View Single Post
Old 05-12-2014, 07:31 PM   #32
Delta Tango
Veteran Member
 
City: Gold Coast
Join Date: Mar 2014
Posts: 34
Quote:
Originally Posted by caltexflanc View Post
Funny thing, Vetus specifies what size battery to use for their thrusters by giving an amp hour (not a cranking amp) specification and range. They also note that if the capacity exceeds the top end of that range, and the cables are larger (or much shorter) than that specified in their table, the usage time must be reduced to avoid motor damage.
Vetus are wrong.
What the issue is with your comment on motor damage is like this - most providers of DC thruster make their specification based on an expected voltage loss. For example, Sidepower quote their performance in KG of thrust at 21vdc, other brands do the same so the run times are based on the voltage / amps = KG of thrust. If you increase the voltage at the thruster you also increase the current; Increase current you increase heat and therefore shorten run times (or potentially damage motor). The offshoot of all that is increase current = increase power with a shorter run time due to all being thermaly protected.
In my experience - Deep Cycle batteries have no place connected to a Bow Thruster of any brand.
I have watched my Clamp Meter tell me the story of just how poor they are 100 times.
DT
Delta Tango is offline   Reply With Quote