Emergency Battery Q. That will probably get me in trouble.

[Stucker]

I have searched all over and have yet to find an answer. I'm sure it's out there and I risk getting scolded but I'm asking anyway.   Upgrading batteries to 4 6v Trojan T 145's. I plan on keeping my 1-2-both switch factory set for now and will not run alt directly to main bank.  I need to buy a small emergency battery (starting battery).  Because I plan on using the main bank for everything, including starting, should my back up be a small "starting" battery or a small "deep cycle" battery.  The smaller the better as I may try and fit it on the Starboard side of the water heater.   Is group 24 too small if it's just a backup to get the engine running?

Excuse the dirt you see in the picture. The boat is brand new to me and needs a good cleaning.

[Stu Jackson]

>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>
The smaller the better as I may try and fit it on the Starboard side of the water heater.   Is group 24 too small if it's just a backup to get the engine running?

That will be just fine.

[britinusa]

How do you resist the temptation?

I get suckered into every mod I can do 'While I'm in there' 

Paul

[Jon W]

I installed a group 24 650 CCA as a reserve battery on position 2 of the 1-2-B switch. Have only used it a couple times in the beginning as a test but it started the m25xp easily. When time to replace it I will look for higher CCA for more margin.

[Noah]

That is the same size (flooded, sealed, maintenance-free) battery I have as my primary engine "start battery"and it can be combined with my house (4) T-105s in an emergency. It works fine.

[Paulus]

I put in the T 125 Trojan batteries and the T 105 are the same height.  Thought the T 145 were to tall.  Might check the height of these.
Paul

[mark_53]

I have searched all over and have yet to find an answer. I'm sure it's out there and I risk getting scolded but I'm asking anyway.   Upgrading batteries to 4 6v Trojan T 145's. I plan on keeping my 1-2-both switch factory set for now and will not run alt directly to main bank for now.  I need to buy a small emergency battery (starting battery).  Because I plan on using the main bank for everything, including starting, should my back up be a small "starting" battery or a small "deep cycle" battery.  The smaller the better as I may try and fit it on the Starboard side of the water heater.   Is group 24 too small if it's just a backup to get the engine running?

Excuse the dirt you see in the picture. The boat is brand new to me and needs a good cleaning.

Your going to spend the time and money to install a battery you may never use for the peace of mind knowing it's there if you need it.  You can accomplish that to a large extent with a battery jump starter without all the wiring your currently planning.  If you install so the start battery is used for each start, your essentially adding amp hrs to your house bank...but as Stu says' YBYC.   Am I mistaken or is that the battery box in the picture?  What is the water heater doing in there?  Normally, the water heater is under the galley sink.

Also, keep in mind your batteries should be in a sealed acid proof enclosure.  Refer to mainsail's post.
http://c34.org/bbs/index.php/topic,9360.30.html

[Stu Jackson]

What is the water heater doing in there?  Normally, the water heater is under the galley sink.

He has a Mark II.

[Fred Koehlmann]

Scott,
We had a MkII as well (#1602). We took out our 2 massive 4D battereis and replaced them with 4 - 6volt. I had to build a custom tray for them to sit in, and then we built a small shelf on the outboard side of the hot water tank to hold a Canadian Tire Marine battery as a spare. I think it was a 31 (don't quote me thou). I then upgraded our charger. Got rid of the Flyback charger and installed a ProMariner ProNautic 12-40P charger. Still wanted to fix the alternator wiring, but still haven't go to it. I've been meaning to post picture of it, but haven't had time to do the write up that I had planned to do, but here are some of the pics...

First the battery tray shots.

[Fred Koehlmann]

Once the tray was in place, I lined the bottom with rubber and the edges with flexible wire casing. Because the form was built up from cardboard replicas of the battery foot print, they fit in nice and snug, without any wiggle room.

Four (4) D-bolts, two in the floor plate and two in the galley bulkhead acted as anchor points for tie down straps.

[Fred Koehlmann]

The existing charger we removed, as well as its mounting plate and trash bin shelf. Cut an opening and installed a four sided box in behind the opening. The box was open to the bottom to allow the wire to go down and under the galley bulkhead into the battery locker.

You can just see the spare battery beyond. I though i took more picture of it, just still need to find them. And that's the old Flyback charger over there by the trash bin.

[Fred Koehlmann]

...and the box for the charger, also acts as the new shelf for the trash bin.

[Jon W]

Really nice work Fred.

[J_Sail]

I second Jon's comment regarding Fred's work. I don't see, though, an answer posted to the original Q of whether a starting battery is preferred over a deep cycle type.  That answer is that a starting type is definitely the right one for your application. It will give you more starting omph for a given size.

Jeremy

Note: Starting-type batteries are optimized for max short-term cranking amps (using a higher number of thinner plates to maximize surface area). Deep discharge batteries have a smaller number of thicker plates and handle repeated deep discharge better. 

[Stucker]

Once the tray was in place, I lined the bottom with rubber and the edges with flexible wire casing. Because the form was built up from cardboard replicas of the battery foot print, they fit in nice and snug, without any wiggle room.

Four (4) D-bolts, two in the floor plate and two in the galley bulkhead acted as anchor points for tie down straps.

Wow!  You're hired. How much to get you to 1000 Islands to do the exact sme thing for me
You could sell those trays;).  Thank you for posting all of those great pictures.  I would love to see the shelf you built for the fifth outer battery. I'm not the handiest of wood workers so I love copying other peoples good ideas. 

A couple of questions.  Why did you remove the wood divider between the main bank and water heater?  Also, why did you feel the need to upgrade chargers? 

Like you, I'm in Toronto and my boat is 2.5 hours away so it gets tough to get these projects done.

Thanks for your advice.
Scott