Do I need dual cranking batteries?

[izoomie]

I've had mostly outboards but one 20' bowrider with a merc I/O I had came with dual batteries and the "battery1/battery2" switch. I'm pretty anal about keeping good quality charged batteries on my boat but should I consider installing the dual system on my 18' with 90 merc O/B?

I have a second battery for a trolling motor up front but they are completely separate circuits and I tend to drain that one while I'm fishing. Can't really rely on it to start anything.

 

[spdracr39]

Re: Do I need dual cranking batteries?

Not necessary by any means. It is solely for your piece of mind.

 

[Natesms]

Re: Do I need dual cranking batteries?

I only ran the duals for the main circuit when I have electronics pulling a lot of juice (AKA stereo with amps). It is good peace of mind but not required at all.

I don't know about your outboards, but my old one did virtually nothing when it came to recharging the batteries. The duals were handy if I didn't bother to charge it up, but I never went through a full battery in a day. I put in a smart charger and it was money well spent. I just plugged it in as soon as it got parked in the driveway and didn't worry about unplugging until I took it out again.

 

[MikeB0307]

Re: Do I need dual cranking batteries?

We only run one cranking battery on our boat and we're running a Merc 90. Never an issue. Save the weight and just make sure you've got a good battery.

 

[carey965]

Re: Do I need dual cranking batteries?

I run a cranking batt and a deep cycle on my 4.3 merc. But I also have a big stereo that i dont want to worry about when parked.

Normally I tend to start it on the cranking battery run it till I get to where I'm going so it gets topped up then when I stop I switch to my deep cycle and run off that for the rest of the day. Then that way if we are beached for awhile listening to tunes I know i can always start it back up by flicking the switch

 

[greenbush future]

Re: Do I need dual cranking batteries?

Depends on what waters you are on, the type of boating you do and all that. I felt so much better having a 2 battery system, but I do spend time on the great lakes and if you are stranded, it's not like you just wait for the wind or another boater to get you to shore. I also always had a kicker motor for fishing, but it did save my butt once or twice when I had engine failure or a dead cranking battery. Up to you in the end.

 

[Natesms]

Re: Do I need dual cranking batteries?

I run a cranking batt and a deep cycle on my 4.3 merc. But I also have a big stereo that i dont want to worry about when parked.

Normally I tend to start it on the cranking battery run it till I get to where I'm going so it gets topped up then when I stop I switch to my deep cycle and run off that for the rest of the day. Then that way if we are beached for awhile listening to tunes I know i can always start it back up by flicking the switch

Exactly what I did. On good weekends I'd drain the deep cycle to the point it couldn't even turn on the head unit anymore. Always had the starter though!

 

[izoomie]

Re: Do I need dual cranking batteries?

We only run one cranking battery on our boat and we're running a Merc 90. Never an issue. Save the weight and just make sure you've got a good battery.

Hey, I never even thought about the weight. Great thought. I also like the second battery idea to run the electronics while beached for the day.