Cranking Battery

[Re and Frank Puff #691]

How many cranking amps is sufficient for the XP 25?  We have a seperate battery under the aft bunk for this purpose and another bank, 4 Trojan 6 volts batteries, for "house".

Since the house bank is wet cell, I assume that one cannot use gel cell.  I am also assuming one can use the totally sealed "maintenance free" batteries?

[tassber]

I added a 1000amp absorbed glass mat starting battery for my 4cylinder universal engine.  The battery is physically small, needs no maintance, and can be mounted in any position.  It works great.

mike

[cholder]

I don't know exactly the current draw for a 25XP but the glow plugs are about 30A.  The starter moter current will probably depend on how hot the starter is at the time.  

I've installed an anchor windlass connected to one battery bank.  I know that draws up to 100A because the circuit breaker will pop occasionally.

However, I can assure you that I've used two banks of Trojan 6 V batteries for at least five years and haven't had any concerns about starting the 25 XP on my C34, nor about the longevity of the batteries.

I do suggest you use heavy cabling, i.e. replace the #4 cables with at least 2/0 better still 3/0.

[Tim W]

For what it's worth.....

the single best thing you can do is add parallel #4 battery cables throughout the boat. This will effectively give you 1/0 gage wiring which is what Catalina should have used to begin with. It's one of the best improvements I've ever made.

Tim W
1988 # 679 Tropic Desire

[rdavison]

I'm not sure of the reason for your question as you already have a starting battery under the aft cabin?

I just installed a U1 (small!) Trojan AGM on its side under the aft cabin.  This in addition to the same 4 X 6 house bank you have.  I wired the starter battery directly to the solonoid and engine ground with 2/0.  My 35A now cranks much faster than it used to off the house bank thru the old #4 wiring.

We measured the cranking amps at room temperature at Pacific Power while I was deciding on the size of starter battery I wanted.  The Trojan AGM put out 380 Amps for the 30 seconds or so we ran the test so I went with it.

Just for insurance, I wired in a switch to allow the house batteries to feed the starter circuit if needed.

Randy Davison  #1268 1993 k7voe