can i add an alternator

[rustyh]

i have a 40 hp merc 1982 ser# 6142511 .........i have added serveral accesories such as fish finder, radio, trolling motor, elect winch for anchor, lights for night fishing and docking , plus all the normal stuff like navagation lights bilge pump and areator in live well ..........anyway i have 1 deep cycle batt and 1 starting batt and was wondering if i could add a alternator or some type of charging system to charge up batt while engine is running or should i just add another deep cycle batt in series with the first one or run seperate for certian equip

 

[Laddies]

Re: can i add an alternator

You should have a alternator even the manual start engines had the stator installed with the 2 yellow wires clipped. Check the wire that come from underneath the flywheel if there are 2 yellows connected to a rectifier and it is not charging you need to test the rectifier as the charging part of the stator seldom gives any problem, if there is no rectifier see if you can see the 2 yellow wire stubs taped under the flywheel and if they OHM test OK then all you need is a rectifier and some wire to make it charge. Let us know.

 

[rustyh]

Re: can i add an alternator

i have rectifier and that rturns to the starting battery will this have enough amps to charge a deep cycle as well ...i really did not want to put these two batt in series b/c if all else quits i still can crank motor and go home also how would you trouble shoot a rectifer to see if it is working or not

 

[Laddies]

Re: can i add an alternator

You best anwser is to buy a battery isolater it will chare the start battery and when it's charged automaticly change to the number 2 battery and you can get them to charge as many as 4 battery. When we install we one usually install a switch to switch a voltmeter from one battery to the other, but you don't really need one.

 

[rustyh]

Re: can i add an alternator

kewl thanks for the info

 

[rustyh]

Re: can i add an alternator

what type of isolater will work with my motor spec ( top of page ) most i found need alternator data and unsure what to buy also would like to add 1 more batt for run in series for more pwer and want to make sure fits both applications so in the end would have 2 deep cycle in series and one stand alone starting batt

 

[Laddies]

Re: can i add an alternator

Here's a great link for wiring diagrams and products. Just think of the + on their alternator as the + on your rectifier. http://www.arcomarine.com/xhtml/Pages 60-62 Battery Isolators.pdf

 

[rustyh]

Re: can i add an alternator

last question i promise.......how many amps does this particular ectifier put out the batt isolators i found can have no more than 70 amps and the batt i have are 100a/per hour rated will this work or do i need a 100a or more battery isolator

 

[matt9923]

Re: can i add an alternator

I would do what they said but maybe you can add a charging system that you can plug in when you get home and keeps everything charged. Like big boats do when docked. Just a thought.
Matt

 

[Silvertip]

Re: can i add an alternator

YOur thoughts about charing a deep cycle battery is valid only if you plan to run wide open for hours. The alternator output on that engine is not very large. The alternator was originally designed to keep the starting battery topped off -- not to fully recharge a deeply discharged battery. The suggestion that you install an on-board charger and plug in at the dock is a good one. Also, you do not connect two deep cycles in SERIES. That provides 24 volts. You connect them in parallel which doubles the capacity but keeps the voltage at 12 volts.

 

[matt9923]

Re: can i add an alternator

Also, you do not connect two deep cycles in SERIES. That provides 24 volts. You connect them in parallel which doubles the capacity but keeps the voltage at 12 volts.

Is their a thread that explains how to parallel connect 2 bats that. Iv seen people fry their whole system doing similar things (no fuse system either...)

Matt If your running more then a few simple lights you'd better have a fuse box and 2 deep cycles connected the right way. As well as put in an on board charger to plug in when you get home or dock. Then you don't have to mess with chargers out in the rain and moving things around just plugging it in.
Matt

 

[fyrfightr]

Re: can i add an alternator

To keep 12 volts with 2 batteries, connect positive to positive... and negative to negative. Most people end up frying items by wiring the batteries in series, creating 24 volts.

As for using the the charging system on the outboard to charge the deepcycle battery, I would not try it. You may be able to charge to the deepcycle battery by making long high speed runs, but you will end up burning up your stator.

 

[matt9923]

Re: can i add an alternator

To keep 12 volts with 2 batteries, connect positive to positive... and negative to negative. Most people end up frying items by wiring the batteries in series, creating 24 volts.

As for using the the charging system on the outboard to charge the deepcycle battery, I would not try it. You may be able to charge to the deepcycle battery by making long high speed runs, but you will end up burning up your stator.

I do disagree that you will burn your stator. Its going to put out what it can, it doesn't care if its deep cycle or starting. It will **** out what it can. I have 1 deep cycle for trolling and starting and 2 navigation lights. Its not going to charge it fast bu *** will keep it up during the day. Then when you get home if u use it hard you charge it up. Iv talked to a few people
(mechanics, electrical engine, other boaters) and this is what they say and i agree.
Matt