Charging a trolling motor Battery

Discussion in 'Boating' started by Bigones, Jun 20, 2006.

  1. Bigones

    Bigones New Member

    Messages:
    161
    State:
    Ohio
    Howdy brothers, I have a question for ya. I have an onboard charger that will charge two batteries. The trouble is I changed trolling motors from a 12v to a 24v so I now have 3 batteries 2 for the trolling motor and one for the motor. If I run some wire from the the positive to the positive and negitive to the negitive on the trolling motor batteries will this charge both batteries or will I have to charge one of them seperately? I have the charger hooked to my cranking battery and one of the trolling. I was just thinking if I hooked them in a series that it would charge both. What do yall think?
     
  2. laidbck111

    laidbck111 New Member

    I'm no expert but it sounds like you would be pulling to much on the charger. like thoses guys with the thumping radio's some them pull so much they had to install two, three and four extra altenators and batteries just to keep up with demand. I think I would just charge them one at a time and always strat with fully charged batteries.
     

  3. Fastman

    Fastman New Member

    Messages:
    75
    State:
    Arnold, Mo
    I have done quite a bit of reading on this subject and as I understand it, you cannot charge 3 batterys with a dual charger.
    Your trolling motor is 24V. You cannot charge them with a single 12V lead. If you wire them in series it will be a 12V system, but the trolling motor will only get half the juice. Also it would be a dead short.
    I would suggest getting another single onboard charger and putting it on your starting battery and use the existing dual for the trolling motor batteries. You want to make sure they are charged and maintained equally. If not it will cause premature failure. Better to take care of them now.
    Fastman
     
  4. duxsrus

    duxsrus New Member

    Messages:
    1,014
    State:
    SW Ohio
    Depending on the size of the alternator in your outboard and if you have many accessories wired to your starting battery, you should be able to let your motor keep your starting battery topped off and use your dual bank onboard charger just to charge your two trolling batteries. Or just buy an inexpesive single charger for the starting battery.
     
  5. catseeman

    catseeman New Member

    Messages:
    1,189
    State:
    Indianapolis, Indiana
    you should have a sperate charer for the starting battery. I bought a inexpensive 2 amp trickle charger for my starter battery. be sure and get automatic shut off. Idon't have an alternator on he engine so i charge after every trip.
     
  6. rcneman

    rcneman New Member

    Messages:
    482
    State:
    TN
    do you charge your battery/s every time you get off the water?
     
  7. Fastman

    Fastman New Member

    Messages:
    75
    State:
    Arnold, Mo
    I do. Storing batteries in a partially (or fully) dischaged state sucks life outta them, fast.
    I boat all day, then when I come in at night they are on the charger all night. Its actually a smart charger/maintainer, 5/5/5. It quick charges them @ 5A per battery. As the batteries come up to full charge individually, it slows the rate to a 'top-off' mode. After topping off, it goes to a 'maintain' mode. I can leave mine plugged in all the time. 24/7/365 I dont have to worry about overcharging.
    Remember, batteries are a investment. Take care of them and they will take care of you.
    Fastman
     
  8. rcneman

    rcneman New Member

    Messages:
    482
    State:
    TN
    wow, i do not have the in-depth knowledge that you seem to have, but i have learned to put the slow-charge on battery whenever the trailer is sittin in the back yard...lol

    I hook up my cheap $40 charger and put it on it's lowest settin ( 2 amp slo charge) and let it do it's thang all night long...seems to do the trick.

    cyas
    rc
     
  9. Umba

    Umba New Member

    Messages:
    46
    State:
    WI
    Fastman,
    I thought series gave you 24v and paralel gave you 12v,am I wrong?
    Umba
     
  10. Fastman

    Fastman New Member

    Messages:
    75
    State:
    Arnold, Mo
    Ummm.. yup your right, my mistake. I was apperantly brain dead that day. Good catch.
     
  11. Mr.T

    Mr.T Active Member

    Messages:
    2,554
    State:
    MO
    I'm late to the party, but...

    I'd put the 2 trolling motor batteries on the onboard charger and then top off the starting battery once in a while with a separate charger if needed. The alternator on your outboard will do a fine job of keeping the starting battery charged; if you find that you've not been fishing in 3 or 4 weeks, top it off with a charger prior to heading out.

    If you don't think that's good enough (and it is, BTW), then sell the 2-bank charger and install a 3-bank charger instead.

    The onboard chargers have separate, electrically isolated charging circuits for each battery so it doesn't matter if the batteries are tied together in series or parallel configuration; the charging circuit only sees the one battery that it's connected to.
     
  12. PeZ

    PeZ New Member

    Messages:
    757
    State:
    Oklahoma
    I seen a solar panel battery charger the other day looks like it would work good anyone seen or tried these solar panel battery chargers?
     
  13. olefin

    olefin New Member

    Messages:
    3,908
    State:
    Texas
    I have an Guest 2 battery onboard charger for starting and trolling battery. It stays plugged in all the time at my dock when I'm not in the lake. But both batteries are 12 V.