How far can I push these deep cycles?

[84CJ7]

I have a particularily bad case of an old common problem, charging with an outboard. Anyone have and advice specific to this mess?<br /><br />I have a cuddy cruiser with an 84 Johnson 90 hp v4 on it and I believe that it is supposed to put out 10 amps, probably on a good day and at max rpm (have look that up again but I believe thats the correct number) which is obviously adequate for charging the starting battery and almost nothing else. Which leaves me wondering what to do with graphs, gps's, radios, lights and all the other crap I will need to put on the thing.<br /><br />I had planned to make trips on the mississippi overnight and the like, but iam not sure its possible unless I am stingy as hell with electricity. I suppose if iam not moving though, id likely be sleeping. I was planning on a group 24 starting battery with 2 group 27 or possibly group 31 (fits in a group 27 tray but is bigger and has more oomph) deep cycle batteries connected together (in 12v still since I don't have a trolling motor).<br />I had planned on getting one of those hummingbird sonar imagers if I could ever afford it but I think those things were supposed to be big power hogs too, I wouldnt know whether to put it on the starting battery since it would only be used when moving, or on the deep cycles.<br /><br />This boat was built in 1958, I wonder what in the hell they did for charging with the old batteries and motor they originally woulda had on it.<br /><br />Wish they made high output stators for old stuff.

 

[waterone1@aol.com]

Re: How far can I push these deep cycles?

While not a great setup, I don't think it will be as bad as you envision it. First thought, I like to have the starting battery only for starting <br />( I would not connect a depth sounder or sonar to it....what if you forget to turn it off). Although 10 amps of charging isn't a-lot to work with, I would still install a battery isolator so the engine can charge the deep cycles once the starting battery is charged on extended runs.<br /><br />You said that you didn't have a trolling motor...that is good. Other than the sonar, most of your other electronics won't draw much power (unless you do a crazy stereo with amplifiers and such). Even the VHF doesn't draw much unless you are transmitting. I would suggest changing your lights over to LED lights (much less power draw). I would also suggest installing an onboard battery charger for at home and if you spend the night in a marina slip.

 

[Boatist]

Re: How far can I push these deep cycles?

I agree, with no trolling motor you should have no problem keeping batteries charged.<br /><br />Thing that are big loads, Bilge Blower, any kind of incandesent lights, high power stereo, TV, 12 volt hair dryer. <br /><br />Your depth finder, VHF not talking on high power, and GPS will not be a problem for your 10 amp alternator.<br /><br />Unless your going to stay several days with out moving I do not think you need anything larger than a single group 27 battery.<br /><br />If you have access to power along your trip then take a battery charger and charge when you can.<br /><br />Expensive and noisy option would be a small portable generator.

 

[walleyehed]

Re: How far can I push these deep cycles?

6 or 9amp system and it charges 6/9 above about 4800RPM at best. a fully charged 27 will still take 3 and leave you with 6..."if" you have a 9amp system, not near enough to put any significant amount back.<br />The 6amp system was intended to take care of the starter battery only, and you WILL burn the stator and/or reg/rect out if you try to charge 3 batteries with it. In fact, you could very easily get into a situation where the demand of charge for the starter battery will be exceeded, and you'll lose that one.

 

[Silvertip]

Re: How far can I push these deep cycles?

Buy a jump-start pack and take it with in the event you do run out of juice. It will easily start the engine and can even serve as a portable power source for any on-shore activities. Charge it when you get back home. You don't have as much load as you think. As was suggested, pop for the biggest deep cycle you have room for. Use the starting battery for starting only and possibly bilge pump since its in the vicinity. Other stuff can go the deep cycle. If lighting is an issue, buy the new LED cabin lights that take very little power. Otherwise, a light or two will run for days on a deep cycle.

 

[84CJ7]

Re: How far can I push these deep cycles?

When I looked at parts stuff, mine listed a 10 amp stator, and it wasn't until 86 that the slash stuff started showing up. I'm sure its a WOT still though.<br /><br />This is an outboard so no blowers, at the moment it has no tv or regular radio and I won't be putting them in any time soon. It has several small lights that are original to the boat, I will minimize their usage and look into adding a main LED cabin light. I can run the accessories off the deep cycle, if I do add a trolling motor, it wont be for trolling, only as an emergency backup motor. I already picked a 70 lbs thrust 24 volt transom mount as the one I would get.<br />I have room for 6 group 31 batteries or more without squeezing anything in if I felt like it, but I think I will go with 2 deep cycles, wired for 12 volts normally for greater capacity, but with a jumper I can add in case I need 24 volts for the trolling motor, unless you can wire batteries for both series and parallel at the same time but for some reason I get the feeling that shorts or overloads something, maybe im wrong.<br />I also have a 3 bank 20 amp distributed charger picked out, I forget the brand.<br /><br />If you are having trouble picturing such an odd boat this is it:<br /> http://www.shareaproject.com/pages/projectTut,p,160,00.html <br />It is aluminum and so light it went from a manageably heavy 2 handed lift at the tongue to a manageably heavy one handed lift with the motor on it.