2001 Optimax 150 – Voltage Level Sensitivity

  • trophy19
    Maple Grove, MN
    Posts: 1206
    October 2, 2017 at 3:46 pm #1718324

    My son recently purchased a 2001 Tyee with a 150 Optimax. Seems to be a bit sensitive in regards to power levels; electronics show low voltage warnings when trimming motor up/down under power, etc.

    Mercury recommends 700 CCA or 1,000 MCA battery rating. The main battery currently in the boat is a marine starting battery in the 650 CCA range – reads 12.7V sitting..

    Could be a lot of reasons for the low voltage warning, – curious if anyone else has had similar issues with the Optimax motor being power level sensitive and if the battery rating is the main source of the issue.

    Thanks
    Pete

    igotone
    Posts: 1746
    October 2, 2017 at 4:19 pm #1718335

    How old is the battery ?

    trophy19
    Maple Grove, MN
    Posts: 1206
    October 2, 2017 at 4:23 pm #1718337

    2nd Year.

    munchy
    NULL
    Posts: 4931
    October 2, 2017 at 4:28 pm #1718339

    What wire size is feeding the motor and how long is it? Could just be a voltage drop from undersized/too long wire.

    Also someone could have put on some cheap thin metal crimp-on battery connectors.

    David Blais
    Posts: 766
    October 2, 2017 at 4:43 pm #1718344

    Have you checked the setting for the alarm? Mine was set at 12.5v

    blackbay
    mn
    Posts: 872
    October 2, 2017 at 6:48 pm #1718369

    Yes it is the cca of the battery that is the issue. The fuel pump takes a lot of juice even before the motor turns over. You really need as powerful of a battery as possible with an Optimax.

    mxskeeter
    SW Wisconsin
    Posts: 3810
    October 2, 2017 at 7:19 pm #1718374

    Low voltage causes all kinds of issues in a 12 volt system. None of them good. Buy a new starting battery with at least 950 cca. I bet it solves your problem.

    Iowaboy1
    Posts: 3791
    October 2, 2017 at 7:48 pm #1718380
    blackbay wrote:

    Yes it is the cca of the battery that is the issue. The fuel pump takes a lot of juice even before the motor turns over. You really need as powerful of a battery as possible with an Optimax.

    mxskeeter wrote:

    Low voltage causes all kinds of issues in a 12 volt system. None of them good. Buy a new starting battery with at least 950 cca. I bet it solves your problem.

    this is great advice and I will add have the charging system checked out to make sure a rectifier or regulator hasnt went south on you,if its not fully charging the battery as it should,even the biggest battery in the world wont spin it over after a while.

    onestout
    Hudson, WI
    Posts: 2698
    October 3, 2017 at 7:54 am #1718472

    Another important one on mercs is to use the nuts and not wing nuts on the battery posts. Make sure the connection is clean and tight. Not doing this is a big cause of thr voltage regulators burning up on the mercs. Just good practice for all battery connections.

    trophy19
    Maple Grove, MN
    Posts: 1206
    October 3, 2017 at 8:15 am #1718478

    Thanks Guys.

    I’ll pass your comments on to my son.

    Much appreciated.

    Pete

    trophy19
    Maple Grove, MN
    Posts: 1206
    October 3, 2017 at 8:59 am #1718492

    Follow-up question:

    Recommendation for a good marine starting battery that is at least 950 CCA?

    Thanks!

    Pete

    mark-bruzek
    Two Harbors, MN
    Posts: 3867
    October 3, 2017 at 9:09 am #1718495

    I would also state that it is not a good idea to run your graph’s power wires from the fuse block. It is best to run a designated setoff wires straight to the battery with an inline fuse installed.

    There are a lot of hack wire jobs out there on boats and many are performed by “dealerships” who tie into the fuse block just to save time.

    igotone
    Posts: 1746
    October 3, 2017 at 11:27 am #1718526

    Pete, lots of good info on here
    I should add I have the same motor on a 1898 Warrior

    If you have a 650 cca battery I guessing it is a group 24
    Go with at least a group 27 the 950’s are a group 31 I believe.

    I have had no issues with a 27 — I will also add that I changed the voltage alarm on my HDS 9 so that it does not go off. Easy fix.

    Optimax’s take a good battery for starting — They make one complete rotation to start.

    hope this helps,
    My 150 has been great on gas compared to the Mercury XRi I had !!!

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