Other things to consider........This is FYI........... </p>
If you have a mercury 2.0L or 2.5L V-6 with a 40amp system with 2 regulators, you can install a battery isolator and wire it where 20 amps are charging the trolling motor batteries and 20 amps is charging the cranking battery every time you make a run. Mercury had a 9 amp (2.4L&2.0L),16 amp (2.4L&2.0L), and 40 amp (2.5L,2.4L,&2.0L) charging systems so 20 amps is still more than the 2 previous smaller charging systems and this will shorten the amount of time that it take to charge them with a onboard charger and keep them fresher on the water.</p>
The 2.4L version was a single regulator system and was JUNK and VERY expensive. I have converted a few of them to a 9amp system with no battery issues. </p>
On a OMC with a 35amp sytem, you can add a isolator and charge all 3 also, you will only have approx 11.6 amps going to your starting battery and 11.6 amps to each trolling motor battery. But the older charging systems on mercurys and OMC were only 9amp charging systems. Unless you have a TON of electronics. This will work well. I have done this to a 150 Johnson with no battery issues. This will still shorten the time needed to be on the onboard chargers. The mercury is just a better canidate for it due to the split system. </p>
Many people do not realize that the engines charging sytem can be done this way. There are also systems I have heard about that hooks up to the tow vehicles charging system to charge them while being towed to the lake. Some people have to drive great distance to go fishing and can utilize these. </p>
Hope this was useful to someone.emoToast </p>