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Random Quote: There are two ways to do everything....right and over.
Hi all,
I have an 18'CC with a Suzuki DF115. I want to move the battery to the CC to get the weight out of the stern. I bought it with two batteries mounted under the stern jump seats. I think the weight of the 4 stroke and two batteries might be a little much. I have lights, VHF, Bilge pump and GPS/sounder for electronics. Do I need two batteries?
Jay
The question is, where do you take the boat? What would happen if your single battery went dead? How often/how long do you use your electronics/lights without the engine running?
From a 'technical' standpoint you're fine with one battery (although if you're only going with one, I'd make it a big one). From a common sense standpoint, it's all up to you, where you go out, what kind of conditions you go out in.
Honestly I think you'd be fine with a single battery. It's not like you have a 1972 outboard that you have to crank for 15 minutes to get it to start. Assuming you don't run for hours on end at night, just use common sense and you'll be fine. Two would be great for redundancy, but may be overkill depending on what you do in the boat. And before someone says it's a safety issue and he should have two no matter what - the safety issue could very well be the extra 50 lbs of battery #2 he's dragging around.
I have a 18' CC with twin batteries. Personally I wound never go out on 1 battery. there are just too many things that might happen; water in fuel, depth finder and GPS running down battery, engine problems that require a lot of cranking, a short taking out 1 battery, etc. Better safe than sorry!
the weight of another battery under your console shouldnt affect anything
get a plain old marine deep cycle wet battery at wal-mart, and run your electronics & accessories to it
you could also add a battery combiner between the two, so that your engine will keep them both charged
I did the same thing in a 17' whaler. The tinned wire can be expensive ( I upsized to the next larger size ) but did not want any splices in the bilge. Instead of a second battery, I have a jump battery from wal mart that I bring long.
__________________
"Of all tyrannies a tyranny sincerely exercised for the good
of its victim may be the most oppressive." ~ C.S.Lewis
I've got an 18CC and always carry an extra under the console. I have been saved more than once having the extra - once with a 4 and 8 year old about 2 miles off dift fishing. Trust me, take the extra.
Two batteries on an 18ft boat is overkill. Hard to imagine current draw on that boat that could routinely drain one battery. I have a Boston Whaler 17ft Montauk. Rather than wire in and carry a full extra battery, I carry one of those $50 portable battery packs. I can jump start my starting battery if I ever need it. Plus, I can be a hero if one of my fellow boaters gets caught with a dead battery.
Jim
I recently hung a zuke 140 on the back of my wellcraft 18 cc and moved both batts under the console. The motor weighs 40 lbs. more than the previous Rude 115. My console has a deep storage compartment that looks as it was made for a dual battery setup. I did not move the switch, but did run a little heavier guage cable. Keep both batts! ya might need em and moving them to my console only improved stability. jefe. By the way the performance difference was pretty dramtatic, especially in midrange torque, it is much more responsive. You will love your zuke!
I recently hung a zuke 140 on the back of my wellcraft 18 cc and moved both batts under the console. The motor weighs 40 lbs. more than the previous Rude 115. My console has a deep storage compartment that looks as it was made for a dual battery setup. I did not move the switch, but did run a little heavier guage cable. Keep both batts! ya might need em and moving them to my console only improved stability. jefe. By the way the performance difference was pretty dramtatic, especially in midrange torque, it is much more responsive. You will love your zuke!
Hey, that's exactly what i'm thinking. At the dock, the boat seems low and seems to drag it's but on acceleating from stop. Definately putting 'tabs' on in the spring. I've just been thinking of this over the winter and haven't checked the tube size under the deck. Not even sure there is room to run the cables. I think there is only one tube and it may be full. When the cover comes off, i'll know more.
Maybe take some pix of the job.
Thanks all
Jay
I do not want to go to far off topic but can the new outboards run without a battery? The old carb'd 2s could run without a so if it was dead you could rope start them, is it the same with new o/b motors and their electrical systems? If not then a second battery may be needed, not just a jump battery. I know some of the new cars will not run with a week battery.
__________________
"Of all tyrannies a tyranny sincerely exercised for the good
of its victim may be the most oppressive." ~ C.S.Lewis
I would leave the rope start as the last resort after both bat have died. Ever tried this before, I did on 115 merc and 120 Johnson (2stk) very difficult to do. When the eng is warm they will fire that is if you do not strike yourself or someone else on the boat. Also imagine you are in 3-5 foot seas and you are taking the cowling off and rope starting? Think again, 2 bat at a min plus bat switch. It would be hard enough to hook up the bat jump start in rough seas and what do you do with the bat box? Mine are under the cons and boxed in bat holders and strapped. It would take several min just to take the cap off and hook the jump start. IMHO the bat jump start is a great tools and ins policy to have on board but for ease of use I rely on a twin bat system.
as cgrand mentioned above, I would go with two batteries, and a battery combiner. Run all your electronics & accessories off of 1 battery (decent size deep cycle), and the motor only off of the starting battery. When you crank the boat, both charge without having to mess with any switches, and your electronics can't drain your cranking battery. However, you can parallel them & crank your motor should you somehow manage to run it dead. Once it is all hooked up it is so simple that you don't even have to think about it.
as cgrand mentioned above, I would go with two batteries, and a battery combiner. Run all your electronics & accessories off of 1 battery (decent size deep cycle), and the motor only off of the starting battery. When you crank the boat, both charge without having to mess with any switches, and your electronics can't drain your cranking battery. However, you can parallel them & crank your motor should you somehow manage to run it dead. Once it is all hooked up it is so simple that you don't even have to think about it.
autobaun70, do you use a combiner with the battery switch? I just did a search and see that both are used. Is this so both batteries get charged even with the switch one 1 or 2?
Jay
do you use a single or dual switch with the combiner?
charging works without a switch just fine
if you needed to start off the house battery though you'd need a switch
best way is three on/off switches...one for each battery & one to parallel
BEP Marine has a sweet set-up cluster that includes the combiner & three switches
i just put that on my boat and it really makes things nice
18' CC, single battery OK? 
