I just bought one of those portable jump start units for the boat (sealed lead acid battery, 18 amp/hr). My intention is to use it as a back-up for the primary battery for starting and maybe for music. I will use oil lamps for most other lighting. It comes with a cord to recharge it off a 12 volt system. My question is (I'm not too electrically smart) what are the consequenses of charging it off my system (one battery, group 27 starting), presently used for starting the outboard and using the running lights, charging off a 9.9 Suzuki. Will it charge before the starting battery? Will it charge after the starting battery? Will they charge at the same time innefficiently? Will one of them blow up? Should I just charge it at the dock after using it? Can I write without using parenthesis and commas? I know that I should complete my rewire of my boat with a second house bank, but I am trying to get it together to take a short ICW trip in Oct.(mostly motoring) and don't see that happening before then what with having to waste time with work and home responsibilities. Any thoughts?
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Pops, I don't know about your wiring but
your writing is great!
Well, I can respond to your wiring concerns a little too. I would think that a group 27 battery will do everything you need it to do on your boat, assuming it's not too old. I would keep the emergency power in reserve. Don't use it for anything except,,,you know what.
your writing is great!
Well, I can respond to your wiring concerns a little too. I would think that a group 27 battery will do everything you need it to do on your boat, assuming it's not too old. I would keep the emergency power in reserve. Don't use it for anything except,,,you know what.Handy little item
Mine can be used as an air compressor and it has a light (not that a I use it for light). But I know it is good for at least 3 jump starts before needing a re-charge because I've used it to get cars in the parking lot going. I keep it on the boat for re-assurance and bring it home occasionally to make sure it's charged off 120 V recharger.
Mine can be used as an air compressor and it has a light (not that a I use it for light). But I know it is good for at least 3 jump starts before needing a re-charge because I've used it to get cars in the parking lot going. I keep it on the boat for re-assurance and bring it home occasionally to make sure it's charged off 120 V recharger.
No Problem
Ahoy Pops, There should be no problem charging both from the outboard. Your lil Suzie should have a pull cord under the engine cover in the event of a catostrophic failure. One thing to keep in mind, The weakest link in the chain is the lowest charged battery. If one battery is at say 11 volts and the other is at 12.5 the 11 volt battery will drain the 12.5 battery until they are of equal voltage. If your alternator is charging then it will bring both batteries up with no harm. Fair Winds Cap'n Dave
Ahoy Pops, There should be no problem charging both from the outboard. Your lil Suzie should have a pull cord under the engine cover in the event of a catostrophic failure. One thing to keep in mind, The weakest link in the chain is the lowest charged battery. If one battery is at say 11 volts and the other is at 12.5 the 11 volt battery will drain the 12.5 battery until they are of equal voltage. If your alternator is charging then it will bring both batteries up with no harm. Fair Winds Cap'n Dave
You can Charge While Motoring
With an o/b charger, you can charge while motoring. Actually I was told by the mechanic that they can overcharge, so to run a cabin light to burn off the excess. They will charge together, but if you charge it at home, it will be more convenient (and trustworthy).
With an o/b charger, you can charge while motoring. Actually I was told by the mechanic that they can overcharge, so to run a cabin light to burn off the excess. They will charge together, but if you charge it at home, it will be more convenient (and trustworthy).
Emergency Charger
Having an emergency charger around was one of my better purchases this summer. Keeping it fully charged is a necessary evil. One more maintenance headache, but when needed, it saves the day. The unit can be charged by 120V and left plugged in. The unit can be charged by 12V (with the engine running) but should only be plugged in for 4 hours (or so; from memory). It doesn't drain, per se, from your Group 27 because the engine provides more than enough current. But the higher voltage will charge your unit quickly and doesn't need more than a few hours to fully charge. Your jump start system won't 'charge' the main battery; it is just a jump start system after all; it can be used for music, light, etc. If I had one main battery, I'd keep the jump start strictly as backup, fully charged and otherwise not used. My logic is that I'd run the main battery down as necessary and restart the engine as needed to recharge the main. I would run music and lights off the main battery. If I do mess up and lose too much juice, the jump start system is there to ensure that I can get the engine running. The jump start system is a good secondary battery with many uses. Rebuttals? I know you're out there....
Having an emergency charger around was one of my better purchases this summer. Keeping it fully charged is a necessary evil. One more maintenance headache, but when needed, it saves the day. The unit can be charged by 120V and left plugged in. The unit can be charged by 12V (with the engine running) but should only be plugged in for 4 hours (or so; from memory). It doesn't drain, per se, from your Group 27 because the engine provides more than enough current. But the higher voltage will charge your unit quickly and doesn't need more than a few hours to fully charge. Your jump start system won't 'charge' the main battery; it is just a jump start system after all; it can be used for music, light, etc. If I had one main battery, I'd keep the jump start strictly as backup, fully charged and otherwise not used. My logic is that I'd run the main battery down as necessary and restart the engine as needed to recharge the main. I would run music and lights off the main battery. If I do mess up and lose too much juice, the jump start system is there to ensure that I can get the engine running. The jump start system is a good secondary battery with many uses. Rebuttals? I know you're out there....
K.I.S.S.
Capn' Dave has all the right answers. Might I suggest you employ the "keep it simple" philosophy & check to see if you have a pull start option on the motor (per Dave). Best to give it a try at the dock to ensure it works properly. That is all the backup you really need. Leave the portable charger at home for your auto (which doesn't pull start nearly as easily). A single group 27 battery will do the job just fine! Happy sailing!
Capn' Dave has all the right answers. Might I suggest you employ the "keep it simple" philosophy & check to see if you have a pull start option on the motor (per Dave). Best to give it a try at the dock to ensure it works properly. That is all the backup you really need. Leave the portable charger at home for your auto (which doesn't pull start nearly as easily). A single group 27 battery will do the job just fine! Happy sailing!
Right on
Lots of good info on this post. Like all of you, I keep the "jump start" on board my Catalina 30. Even with two group 27 marine batteries and an inboard diesel, it feels good to know that package is on board. The price is right and it can save the day when unforeseen problems arise and "murphys law" is at work. I charge mine with shore power on occasion. additionaly, the Admiral is happier knowing it is available. keep it as a backup and good sailing to you. John
Lots of good info on this post. Like all of you, I keep the "jump start" on board my Catalina 30. Even with two group 27 marine batteries and an inboard diesel, it feels good to know that package is on board. The price is right and it can save the day when unforeseen problems arise and "murphys law" is at work. I charge mine with shore power on occasion. additionaly, the Admiral is happier knowing it is available. keep it as a backup and good sailing to you. John
Why not
just improve your "real boat" battery and electrical system and stop depending on jump starts from additional (and questionable) equipment to begin with? Having another piece of equipment on board that requires dragging down to the boat, recharging, and securing, makes very little sense to me, but it sure seems like a lotta people like having Mr. Tow truck right on board. Why not simply get another battery for the boat, leave it there, charge them all properly and you never have to schlep the jumper again. Plus, ya gotta charge it like a real boat battery anyway. I just don't get it... Sorry, Stu
just improve your "real boat" battery and electrical system and stop depending on jump starts from additional (and questionable) equipment to begin with? Having another piece of equipment on board that requires dragging down to the boat, recharging, and securing, makes very little sense to me, but it sure seems like a lotta people like having Mr. Tow truck right on board. Why not simply get another battery for the boat, leave it there, charge them all properly and you never have to schlep the jumper again. Plus, ya gotta charge it like a real boat battery anyway. I just don't get it... Sorry, Stu
I'm with you, John and PHitchcox
My Commodore rests easier knowing the jump starter is resting under the dinette, and so do I. And even though I know I'll hear from Stu, I'll confess that in addition to 2 Group 27s, I also have a Group 8D that a PO installed under the dinette, so I qualify as being REALLY paranoid ;D Remember, just because you're paranoid doesn't mean Mr. Murphy isn't out to get you *666 BTW, before anybody lectures me about the details of lead-acid batteries, I KNOW batteries, especially large banks. I had the pleasure of installing, filling, charging, selling and maintaining dozens of banks of 48v and 260v Exide batteries in Egypt some years back. The stories I could tell *yks Cheers, Bob s/v X SAIL R 8
My Commodore rests easier knowing the jump starter is resting under the dinette, and so do I. And even though I know I'll hear from Stu, I'll confess that in addition to 2 Group 27s, I also have a Group 8D that a PO installed under the dinette, so I qualify as being REALLY paranoid ;D Remember, just because you're paranoid doesn't mean Mr. Murphy isn't out to get you *666 BTW, before anybody lectures me about the details of lead-acid batteries, I KNOW batteries, especially large banks. I had the pleasure of installing, filling, charging, selling and maintaining dozens of banks of 48v and 260v Exide batteries in Egypt some years back. The stories I could tell *yks Cheers, Bob s/v X SAIL R 8
($.02)
Ahoy Pops: double check that brand new portable jump start unit box for the MFG instructions, they will most likely give you the best info for you to charge it. Remember to disconnect your (near)dead shorted out batts before connecting your FULLY charged EMERGENCY jump start unit to start your O/B or turn on the save me radio. there is some good batt info in Archive. Remember some mechanics are missunderstood and then misquoted and then, some are just maniac.
Ahoy Pops: double check that brand new portable jump start unit box for the MFG instructions, they will most likely give you the best info for you to charge it. Remember to disconnect your (near)dead shorted out batts before connecting your FULLY charged EMERGENCY jump start unit to start your O/B or turn on the save me radio. there is some good batt info in Archive. Remember some mechanics are missunderstood and then misquoted and then, some are just maniac.
ebay
I got one for the wifes car, one for my son and one for the boat on ebay. They work fine and I didn't pay over $35 (including shipping)for any of them. They also have compressors built in which I will use to blow out my fresh water lines when I winterize. Pretty cheap insurance
I got one for the wifes car, one for my son and one for the boat on ebay. They work fine and I didn't pay over $35 (including shipping)for any of them. They also have compressors built in which I will use to blow out my fresh water lines when I winterize. Pretty cheap insurance
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