Question on portable jump starter

[skipmac]

Originally Posted by Dougtiff

The engine start and house bank should be charged thru the START battery, not the house bank, via a combiner and have a 1-2 switch as a back up [nigel calder]

Not sure where you get this information. My copy of Boatowner's Mechanical and Electrical Manual, third edition on page 37, "With a dedicated cranking battery and a single house bank, the wiring will be as in Figure 1-33B." Figure 1-33B clearly shows the alternator wired directly to the house bank, not the starter battery.

Other diagrams in the same chapter showing alternate setups using paralleling relays for example, also show the alternator wired directly to the house banks.

[jeepbluetj]

Originally Posted by MarkusK

I have no experience with a portable jump starter nor do I want/need the hassle of extra gear.

Wouldn't it be easier to follow an established routine: i.e. once engine has started, then put selector switch back to 'off', then untie lines?

'cause if you put it to 'off' with the engine running you likely just fried your alternator.

For most folks, charge the house with the alt. Use a batt combiner to charge a much smaller start batt. Start only from the start batt. Simple, almost foolproof, and cheap. Don't mess with the 1-2-all-off switch at all.

[skipmac]

Originally Posted by jeepbluetj

'cause if you put it to 'off' with the engine running you likely just fried your alternator.

For most folks, charge the house with the alt. Use a batt combiner to charge a much smaller start batt. Start only from the start batt. Simple, almost foolproof, and cheap. Don't mess with the 1-2-all-off switch at all.

This method is simple, easy, foolproof and inexpensive. I just don't understand why so many are so resistant to doing it this way.

[Larry Florida]

Bought one at Walmart. Used it to sail an entire season while sorting out the electrical. Without it was dead in the water. Took her home every day for a recharge. Brilliant

[MarkusK]

Originally Posted by jeepbluetj

'cause if you put it to 'off' with the engine running you likely just fried your alternator.

I didn't believe this but you are correct...this bakes the diodes. Lesson learned. So glad I joined CF.

[mowerandy]

Originally Posted by CHRIS V CLEMENT

I have a Stanley Power Station, Part No. STA-PPRH7DS.
Cost is approx $100.
It has 1400 peak amp output.
It cranks my V8 cars and Marine Perkins 4-108 with no issues at all.
It also has a built in inverter, so bringing 115v sound systems to any secluded beach to play Jimmy Buffet tunes all day is not an issue.
It also has a built in compressor for inflatable animals, car or trailer tires.
I bring it with me almost everywhere, but not in to Church.
It is amazing how many stranded road warriors, and sailors have been sent on their way with this one device.

I also have a jump pack (on my third now, over the years) - very handy. I usually get the crappy type from auto discounter stores. The thing to be aware of is that the cheaper ones ratings don't mean a darn thing. Mine is rated at 1900amps, but it cannot deliver more than about 300 to the terminal clamps, and this is very common I understand. Learned this by not being able to crank my diesel 4 cylinder car with it (which needs around 400CCA) after disconnecting the main battery, or if completely dead. The only way is by letting the jump pack recharge the main battery for a few minutes before attempting to crank the motor. Maybe the internal battery in the pack can indeed deliver 1900 at its own terminals (or maybe not), but not at the clamps, so the labelling can be very misleading. Still pretty handy tho, and has saved the day on numerous occasions for numerous folk.

[DeepFrz]

Originally Posted by Dougtiff

The engine start and house bank should be charged thru the START battery, not the house bank, via a combiner and have a 1-2 switch as a back up [nigel calder]

NIET comrade. See skipmac's post #16.

[Rocinante33]

Thanks for all of the suggestions, I guess for me it makes sense to put the house bank on one, the starter on the other and just make it part of the routine to always switch to 'one' as part of the nightly routine and back to 'both' as part of the morning.

I have been thinking about laminating a little card with morning/starting on one side and evening/leaving on the other, similar to what pilots used to (or maybe still do?) as part of their pre take off routine.

Guess the glove box starter (in my case) is one more thing to fail, and a starter battery will be less than $75.00 and more likely to be there in a crunch

Thanks again for the ideas and experience!

[guyrj33]

About the use of the 1 2 both switch, I have an asymmetric battery bank. My starting battery is 90ah and my house bank is 225ah.
I start with the switch in position 1 let the engine run for a few minutes and then switch to 2, the house bank.
it only takes a fraction of an amp hour to start your engine, yes that's right 500amps x 15 seconds of cranking is only a fraction of an amp hour.
your starting battery won't need much time to recharge and you'll want to put as much charge into your house bank as you can.
I do like the suggestion of wiring your alternator to your house bank and using a combiner to charge your starting battery. But I don't have a combiner so I just use the 1 2 Both switch to keep everything charged.
I have flooded lead acid batteries (golf cart) and a 70-90 amp Balmar alternator, I mention this because it's beneficial to have an alternator that can supply the maximum charge current that your batteries can accept