my new second battery

[victos]

G<DAYi have a 70 hp evinrude as my main powerplant on my fishing boat /boom box, and have decided to dedicate my main battery to start & tilt the engine and power the cigerette ligther[when the ignition is on only].
my secondary battery that i will use to power all the auxileries this summer from the navigation lights to the 12' amplifier powered subwoofer are conected to my automotive h/d jumper starter pack,the jumper pack comes with a 12volt cigerette lighter adaptor to plug in for charging[while the engine is running]as wellas a wall plug when at home,

i will keep you all posted in the comeing months with current draining scientific experiments


cheers vic

 

[tashasdaddy]

Re: my new second battery

nothing should be attached to the ignition system other than the motor. the cig lighter should have separate fused power source and be on a switch. it should not be attached to the ignition switch.

 

[mphy98]

Re: my new second battery

it appears to me that you are isolating the battery from the motor, that is a good thing because you should always have a good start battery PLUS if that fails you can always change out battery's at sea to start up. good decision. i always have a backup battery onboard just for that occasion.

 

[PondTunes]

Re: my new second battery

What year is that rude? If you're planning on using the outboard to keep both batteries charged you may be disappointed when you go to all the trouble to get everything wired properly.. The first thing you need to do is look up what output your charging system has, remember this isn't a car alternator you're talking about lots of the older model outboards had 10-20 amp charging systems that means as a general rule it will put whatever it is rated at back into the battery in one hour at WOT.. Cranking your engine and letting it idle or putting around the lake won't put much if any charge back on either battery. Many times the charging systems on outboards don't produce any juice at idle.

Before you go out and buy a deep cycle battery take note of the reserve capacity, most are rated at X minutes @ X amps so a 160 minute reserve @ 25 amps means if you had a 25 amp load it would take 160 minutes (2.5 hrs) to bring the battery down below 10.5 volts.. These ratings do vary so be sure to examine them before selecting one..

On the charging side of this your outboard is capable of putting probably 15-20 amps back into that battery per hour where as in your vehicle it's more like 100-150 amps per hour..

The lower amperage from your outboard will take MUCH longer to replenish the charge on your battery, add trying to put charge back into your starting battery as well and you're looking at a very long ride at WOT to put any charge back into the batteries..

What I normally suggest for people with outboards that want a backup battery is to get an on-board charger, a two bank would maintain your starting battery as well. When you get home after a day on the lake plug the charger up and let it re-charge the deep cycle. That way you'll have fresh batteries whenever you plan on going to the lake. You can always add a 2nd deep cycle wired in parallel with the stereo/accessory battery for even more reserve time.

 

[Wee Hooker]

Re: my new second battery

Ditto PondTunes response. Your altinator is not going to keep up with the drain that your talking about putting on the system. in addition, (without knowing the specs of your subwoofer amp and starter pack" I'm guessing that the starter pack is going to get sucked dry fast due to lack of reserve and that power hungery sub. ( Those are usaully designed to start vs sustain a long drawn 12-30 amp drain.) Watch teh 12V cig lighter outlets too. Many will be fused/desgned to handle less than 10 amps.
I'd be thinking a BIG deep cycle battery in that circuit if your going to run that sub.