Cranking Amps Required For 12V71

[scottinsydney]

Curious: What is the cranking amps (or watts) required for a 12V71 32 volt starter motor please?

At the moment we have 4 x 180ah deep cycle golf cart batteries in series to start each motor. But they do not give CCA.

[bigbill]

they dont give cca because they are not cranking batteries. if i remember right cca is for below 32 degrees (cold cranking amps)

[Briankinley2004]

I have no issues turning over my 12V71's with 4 GC8's but I am in Florida. I usually use the parallel switch to make it a double bank but it does fine without it. I agree they are not cranking batteries but again we use cranking batteries for house batteries with the 8D's if you have the standard Hatteras set up where port battery bank is house and start

[madhatter1]

Brian, the parallel switch is a great idea but occasionally (guessing you probably already do this) start just on the individual bank. This way you test the heath of each bank. I did this all the time on my 34 and suddenly had a big issue when one was completely dead. The parallel switch masked the problem. We got lucky, both started, and we were close to home.

[scottinsydney]

I subsequently found an old 2006 HOF post saying that CCA at 32 volts for a 12V71 starter motor is about 950 amps. (1900CCA for 12 volts.)

[Canuck Dennis]

Agreed that is what I was told by my dd dealer, at 32v I believe it was 1200 minimum.

[edward]

The auto rule of thumb was one cca per cu, inch, more is better .

[Briankinley2004]

Brian, the parallel switch is a great idea but occasionally (guessing you probably already do this) start just on the individual bank. This way you test the heath of each bank. I did this all the time on my 34 and suddenly had a big issue when one was completely dead. The parallel switch masked the problem. We got lucky, both started, and we were close to home.

Great point and that is what I do. In fact my starboard, non golf cart, bank just took a dump and that is how I figured it out. Currently cranking with the parallel switch until I can get someone to help me haul those old 8V21's out. That is another issue I won't have with the GC8's.

[madhatter1]

My sons are 21 and 23, I’m covered for hauling batteries 😁, unless I’m on a trip. Then I’ll find some Yutes and make it well worth there while to help me out.

[scottinsydney]

I have just been quoted US$3000 for a single PORT SIDE custom made lithium starting battery. 60amps at 32 volts with 1000CCA discharge for 18 seconds. 50lbs weight. Charges without using a BMS from the 32 volt alternator. -20 to 80 degrees C operational range. Made here in Sydney.


Apart from the cost, the issue is that 60 usable amps is actually less than the 90 usable amps from four golf cart batteries. The only 32 volt house circuits that remain attached to the Port battery bank are the bilge pumps, autopilot and radar.


These are the same batteries that are now used as starting batteries on Sydney Harbour ferries. Manufacturer also supplies the military. Technology is on the move. I would love to be done with the golf cart batteries.

Curious as to HOFer's views. I freely admit to investigating and liking new technology.