Martin, engine start battery..is there on or two? Also should a person change out their thruster battery as well? My boat is the same year and model as yours.
thanks!
On the R27
- The engine battery is starboard side aft. 900 CCA, AGM, with 5/16” lugs.
- The thruster battery is on the port side, aft, Universal deep cycle 110ah, 550 CCA. 5/16” lugs.
(On the NW edition, the thruster battery is port side all the way forward, in front of the house batteries).
The Yamaha F300 requires 680 CCA min to start.
The end of this season I’m buying two engine starting batteries, AGM, each with at least 900 MCA. One will replace my engine start, the other will replace my thruster battery. Thus, I’ll have a spare engine start battery onboard. Thrusters operate similar to engine starting (large bursts, short duration), making a starting battery a good choice for thrusters.
I’ll also re-do the battery cables as they’ll all be 5/16” lugs and most new batteries today are 3/8” lugs. Do not drill out the 1/16” to make 5/16” into 3/8”. That removes the tin, which covers the copper. Exposed copper and salt water are bad, especially on electrical.
I haven’t picked a specific battery and am open to suggestions on brands. If I could find a G31, AGM, Engine Starting battery with at least 900 CCA, and it had 5/16” lugs, that’d save me some time and effort on remaking. Else, 3/8” lugs and I’ll make it work.
