Spare Battery or JumpPack?

[HenryD]

Six plus years ago when we moved aboard, I had a spare series 27 battery from the prior boat. I put the spare battery in the lazerette and it has come in handy a few times as a 12v source for running a drill pump, as a battery I could lend to a broken down boater, and peace of mind to know I could always jumpstart any of my motors.

The battery will no longer take a charge and I am trying to decide - do I go trade this core in on another battery to have around or do I go buy one of these all-in-one Jump packs. I would still keep my 20' jumper cables aboard and my 120v powered battery charger.

Would the Jump packs have enough amps to turn the diesels?

When I look at the jump packs that claim to be able to start a diesel engine, I could buy three spare batteries?

 

[FlyWright]

I keep a jumpstart battery pack onboard as a portable 12V source and for troubleshooting. I doubt mine would start a diesel, but I have lots of other batteries for that purpose. Keeping a set of long quality jumper cables onboard seems to make a lot of sense...something I don't have. (cables.....not sense.)

 

[BruceK]

Those I`ve seen advertised do not have enough CCA, if they did I might buy one.

 

[Billylll]

I used a spare 31 series AGM on my old Mainship. I mounted the battery under the bridges wetbar. It got charged through a BluSea ACR. It came in handy for acting as a large capacitor for the helm's electronics. I could pull it out and lend it as needed. Having a spare set of 20' jumpers and it could have been used to help start a dead or weak engine starting battery. I never had that happen so much for planning...
Bill

 

[Bay Pelican]

While I have a jump pack at home I have chosen a separate 12 volt battery to use on board as an isolated battery just to power a VHF at the helm. I specifically bought this battery because it has a handle for carrying. Over the years I have used it a couple of times to bail out other boaters using jumper cables.

The balance of my batteries are in one large bank in the engine room and if we were ever taking on water they would be shorted out fairly quickly.

 

[Billylll]

While I have a jump pack at home I have chosen a separate 12 volt battery to use on board as an isolated battery just to power a VHF at the helm. I specifically bought this battery because it has a handle for carrying. Over the years I have used it a couple of times to bail out other boaters using jumper cables.

The balance of my batteries are in one large bank in the engine room and if we were ever taking on water they would be shorted out fairly quickly.

My AGM also has a carrying handle for the same reasons you stated. That's the same use for my topside battery to filter the MFD's and VHF radios. I could also power the electronics if I was ever sinking. That boats sold now I'm not sure I'm going to do the same on my new to me Gulfstar although I might at a later date. Jump packs really don't have enough power to crank diesels they will crank gas engines but not for a long period of time.
I have also found most of the jump packs I have had over the years go bad quicker than a stand alone dual use battery.
Bill

 

[jleonard]

I just keep a set of heavy 25 ft jumper cables. I have 2 large battery banks, and a seperate gen battery, I figure I can get enough juice somehow.
My son has an auto repair business and he has several battery jump packs. They won't reliable start every diesel.