Dedicated starting battery location

[2ndwish]

We are thinking about adding a dedicated starting battery and were considering mounting it on the small generally useless shelf in the aft cabin- the one right over the transmission. We'd put it in a battery box and build a decorative box around it for fuse/buss bars and echo charger etc. The advantages of the location are easy access, location above the waterline and a very short run to the starter. Has anyone else considered or used this location? Also, can anyone recommend a good location on the engine for the starter ground wire? I was thinking about the HX mounting plate bolts, which are easily accessible.

Thanks in advance

[TonyP]

2ndwish
ours is right below that under the bed and just behind the motor with two house batteries under the settee just in front of the water heater
cheers
Tony

[Les Luzar]

I have four batteries on Wind Shadow and Three house under the dinette settee forward of the water heater and one engine start under the forward dinette settee. All are easy to access. For the ground cable a new hole was drilled in the bell housing. It is important that the starting battery ground maintains a good ground connection so wherever you put it, make sure there is good metel to metal contact. So access and the ability to clean this contact easily in the future would be an important consideration for location.

[ken003]

I did what you are thinking of in my MKII.  It has worked very well.  The cabinet with the hinged top was useless so I removed the piano hinge and fastened it all together.  The hinges you see in the back are holding it in place.  I can remove the battery and the entire cabinet in 5 minutes.  Short wire runs to the engine and good engine access.  The switch was the original on/off switch located under the nav table.  I did this 6 years ago, meaning to completely enclose the battery but still haven't got to that.

Ken

[Les Luzar]

Ken,
Your battery installation in the aft cabin looks pretty sweet. You did a nice job. It is also nice that your engine start battery is very close to the engine.

[Ron Hill]

2nd : People have mounted a starting battery in many locations, but that aft cabine shelf is a favorate place. 
I mounted mine just fwd of the starboard water tank, but then I also have it in the anchor windless circuit!  It also gets more weight fwd and on the starboard side.   A thought

[2ndwish]

Goes to prove one more time, there's no such thing as an original idea! Ken- Where did you connect the ground?

[ken003]

I don't have a picture of the ground.  It is attached on the port side in a hole like the one shown below of the starboard side.  Cleaned away the paint and fastened with a bolt and couple large washers.  Continuity was good with my other grounds.  It has stayed clean and tight for 2000 hrs.

Ken

[Ken Juul]

Took these last weekend, forgot to post    The shelf is probably easier to do, but this way uses space that is hard to use.   The ground wire goes to the ground post on the port side of the engine.  Positive goes through the additional battery switch to the starter.

[patrice]

Hi Ken,

Like the place you put your battery.
Place that you don't really use for storage.
Mine is located under the settee by the V berth.  A space that could be better used for storage with easy access.

[mregan]

Ken
What would be the purpose of the second battery switch?  Wouldn't the starting battery be wired into the 1,2,Both switch on the elec. panel?

[2ndwish]

For the dedicated battery, the battery becomes hard-wired to the starter. Even if you run it to the 1-2-B switch for redundancy, it remains connected to the starter even when the switch is directed elsewhere, so an additional switch is needed to separate the starter from the new battery.

[Clay Greene]

That's not how we wired our "starting" battery.  It is run through the #2 post on the main panel switch.  The wire to the starter runs from the common post on the switch.  But we use it as a reserve battery and not a dedicated starting battery.  We leave the switch on 1 and use the house bank to start the engine.  The starting battery is available on #2 if we should run down the house bank. 

If you connect the starting battery directly to the starter and do not go through the panel switch, how are you going to recharge the starting battery?  You'd have to run two wires off of the alternator - one for the starting battery and one for the house bank.  You'd also have to run another wire from the battery charger to the starting battery.  Seems like a lot of additional wiring. 

[Footloose]

Clay

An Echo Charger is added between the two banks.  Most of the current goes to the house bank.  Very little is needed to charge the starting battery if it is only used for engine starting.  If it gets used in an emergency to run the house that changes things.

[Ken Juul]

The second battery switch if KISS.  (keep it simple) It also required running less wire.  Main battery on 1 for the house, start battery on... ready to go:)  If either of the banks fail, the house can start the engine if move to the both position or the the start battery can run the house also by moving the main to the both position.  The start battery is charged by an ACR connected to the house bank.  The alternator charge line is also connected directly to the house bank, not though the battery switch.  I chose to do it this way because I was tired of loosing the electronics when I started the engine.