Originally ordered the 20 ProMariner because the old charger was a 20... but I have exchanged for a 40.
Battery Charger question...
- Thread starter SailFysh
- Start date
Yes, that troubled me finding a place for all those grounds. Power posts? Is that like a bus?
Alternatively move the charger connections to the posts with only a single connection.
You should put 60A MRBF fuses on them or even better option is to put dual post mrbf ( and leave on same battery) with 60 and 200+ (depending on wire size) on them. Wayt has a reasonable price on the dual post holders and fuses.
With a 40A charger you'll need bigger wire. I'm surprised your C310 has #10 for the charger, I'm pretty sure ours came with #4 from the factory.
No it's #10. I like the 40. Some folks are using the 20 with no problem so I think the 60 is too much for the way we use our boat.
For a 40A charger you'll want at least #8, and that's barely enough. #4 would be much better.
http://assets.bluesea.com/files/resources/reference/20010.pdf is the Blue Seas wiring size chart.
Just noticed I was only considering the distance one way... #4 it is. Now to figure out what size/type fuse and fuse holder. Promariner said 60 amp fuse on the 40 amp charger. But the wire chart shows much higher rated fuses for #4 wire. Guess stay with the promariner suggestion?
The fuse protects the wire, not the equipment, but it's ok to go lower, as long as you don't end up with nuisance trips. What you're really fusing for is if the wires short the battery. The charger would add it's 40A, but the battery would be the real gorilla in the room. Plus the fuse is at the battery end, not the charger. Using MRBF fuses (https://www.bluesea.com/products/5191/MRBF_Terminal_Fuse_Block_-_30_to_300A) either on the battery terminal, or even better, on something like their MaxiBus (250A) or PowerBar (600A), works well. I did that on our C27 and will be doing it on our C310.
I THINK YOU'RE REALLY overthinking this. Before you get wire cut, you want to see how big the charger can connect to. #6 wire and maxi fuses should serve you as well as it has on my B32. Your neg wire might not go the same route as your pos.
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I just installed the same 40A charger. I used #8. Probably overkill but if I need bigger later I only need to swap the charger not both
No doubt I've been overthinking it. Way too much good info available on sites like this. Helpful for sure but a fellow has to wade thru it to figure out what works best for him. Thanks again to all.
Didn't you read replies #10 & 11?
Consider the alternative.
Really? Wade through it? That's offensive to those of us who answered you, in great detail and with links.
Just STOP and do some reading of the materials we already gave you, and then you can ask more specific questions.
This dude didn't "get it" either, even though we spent a lot of time trying to explain it to him:
http://www.cruisersforum.com/forums/f14/dc-wiring-question-fuse-placement-182815.html
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Sorry you misunderstood Stu... I really appreciate all of the assistance. I believe I mentioned that several times. Believe me I have read every thread and post multiple times but since learning is mainly a hands on experience I am slow to put the info into practice. "Wade through it" simply means processing the vast amount of information and advice. Some have opinions about what worked for them that are in fact contradictory to advice offered by manufacturers... therefore I have to decide what works for me. Of course I want to be as close to "right" as possible. My sincere apologies to anyone who feels I don't appreciate the advice. The friendly offer of help on this forum is wonderful. I will always try to help others down the line.
Sorry if I misunderstood you. Thanks for the clarification.
Your quote is absolutely pertinent to my suggestion of asking more specific questions. Please let us know just what contradictory information you're getting and we're here to help.
FYI, we have all been in that position, and actually have solutions an, more importantly, REASONS for why things may be that way. Please don't think that you "have to decide what works for you" all alone. With your admittedly limited knowledge, it would be good to continue to tap into our experience to save you from reinventing the wheel. That's the beauty of this forum.
Ask away. In fact, you've peaked my curiosity about what those issues could be.
Just another tought for you to consider, if you don,t need the full 40 amps as tbe charger could send all that to one battery if only one battery is down, you can set the charger to a lower max amp output. Tech support at Promariner suggested that I set my 30 amp charger down to 20 for my two flooded batteries.
Tech support at ProMariner told me I didn't have to worry about the charger sending too much power to one battery bank because the charger assessed each battery independently and adjusts to what the battery needs.
Thanks all.
Thanks all.
While that may be true, here's what happens at the battery end:
Battery Acceptance by Stu http://c34.org/bbs/index.php/topic,4787.0.html
When in doubt, RTFM.
There is also Maine Sail's excellent writeup on this website and included below, which was included in reply #2 on page one of this thread. It's better than the manual, but RTFM, too.
The acceptance discussion comes from this topic which you might find helpful, in addition to Charlie Wing's book.
Electrical Systems 101 http://c34.org/bbs/index.php/topic,5977.0.html
Battery Acceptance by Stu http://c34.org/bbs/index.php/topic,4787.0.html
When in doubt, RTFM.
There is also Maine Sail's excellent writeup on this website and included below, which was included in reply #2 on page one of this thread. It's better than the manual, but RTFM, too.
The acceptance discussion comes from this topic which you might find helpful, in addition to Charlie Wing's book.
Electrical Systems 101 http://c34.org/bbs/index.php/topic,5977.0.html
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Ron, #6 wire @ 40 A is good for a round trip distance of 20' with a 3% voltage drop (65 feet round trip with a 10% drop, but you really don't want that much voltage drop when charging your batteries). I'm pretty sure the distance from the charger to the batteries will be more than 10'. As Maine Sail said earlier: "It is always better to err on the side of caution because terminations fuses etc. are not accounted for in the wiring voltage drop calculation. For a charging circuit the maximum circuit voltage drop should be no more than 3%. Ideally you want to aim for 2% or less. A 3% drop at 14.4V leaves you with just 13.97V at the batteries and can hinder charging performance."
Not overthinking, just doing the calculations so the wire gets sized correctly.
Leslie, #8 wire at 40 A is good for a round trip of 10' with a 3% voltage loss. Is the charger to battery less than 5' on a C36? Have you measured the voltage at your batteries to see what it's dropped to?
Not sure what you mean about swapping for bigger later?