super alternator? Overloaded? Too much heat? R/R not designed for it? I am sure the answer lies in the fact that I don't understand exactly how a Valkyrie alternator works. I'd like to learn about it though ...

[Hook#3287]

I didn't know that. I assumed the extra amperage was just "dumped", for lack of a better word. I have an 85amp alternator. I hope it doesn't crap out the battery, those things aren't $25 anymore.

I'm with you meathead. In a 'normal' system the regulator/rectifier would and should dump any excess amps going to the battery. Why doesn't that work in a Valk with a super alternator? Overloaded? Too much heat? R/R not designed for it? I am sure the answer lies in the fact that I don't understand exactly how a Valkyrie alternator works. I'd like to learn about it though ...

I'm with ya on that Harry, that lectic stuff is vodo magic to me

[WintrSol]

Yes, when the Voltage limit is reached, the regulator should shut the alternator down. I think the bigger alternator can cook the battery because the charge current could be so much higher during the time that the battery recovers the starting current. The SM says fast charge current for the stock battery is only 4A. At the low rpm right after startup, the 39A alternator will provide less current than 39A, when the battery is recharging, with the rest of the system using much of that supply. A higher output alternator will provide more current during this time, possibly pushing too much current into the battery, and eventually damaging it.