Page 1 of 2 12 LastLast
Results 1 to 20 of 24
  1. #1
    Member
    Join Date
    Jul 2005
    Location
    Lake Lanier, GA
    Posts
    746

    Best Way to Charge 5th “House” Battery?

    Long story short, my dealer is adding a 5th house battery to my boat which is equipped with a 36V Ulterra, a 300HP V8 Verado, and a 15HP EFI Kicker. I have an MK460 Minn Kota digital on board charger, which puts out 15 amps on each of 4 banks.

    What is the best way to charge the 5th battery:

    1. Split one bank of the MK 460 so 7.5 amps is used to charge the starting battery and 7.5 amps is used to charge the house battery?
    - This seems like the easiest way to keep both batteries charged, and 7.5 amps per bank is not too shabby. But what’s the right way to wire things to do this?

    2. Add a second single bank on board charger and connect it to the back side of the existing charging plug so I still only have to run one cord to the boat to charge everything?
    -More expensive and complicated, but will result in quicker charge times.

    Any thoughts/suggestions would be greatly appreciated.
    2020 Triton 216 Fishunter
    Mercury V8 300 Verado (2B646603)

  2. Member
    Join Date
    Nov 2007
    Location
    Republic, MO
    Posts
    2,910
    #2
    I am running a 5th battery. I am doing it the old fashioned way with an external charger.

  3. Member
    Join Date
    Jul 2005
    Location
    Lake Lanier, GA
    Posts
    746
    #3
    That would work but I would prefer not to do that if possible. I just read an old post saying Option 1 (hooking up two batteries in parallel to split the charging amperage from one bank) van shorten the life of the batteries as the higher charged battery will continually be drained by the lower charged as they try to equalize while in a non-charging state.

    Assuming that’s true, I’m thinking adding a single bank 10 amp Minn Kota MK 110 PC and wiring it up to the back of the existing charging receptacle/plug (that’s also connected to my existing MK 460 PC) is probably money well spent.
    2020 Triton 216 Fishunter
    Mercury V8 300 Verado (2B646603)

  4. BBC SPONSOR / PHOENIX MOD DREWTICK's Avatar
    Join Date
    Mar 2014
    Location
    Vass, NC
    Posts
    7,827
    #4
    Quote Originally Posted by rpr View Post
    That would work but I would prefer not to do that if possible. I just read an old post saying Option 1 (hooking up two batteries in parallel to split the charging amperage from one bank) van shorten the life of the batteries as the higher charged battery will continually be drained by the lower charged as they try to equalize while in a non-charging state.

    Assuming that’s true, I’m thinking adding a single bank 10 amp Minn Kota MK 110 PC and wiring it up to the back of the existing charging receptacle/plug (that’s also connected to my existing MK 460 PC) is probably money well spent.
    these are handy for that second charger to the built in receptacle https://www.amazon.com/Cablelera-Pow...s%2C157&sr=8-3
    Drewcraft Specializes in Lithium Batteries and Chargers, We carry all Brands of Trolling Motors and Graphs, Minnkota, Lowrance, Garmin, Motorguide
    910-722-0001 call or text
    info@drewcraft.com

  5. Member
    Join Date
    Jul 2005
    Location
    Lake Lanier, GA
    Posts
    746
    #5
    Great, thanks!
    2020 Triton 216 Fishunter
    Mercury V8 300 Verado (2B646603)

  6. Member
    Join Date
    Feb 2007
    Location
    Collinsville, IL
    Posts
    7,203
    #6
    Get a DualPro “charge on the Run” Charger. When your cranking battery is full the extra current goes to the other battery. I have a 3 bank that they don’t make anymore but it definately helps when making long runs and fishing in the wind.

  7. Member
    Join Date
    Jun 2004
    Location
    Flowery Branch, Ga.
    Posts
    5,990
    #7
    I run a 5th battery, but added the same 2 pin connectors on each battery, so when one is charged, I just plug the other in. I use connector like the ones used on motorcycle battery tenders. (from my old Harley's)
    The trollers have their own 3 bank charger.

  8. Member bloodman's Avatar
    Join Date
    Oct 2008
    Location
    Belvidere, Il
    Posts
    6,005
    #8
    Quit the band aids and get a 1 bank charger

  9. Member
    Join Date
    Mar 2006
    Location
    Beaufort
    Posts
    1,110
    #9
    Quote Originally Posted by rpr View Post
    That would work but I would prefer not to do that if possible. I just read an old post saying Option 1 (hooking up two batteries in parallel to split the charging amperage from one bank) van shorten the life of the batteries as the higher charged battery will continually be drained by the lower charged as they try to equalize while in a non-charging state.

    Assuming that’s true, I’m thinking adding a single bank 10 amp Minn Kota MK 110 PC and wiring it up to the back of the existing charging receptacle/plug (that’s also connected to my existing MK 460 PC) is probably money well spent.
    But that "old post" was entirely WRONG, your Assumption is NOT true. How can one battery be continually drained by the lower, a few seconds after the initial installation they will be at the SAME voltage, they will be at the SAME level of charge and no more battery-to-battery current will be flowing.

    Nothing other than a couple of jumpers is all you need to add the battery.

    It will actually EXTEND battery life. With separate batteries discharging individually into loads the depth of discharge will not be matched and one battery will discharge deeper which shortens its life. With the batteries in parallel the depth of discharge is going to be the same and less for one of the batteries.

    The source of this misconception about batteries in parallel is due to the fact that if one battery fails it will draw current from the good one. The good one will not be destroyed but all you have to do is disconnect the faulty one and you still have one working battery, just as you would had you used two independent batteries and one died.

  10. Member
    Join Date
    Apr 2012
    Location
    Insomnia, near Seaford Delaware
    Posts
    35,516
    #10
    Of course the lower battery will draw from the higher battery until they equalize. Do you run the House battery in parallel with your motor battery or just use it to power your accessories?
    What is the size of your motor battery and what size is the House battery?
    If it was my boat I think I'd run dual motor batteries of equal size and vintage, in parallel.

  11. Member
    Join Date
    Apr 2008
    Location
    Lakeview,AR.
    Posts
    7,994
    #11
    +1 Keep it simple
    Quote Originally Posted by bloodman View Post
    Quit the band aids and get a 1 bank charger
    Tell me where has a slow movin' once quick draw outlaw got to go

  12. Member
    Join Date
    Jun 2004
    Location
    Flowery Branch, Ga.
    Posts
    5,990
    #12
    Different size batteries wired in parallel will drop charge and drop voltage at the same rate. Current draw % will match battery size, but voltage will be the same.

  13. Member
    Join Date
    Jul 2005
    Location
    Lake Lanier, GA
    Posts
    746
    #13
    I decided to add a MinnKota MK110PC (10-amp) single bank charger for the 5th battery. This will be wired to the existing charge receptacle with a splitter and then directly to the 5th battery. Plug in one cord when I pull back in to the slip and I’m done.

    Many thanks for all the feedback.
    2020 Triton 216 Fishunter
    Mercury V8 300 Verado (2B646603)

  14. Member bloodman's Avatar
    Join Date
    Oct 2008
    Location
    Belvidere, Il
    Posts
    6,005
    #14
    Quote Originally Posted by rpr View Post
    I decided to add a MinnKota MK110PC (10-amp) single bank charger for the 5th battery. This will be wired to the existing charge receptacle with a splitter and then directly to the 5th battery. Plug in one cord when I pull back in to the slip and I’m done.

    Many thanks for all the feedback.
    There ya go

  15. Member
    Join Date
    Jul 2005
    Location
    Lake Lanier, GA
    Posts
    746
    #15
    My dealer installed the MK110PC and used the splitter in the above post so both chargers can run off of one cord. However, I was just looking at MinnKota’s specs on these chargers (not on their website, but in the manual) and they list the input current of the MK460PC as 14 amps and the 110PC at 2.4 amps. That’s a combined 16.4 amps which exceeds the rating of the splitter (13 amps) as well as the heaviest duty extension cord I can find (15 amps).

    Unless I’m missing something, I’m going to have to rethink this and use two extension cords to plug in each charger separately and hope my outlet at the dock has a 20-amp GFCI as opposed to a 15-amp.

    I’m not very comfortable with electrical issues. Would you guys agree?
    2020 Triton 216 Fishunter
    Mercury V8 300 Verado (2B646603)

  16. Member
    Join Date
    Jun 2010
    Location
    batesville, ar
    Posts
    284
    #16
    Use a combiner between the ignition battery and the house battery.

  17. Member
    Join Date
    Jul 2005
    Location
    Lake Lanier, GA
    Posts
    746
    #17
    Yes, they did install the Merc isolator Kit, which some refer to as a combiner. Granted, I’m far from an expert on these isolators/combiners, but I don’t think that changes the fact that the MK460 plus the 110PC combined on a single charging cord with a splitter can draw up to 16.4 amps, which is more than the rated current of the splitter and the cord.
    2020 Triton 216 Fishunter
    Mercury V8 300 Verado (2B646603)

  18. Member
    Join Date
    Jun 2010
    Location
    batesville, ar
    Posts
    284
    #18
    Quote Originally Posted by rpr View Post
    Yes, they did install the Merc isolator Kit, which some refer to as a combiner. Granted, I’m far from an expert on these isolators/combiners, but I don’t think that changes the fact that the MK460 plus the 110PC combined on a single charging cord with a splitter can draw up to 16.4 amps, which is more than the rated current of the splitter and the cord.
    With the combiner, I would question whether you even need the second charger.

  19. BBC SPONSOR / PHOENIX MOD DREWTICK's Avatar
    Join Date
    Mar 2014
    Location
    Vass, NC
    Posts
    7,827
    #19
    Quote Originally Posted by rpr View Post
    Yes, they did install the Merc isolator Kit, which some refer to as a combiner. Granted, I’m far from an expert on these isolators/combiners, but I don’t think that changes the fact that the MK460 plus the 110PC combined on a single charging cord with a splitter can draw up to 16.4 amps, which is more than the rated current of the splitter and the cord.
    those are peak amps, if you were to put an amp probe on that AC circuit after the first few minutes of charge you would probably not see over 10 to 12amps, also even using 2 cords more than likely you would still be on the same circuit anyway unless you have dedicated circuits or a 20amp circuit in your shop. most garages are on a 15amp ground fault circuit wired in 14/2, I would not encourage anything unsafe or over the limits but you can always install a 15amp ground fault receptacle where you plug in. they are pretty sensitive and will trip pretty easy.
    Drewcraft Specializes in Lithium Batteries and Chargers, We carry all Brands of Trolling Motors and Graphs, Minnkota, Lowrance, Garmin, Motorguide
    910-722-0001 call or text
    info@drewcraft.com

  20. Member
    Join Date
    Oct 2005
    Location
    Oaks, PA
    Posts
    1,159
    #20
    How about one of these? https://www.wirthco.com/battery-doct...series/150-amp It will charge you house battery when your motor is running and when the on board charger is charging.

Page 1 of 2 12 LastLast