Couple questions ?
When you say "
only works for 3 or 4 max thrusts" -- how long is each of those thrusts your talking about ?
How much rest time between thrusts ?
What brand Bow Thruster do you have ?
Plastic props or stainless steel props ?
I am presuming it is electric -- is that correct ? Some are Hydraulic.
If it is an Electric Thruster, (as I am presuming) -- how many volts is it supposed to operate with ? -
most likely - 12-V - or 24-V- or (could possible be 36-V - or 48-Volt - but I doubt it for 30 footer) ?
How many HP is it rated at ?
What diameter is your tunnel it is mounted in ?
Or is it the bolt on bow external type ?
What is the diameter of the prop in that tunnel ? -- I want to see how snug a fit the prop is to the tunnel - clearance from prop tips to tunnel wall is critical Tighter the fit the better, for top performance.
Does it have a single prop or dual prop design ?
Exactly what battery & size & how many do you have on the boat to operate the thruster ?
How old is that battery ?
Is it a starting battery or a deep cycle style battery or is it an AGM ?
When was it last tested with something like a quality state if the art Midtronics capacitance style battery tester ?
if so, when & what did it say about the battery ?
Is that battery a dedicated Thruster only battery or maybe Thruster & Windless only battery ?
Or is it shared - like the house battery, or engine starting battery, or - ??? - as well as thruster battery ?
How is that battery for your thruster recharged when at the dock on shore power ?
Is it a 4 stage charger that equalizes the battery on regular schedule ?
How is it recharged when under way ?
If charged by the alternator, - key item is - What kind of regular ? BALMAR or is it the stock internal regulator in the alternator ?
What CCA is the battery or batteries that you have running your bow Thruster ?
Are your batteries wired in series or parallel ? -- or is it just 1 battery ?
Example: - like two 6 volt golf cart batteries wired in series to get 12 volts, or are the batteries wired in parallel like two 12 volt group 24 , 27, or 31 batteries hooked positive to positive & negative to negative as they are wired in Parallel ? Or do you have a single or dual Heavy Duty dedicated "
8D-HD-T" batteries running the thruster ?
Are the battery terminals post style or are they terminal stud style battery connection points ?
If post style - what kind of adapters are you using to hook to the cables ?
Are your batteries a flooded lead acid type battery or an AGM type battery ?
What size coper cables do you have running from battery to the thruster motor ? Are the ends crimped or soldered ?
How long is the run from your battery to the thruster motor for each cable ?
How old is the system on your boat ?
What maintenance have you done to the system over the last 2 years, if any ?
-----------------------------------------------------------------------------------
I am a long time thruster advocate & had them on a dozen different boats over the years. Different brands & different styles & different sizes.
I currently have both a bow & stern thruster on my Kadey Krogen 42 & they work great.
they are -- WESMAR Dual Prop Bow Thruster-- that is 24-Volt & powered by dedicated battery pack of 4 group 31 AGM batteries - Series / Parallel wired -- for 24-volt.
----- 10 HP at bow & 13.5 HP at stern.
Love my Thrusters !
I can spin my boat 360 degrees with no issues.
These questions & your answers, will supply the needed info To help diagnose your issues & will help the team here at TF to assist you with your dilemma.
BTW - a picture is worth a 1000 words.
Thanks.
Alfa Mike