Battery Question

[derch]

Hey All. A round for the house on me!!
I have a question relating to battery cranking amps. I am in the
process of building a bike. I will be running a 113" Ultima motor. I
read an article on BikerNet about Big Boar batteries. They make a
mini battery that produces 200 cranking amps. The nice thing about
this battery is that it is only 51/4" tall instead of the 61/4" of a
standard Harley battery. Space has become an issue and I can use the
extra inch of this smaller unit. However, in the article they mention
that they recommend the next larger battery on bikes with motors over
100". The untima motor has compression releases installed and I do
plan to always use a battery tender charger to keep the battery fully
charged. I am also using 1.4kw starter. The Ultima documentation
recommends 200 cranking amps for their 100" motors and 350 amps for
their 120" and larger engines. They don't recommend anything for the
113" engines. I would really like to be able to use the smaller
battery and was wondering if anyone can make any suggesions. Thanks
in advance!! Rich.

[Broderick Crawford]

Build a battery box that will fit a small car battery. They you won't
have to fart around with batteries every year.

[Albrecht via MotorcycleKB.com]

derch wrote:
>Hey All. A round for the house on me!!
>I have a question relating to battery cranking amps. I am in the
>process of building a bike. I will be running a 113" Ultima motor. I
>read an article on BikerNet about Big Boar batteries. They make a
>mini battery that produces 200 cranking amps. The nice thing about
>this battery is that it is only 51/4" tall instead of the 61/4" of a
>standard Harley battery.

What is the cold cranking capacity of the Harley battery you're thinking
about using?

Capacity is related to the surface area of the plates, but it's hard to tell
how many plates and what the area is by reading online catalogs, but you
might be able to figure out what size battery you have room for, and work
from the dimensions of whatever battery has the power you're going to need.

> Space has become an issue and I can use the
>extra inch of this smaller unit.

Maybe you have room for a longer, or thicker battery that has more cranking
amps?

> I am also using 1.4kw starter.

That's almost two horsepower. But a big twin needs a strong starter, because
it's cranking against the compression of one cylinder that's about to fire
and the other cylinder is coming up to fire 45 degrees after the first one.

>The Ultima documentation
>recommends 200 cranking amps for their 100" motors and 350 amps for
>their 120" and larger engines. They don't recommend anything for the
>113" engines.

The Honda VTX-1800 is about 110 cubic inches.

http://www.motorcyclebatteriesusa.com/battery-mfg-details.asp?battery=167

Model : Yuasa YTX20HL-BS Battery

*12 volt 18 amp hour
*Powerful 310 cold cranking amps
*6 7/8"L x 3 7/16"W x 6 1/8"H

Study the online catalog.
http://www.motorcyclebatteriesusa.com/battery-mfg-makes.asp?battery=8

--
Message posted via MotorcycleKB.com
http://www.motorcyclekb.com/Uwe/Forums.aspx/tech/200706/1

[MadD...@yahoo.com]

A 1.4 KW. starter will draw a bit under 120 Amp.s at 12V., more if
there's drop.
(There's always drop, probably to about 10V. which make it 140 Amp.s)
The numbers match, but don't expect that battery to last too long.
MadDog