"William Andersen" wrote in message
...
My Perko switch also has the field disconnect, but it doesn't protect my
alternator. The protection is only afforded to some alternators. I'm away
from home now and don't have the specifics, but the alternator on my 3
liter
MerCruiser isn't protected by the Perko. As soon as I figure out which of
the wires on my alternator to use, I'll connect the Zap Stop.
I did label the Perko switch to remind me to turn off the ignition before
switching. I only use the switch to disconnect everything while the boat
is
trailered, and to rotate which battery gets used for starting duty on a
given day. Both batteries are the same, and neither is wired as a house
battery on my runabout.


Here is what I purchased and will be installing:

http://us.binnacle.com/product_info....oducts_id=1375

According to the manufacturer:

"Has field disconnect- prevents damage to alternator if switch is
accidentally switched to the "off" position while the engine is running."

Why is yours not protected William.....because you did not connect the
switch to the alternator?

No, my alternator isn't protected due to the design of (I think) the
alternator and regulator being one assembly. I don't have any of the
literature with me (on vacation w/o boat). But, it's a limitation of my
alternator, not the Perko switch.

" JimH" jimhUNDERSCOREosudad@yahooDOTcom wrote in message
. ..


"William Andersen" wrote in message
...
My Perko switch also has the field disconnect, but it doesn't protect my
alternator. The protection is only afforded to some alternators. I'm
away
from home now and don't have the specifics, but the alternator on my 3
liter
MerCruiser isn't protected by the Perko. As soon as I figure out which
of
the wires on my alternator to use, I'll connect the Zap Stop.
I did label the Perko switch to remind me to turn off the ignition
before
switching. I only use the switch to disconnect everything while the boat
is
trailered, and to rotate which battery gets used for starting duty on a
given day. Both batteries are the same, and neither is wired as a house
battery on my runabout.


Here is what I purchased and will be installing:

http://us.binnacle.com/product_info....oducts_id=1375

According to the manufacturer:

"Has field disconnect- prevents damage to alternator if switch is
accidentally switched to the "off" position while the engine is running."

Why is yours not protected William.....because you did not connect the
switch to the alternator?

wrote in message
ups.com...

JimH wrote:
I am installing a 2nd battery on my boat with the new group 27 deep cycle
being on the aft starboard side, the exiting group 24 starting battery on
the aft port side. I will be installing an A/B switch near the existing
starter battery.

I need custom cut lengths of #4 gauge black and red battery cable
w/connectors or precut 10 and 4 foot cables with connectors.

Can anyone direct me to a good source with good prices for this?

TIA!


You will need #1 AWG wire to carry a 12-volt, 250-amp load 10 feet
without undue loss.

Golden website for calculating cable sizes:
http://www.ancorproducts.com/

Go to "technical information" and enter the length of your run, the
load (figured 250 amps for typical starting motor), and the voltage.
The screen will instantly calculate your cable requirement. Using the
variables shown above, the computer calculated #1 AWG, not #4.

Certainly don't pay for "custom" cables. Buy the wire you need, cut to
the lengths you want.
So far, you're paying only for the wire as it has to be cut to sell,
anyway. Fittings on something that heavy will need to be swaged or
"pressed" on, and you can just about buy a workable swaging tool for
what some people would charge you to make a handful of connections.


I was able to reduce the length of the run on the #2 battery positive cable
to 8 feet and found a great source for custom cut 2 AWG Marine tinned red
battery cable with only a minor charge for the connectors (and them
installing and heat shrinking them). The price was only a bit more than
what NAPA would charge for a custom cut piece of comparable cable, and this
is marine tinned.

For the ground/negative run I will purchase 10 feet 2/0 AWG black battery
cable from NAPA (they do not carry #1) and put the connectors on myself (lug
connectors).

Thanks again for your help on this (as well as to others who offered
advice)!