Simple, at least for low-tech carb'd V6 outboards ... they really don't need the starting oommmpphhh that large inboards or diesel motors do. To me, it is the drain of running your depth, fish, vhf, gps, radar, lights, livewell pumps et all that puts the "discharge" into the battery. Note that some newer OBs, like high tech 2-stroke DI ones and newer 4-strokes, need more battery oommppph to make sure the computer starts up. Just always be sure and use at least the minimum your manual calls for. For example, Group 27s are more than enough for a older V6 outboard.Wild Bill":37jikh2y said:Dale-
What is the advantage of the combo batteries?
That is only true "if" you run with the battery switch on BOTH and then shut off the motor(s) ... the stronger battery will equalize into the weaker one.Wild Bill":37jikh2y said:Dale-
Second, everything I have alway read about batteries recommends to replace both at the same time because the older/weaker battery tends to drag down the newer battery.
That is a good point that I did not think of. Maybe I will get both batteries tested and if they are still fairly strong, buy one new one each year. If they are not both strong, I will get two new ones.I have seen new batteries fail, so I prefer the comfort of having an older, but known good battery, along with a new or newer one.
When running with the switch on BOTH and then shutting off the OBs, you run the risk of having the batteries equalize. Let's assume one is at 90% and the other is at 60%. It's a nice warm day and the OB fires easily, but you don't run that far and then you setup to drift or just stop and anchor. Your strong battery will discharge into the weaker battery ... so now you have 2 @ only 75% capacity, which may or my NOT be enough to start the OB, specially if you sat there for a few hours and ran the AM/FM radio and other electronics.rangerdog":6zkxhhj2 said:Let's talk about this "BOTH" issue. Pro's and cons. My dealer said to leave the switch in "BOTH". Why or why not?
No, if on 1 or 2 only that battery charges unless your boat and its systems have an isolation/combiner feature built in, which FWIW are now coming equipped on some of the newer OBs.Do both batteries charge when in "1" or "2"?
I'd say for starting and charging, but I myself DO NOT put it to BOTH to start the OB unless I try it on the one I'm running on and it isn't strong enough to fire the OB off ... which has never happended to me by the way.Is the switch only for starting?
I will run with the switch on BOTH when running offshore 10-20 miles in search of tuna, this way I know I'm kicking some charge into both batteries, since I'll be cruising along (seastate permitting) @ 4K RPMs or higher. If/when trolling, I'll still leave the switch on BOTH, but if I setup a slick or stop the boat and shutdown the motor, my practice is to immediately put the switch to position 1 or 2.Running on BOTH batteries, my addition to this topic: