1998 Johnson 130HP Alternator charging question

sdverne

Cadet
Joined
Apr 3, 2011
Messages
15
So this is my problem, the alternator on this engine doesn't have enough amperage to keep my batteries charged to run my boats electronics, bait tank, stereo, lighting etc. Currently have 2 standard deep cycle batteries w/selector switch. Have it so that one battery is used as a backup, so everything is running on one battery (including starting) I know I need to change it so that I use one battery for starting and another for the rest of my stuff. My question is this: Should I go to 2- 6 volt batteries to run the electronics and everything else. And if so could I get away with 2 flooded cell batteries, like a Trojan T-125 or do I have to go with 2- 6 volt AGMs? lets face it the AGMs are twice as much, so if I could go with the T-125s it would be better. Thanks ahead of time for any input.
 

etracer68

Ensign
Joined
Oct 11, 2009
Messages
906
Re: 1998 Johnson 130HP Alternator charging question

Ok I see you have a outboard, they dont have alot of charging power. I would check the volts at the battery before starting, it should be 12.5, after starting motor it should be 13.5 plus. Two 6 volt batterys wont help. I would have the largest cranking amp 12 volt that will fit.
 
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dew2

Senior Chief Petty Officer
Joined
May 6, 2010
Messages
674
Re: 1998 Johnson 130HP Alternator charging question

If you can afford three batteries and the size of the boat wont hamper storage area,I would get one battery for a start the motor batt (marine start) Then I would go to walmart and get two 12V large ah batts and wire them parallel which has 2 12V battes supplying 12 volts with twice the run time.
My larger fishing boat has a start batt (walmart), then a walmart (really good batteries and great warranty)12 volt deep cycle 185 ah,I run a GPS, 2 sonar units,after dark running lights,2 rope light floor lights and a spot light,and a 12 V 55 lb minnkota elec.motor.I dont have to charge the accessory batt more than once a week. I fish sometimes 2-3 times a day and the elec motor is used on low most the time out, 5 days a week.Not much night fishing.The start batt only gets charged every other week.
2 6 Volts are a waste of time you have to wire then series and then they will supply 12 V just go 12 V batts all the way around. The motor takes the least of your power with your set up, starting takes little juice unless your motor isnt running correctly.
 

SparkieBoat

Captain
Joined
Aug 17, 2009
Messages
3,643
Re: 1998 Johnson 130HP Alternator charging question

an out board motor does not produce a lot of charging..most set ups I have seen are like Dew2 has described..get an onboard charger and just plug it in every time you get in from fishing. the 2 batteries should last a full day and run all the electronics you need with in reason. use a separate battery for cranking, because you dont want to paddle back to the ramp.
 
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