I've been using using the CruzPro CC35 PWM controller http://www.cruzpro.com/cc35.html for almost a year, and I'm happy. Do any of you experts have opinions on it? Bulk charge to 14.5, absorption for 30 minutes, then float at 13.6. I have a 260ah house bank (2x Trojan 145 wet), and 50w Kyocera panel on the stern rail, which I can aim at the sun.
Onboard charger or solar charger?
- Thread starter captrick
- Start date
Maine Sail
Member III
If it is a true PWM it should be fine. You just don't want a "shunting" controller. My only concern would be the time limit on absorption voltage. With voltage comes current though your well below acceptance anyway so your panel should still be pushing max current when needed even at 13.6V float until the bank tapers it..
I would be curious to see the difference in current flow when it goes from "bulk" to "float", if any. These pre-determined and timed acceptance phases often wind up as a compromise especially as the bank gets bigger. Balmar is famous for "pre-determined" absorption phases that need to be tuned for the bank you're working with, though few take the time to do it..
According to my LinkPro, in bulk I'm usually getting 3.3-3.4 amps--though I've seen it hit 3.6, which sounds pretty high for a 50-watt panel. That tapers to .1-.2 or .3 amps, and rapidly fluctuates (CruzPro tech support says the fluctuation is the PWM in action). Since Trojan recommends a float of 3.2, I emailed tech support and they sent a schematic showing which resistor to replace. I haven't made any modifications--yet.
Maine Sail
Member III
If that 0.1 - 0.3A is when the battery is 100% full that's fine but if it is doing that before full you're getting less out of it than you could. PWM should appear on the LINK as constant current & voltage flowing. The pulses should be faster than the monitor can pick up..
Mainsail - answers to your points
After further review, solar will go straight to house batts for now. Back up will charge from alternator while switch is on both while motoring. Will be adding an echo or other charge back into the system later, but I think this will be good for now. (I am going to complete a wiring diagram this weekend and will post for follow up).
Size was based on the below energy budget (this is not yet perfect, but I think it is pretty accurate). My house bank is (2)75ahr for 150ahr total. I don't want to start with an excessively large/heavy panel, so I determined a 50-60watt producing roughly 3a will be good. Will be adding refrig and will parrallell a second panel in later to suplement when on anchor, etc.
Still determining mount. Will be flat on a pole off of stern rail. Am looking into an articulating head of some kind to point panel when convenient.
South Texas - 5 hours is conservative most of the year and probably accurate for the winter months. Lot's of sunny days. Would appreciate your opinion on the energy budget as a starting point.
Will be topping off the backup periodically by running motor on "both" in and out of the harbor, etc.
Advice taken on controller - will not go shunting as I need max efficiency with a smaller house bank (150). Will look into the recommended controllers. Thanks.
Will be looking into panel options from the reccommended vendors. Will verify warranty on UL solar.
Mount on pole on stern rail, up above bimini. Should be little or no shade most of the time.
Energy budget assuming a 60w that produces 3.1a at peak:
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Thanks again to everyone. I think I am almost there and am sure to install a much better and effective system based on your help.
Rick
After further review, solar will go straight to house batts for now. Back up will charge from alternator while switch is on both while motoring. Will be adding an echo or other charge back into the system later, but I think this will be good for now. (I am going to complete a wiring diagram this weekend and will post for follow up).
Size was based on the below energy budget (this is not yet perfect, but I think it is pretty accurate). My house bank is (2)75ahr for 150ahr total. I don't want to start with an excessively large/heavy panel, so I determined a 50-60watt producing roughly 3a will be good. Will be adding refrig and will parrallell a second panel in later to suplement when on anchor, etc.
Still determining mount. Will be flat on a pole off of stern rail. Am looking into an articulating head of some kind to point panel when convenient.
South Texas - 5 hours is conservative most of the year and probably accurate for the winter months. Lot's of sunny days. Would appreciate your opinion on the energy budget as a starting point.
Will be topping off the backup periodically by running motor on "both" in and out of the harbor, etc.
Advice taken on controller - will not go shunting as I need max efficiency with a smaller house bank (150). Will look into the recommended controllers. Thanks.
Will be looking into panel options from the reccommended vendors. Will verify warranty on UL solar.
Mount on pole on stern rail, up above bimini. Should be little or no shade most of the time.
Energy budget assuming a 60w that produces 3.1a at peak:
| Energy Budget - Solace | |||||||||
| October 1, 2011 | |||||||||
| Daysail | Overnight (per 1 day/1 night) | ||||||||
| Equipment | Amps | Qty. | Hrs/Day | Load | Qty. | Hrs/Day | Load | ||
| Autopilot | 2 | 1 | 4 | 8 | 1 | 4 | 8 | ||
| VHF | 1.5 | 1 | 2 | 3 | 1 | 2 | 3 | ||
| Depth Guage | 0.3 | 1 | 6 | 1.8 | 1 | 6 | 1.8 | ||
| Knot Meter | 0.1 | 1 | 6 | 0.6 | 1 | 6 | 0.6 | ||
| GPS | 1 | 1 | 5 | 5 | 1 | 5 | 5 | ||
| Stereo | 3.5 | 1 | 5 | 17.5 | 1 | 7 | 24.5 | ||
| Cabin Lights | 1 | 1 | 0 | 0 | 2 | 3 | 6 | ||
| Nav Lights | 1 | 2 | 0 | 0 | 2 | 1 | 2 | ||
| Anchor Light | 0.5 | 1 | 0 | 0 | 1 | 8 | 4 | ||
| Masthead Light | 0.42 | 1 | 0 | 0 | 1 | 1 | 0.42 | ||
| Foredeck Light | 1 | 1 | 0 | 0 | 1 | 1 | 1 | ||
| Bilge Pump | 1.9 | 1 | 0.16 | 0.304 | 1 | 0.33 | 0.627 | ||
| Cabin Fan | 0.59 | 1 | 2 | 1.18 | 1 | 5 | 2.95 | ||
| Refrigeration | 0 | 0 | |||||||
| Daily Amp Hours Used | 37.384 | 59.897 | |||||||
| Replinishment | Amps | Qty. | Hrs/Day | Charge | Qty. | Hrs/Day | Charge | ||
| Alternator | 30 | 1 | 0.75 | 22.5 | 1 | 1 | 30 | ||
| Solar Panel | 3.1 | 1 | 5 | 15.5 | 1 | 5 | 15.5 | ||
| Total Amps Replaced | 38 | 45.5 | |||||||
| Net Charge | 0.616 | (14.40) |
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Thanks again to everyone. I think I am almost there and am sure to install a much better and effective system based on your help.
Rick
Maine Sail
Member III
Rick,
That will work if you start from 100% SOC and only do one night. If you go more than one night your cycling between 50% & 80%. The last 15-20% takes many hours, like ten+, to get the bank back to full because of acceptance tapering.
If you add a battery monitor you may likely find that if you are using less or more than your energy budget. I often find customers have estimated in excess of 25% or more variance, sometimes in favor of the batteries, sometimes not...
Using the "cruisers rule", cycling the bank between 50% & 80%, you have 45 usable Ah's out of your 150Ah bank. At 100% state of charge you'll have 75 Ah's but if on the hook more than one night you may be constantly depleting your bank beyond a 50% depth of discharge unless you run the motor more or cut some energy use..
Is your alt a 30A unit? If so it won't put out 30A for very long. Once it gets hot you'll be lucky to get 20-24A out of it.
Here's what usable capacity looks like. When cruising you are usually cycling between 50% and 80% SOC or 30% of the banks capacity. When starting out with a full bank you'd have 50% of the total capacity to use.
That will work if you start from 100% SOC and only do one night. If you go more than one night your cycling between 50% & 80%. The last 15-20% takes many hours, like ten+, to get the bank back to full because of acceptance tapering.
If you add a battery monitor you may likely find that if you are using less or more than your energy budget. I often find customers have estimated in excess of 25% or more variance, sometimes in favor of the batteries, sometimes not...
Using the "cruisers rule", cycling the bank between 50% & 80%, you have 45 usable Ah's out of your 150Ah bank. At 100% state of charge you'll have 75 Ah's but if on the hook more than one night you may be constantly depleting your bank beyond a 50% depth of discharge unless you run the motor more or cut some energy use..
Is your alt a 30A unit? If so it won't put out 30A for very long. Once it gets hot you'll be lucky to get 20-24A out of it.
Here's what usable capacity looks like. When cruising you are usually cycling between 50% and 80% SOC or 30% of the banks capacity. When starting out with a full bank you'd have 50% of the total capacity to use.
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Update - wiring diagram with proposed location of solar panel / charger
Had a chance to diagram the DC system this weekend - see attached. I have included the previous / future charger location as well as the proposed solar panel and charger. Would appreciate feedback validating both how the boat is set up and how I plan to integrate the solar.
Thanks again as your help has been invaluable.
Rick
Had a chance to diagram the DC system this weekend - see attached. I have included the previous / future charger location as well as the proposed solar panel and charger. Would appreciate feedback validating both how the boat is set up and how I plan to integrate the solar.
Thanks again as your help has been invaluable.
Rick
Stu Jackson
C34IA Secretary
Rick, you really should get the alternator output (AO) off the C post of the 1-2-B switch. Run a separate wire from the AO to the house bank, fuse it, and if you choose add a simple on/off switch for when you're working on the alternator (I have a switch, uninstalled so far, so I simply remove the mega fuse when I do that). If you read some of the other electrical posts on this board, you find more wiring diagrams that Maine Sail contributed.
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Tom Metzger
Sustaining Partner
Loud rant!
Loud rant!
This has been discussed ad nauseum. Everybody has given their reasons for the way that they do it and it is now time for someone to pipe up with NEW ideas or reasons for doing it their way, or to let it drop.
On the other hand, maybe the people that feel strongly that their way is THE one correct way should buy the necessary equipment for those of us less fortunate or retired and living on a fixed income.
BTW, I'll need an echo charger, 200 amp fuses (2 ea), 175 amp switches (2 ea), 12 ft of red #1/0 (tinned SAE is OK), and $50 for miscellaneous wire, terminals, etc. I'd say about $425 delivered from Defender without getting fancy. I could use a little more so I could buy the recommended tools.
Loud rant!
This has been discussed ad nauseum. Everybody has given their reasons for the way that they do it and it is now time for someone to pipe up with NEW ideas or reasons for doing it their way, or to let it drop.
On the other hand, maybe the people that feel strongly that their way is THE one correct way should buy the necessary equipment for those of us less fortunate or retired and living on a fixed income.
BTW, I'll need an echo charger, 200 amp fuses (2 ea), 175 amp switches (2 ea), 12 ft of red #1/0 (tinned SAE is OK), and $50 for miscellaneous wire, terminals, etc. I'd say about $425 delivered from Defender without getting fancy. I could use a little more so I could buy the recommended tools.
Stu Jackson
C34IA Secretary
I sincerely apologize for both repeating myself and suggesting a basic safety issue for folks who don't choose to blow their alternator diodes. And you don't need an echo charger, either. JUst top off the reserve bank when you get back to shorepower.
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Maine Sail
Member III
Stu,
It is not a "necessary need" for every boater to get the AO off the starter post. I have many customers who have never blown diodes and whom are perfectly comfortable with that set up but many of them sail off a dock and use only the house bank, so the switch is only used as an ON/OFF which certainly reduces the odds.
If I had to put a number on it I would guess that at least 75-80% of the boats I work on, even very expensive ones, the customers have no clue that passing through OFF with the motor running will blow the alternator. While Ericson put it right on the panel, not to do that, most builders did not.
I fixed a Mainship 34 the other day that had a mess of switches, a horrible, unlabeled set up. The owner had blown the diodes by inadvertently flipping off the engine switch rather than the generator switch. This system was not at all KISS. It happens.
On many other boats the switches are not where they are on an Ericson. On many Ericson's the switch is right in the DC panel so it is very easy to not pass through OFF just as it is on many Catalina's with the switch in the panel.. Kind of hard to mess it up when you are looking directly at it.
On some boats I take advantage of the AFD (alternator field disconnect) on the battery switch that allows you to leave the AO on the starter post but breaks the field a few milliseconds before the load. Many owners don't even know their switch had this capability, not all do though. Of course in order to use the AFD you need a regulator that allows you to interrupt the field in order to use this feature.
Lots of boats have inaccessible switches that you are upside down and backwards to switch. Of course none of these locations would meet current ABYC standards but it is what it is and most owners don't want to incur the expense to move the switch and associated cable and fill the hole left by the switch.
I have one customer who has it behind him on the engine bay bulkhead when he is sitting at the nav desk. When he flips it standing by the companionway ladder he is fine but twice now he's tried to flip to the second bank while sitting facing forward and turned the switch the wrong way and went through OFF instead of BOTH. It is one of the Perko switches with the triangular knob that is tough to tell the position of when "blind" to it. The Guest switches use a "pointer" that can easily be felt if switching blind.
This is a smart guy, actually an engineer, and he insisted it would never happen again once I explained what had happened, even after a good HEF discussion. We ultimately decided not to install an ACR or Echo and move the AO. With two diode repairs he's now exceeded the cost of the Echo or ACR upgrade. It is now moved and he has an ACR. His issue was the switch location and the multiple body positions one could be in while switching it. This is not uncommon. With their quarter berth always loaded with gear there was really no easy way to get in there and physically look at it while switching so it was almost always blind.
On a race boat I work on they toasted the alternator this summer on an off shore race when the skipper asked a crew member to flip it to BOTH to charge both of the banks. This boat has very small banks to keep weight down. The switch is also in the engine bay to keep wire runs short and light and it was night time. Owner even said "don't go through OFF".. Crew member got a ration of sh&t for the remainder of the race and will probably not live that one down...
I had customers who were still cruising well into their 80's. They had done a circumnavigation in the early 80's and were not "inexperienced" sailors. Yet when into their 80's, combined with a bad switch location on their last boat, they too fried the diodes..
I am picking up an 80 amp Yanmar alt later today after having the diodes replaced, brushes and bearings too while we were in there. This owner knew nothing about "passing through OFF"... He asked what can be done as he does not want it to happen again. He decided to go with an ACR. I of course offered him either option, leave it where it is and discuss how and why it happens, or prevent it from ever happening again. He chose the latter..
While it happens, it is still not a 100% necessary thing that every boater "must do"..... If folks are comfortable with it then it is perfectly fine to leave it. I left it on the starter post on our C-36....
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Stu Jackson
C34IA Secretary
Main Sail, I agree, the skipper has to know what he's doing with whatever he has on his boat.
My only "recurring" question is:
WHY RISK IT?
I asked Jim Moe, a C34 owner and a professional electrical expert, the following question, with his reply:
Jim
Re alternators and regulators. I've always been under the impression that if the 1-2-B switch was turned off when the alternator output was wired through the C post of the switch that the diodes would fry. I also thought that if the regulator was turned off no damage would occur since the alternator output is still connected, just that the field isn't getting excited for output. In reading this thread, Jeff Tancock, another C34 owner, reported to me that he had OEM alternator output to the C post, his guests turned off the switch, but the alternator survived.
Stu
**********************************
Jim's reply:
Generally speaking the determining factor is just how hard the alternator is pumping at that moment. If it isn't working too hard the magnetic flux in the rotor isn't so great that you get a huge voltage pulse which back biases the diodes to the point they fail. If it is, the flux may be so great that even though the regulator says "cut back, the voltage is too high" there's enough residual flux to cause enough voltage to kill the diodes. Thus it's the luck of the draw.
Some of the later alternators have suppressors which limit the voltage spike which occurs under these adverse conditions and some use avalanche breakdown diodes (which are somewhat pricier) that are more or less self protecting. There's a possibility that what he has as well.
So far as the regulator being disconnected, you're quite right.
Jim
My only "recurring" question is:
WHY RISK IT?
I asked Jim Moe, a C34 owner and a professional electrical expert, the following question, with his reply:
Jim
Re alternators and regulators. I've always been under the impression that if the 1-2-B switch was turned off when the alternator output was wired through the C post of the switch that the diodes would fry. I also thought that if the regulator was turned off no damage would occur since the alternator output is still connected, just that the field isn't getting excited for output. In reading this thread, Jeff Tancock, another C34 owner, reported to me that he had OEM alternator output to the C post, his guests turned off the switch, but the alternator survived.
Stu
**********************************
Jim's reply:
Generally speaking the determining factor is just how hard the alternator is pumping at that moment. If it isn't working too hard the magnetic flux in the rotor isn't so great that you get a huge voltage pulse which back biases the diodes to the point they fail. If it is, the flux may be so great that even though the regulator says "cut back, the voltage is too high" there's enough residual flux to cause enough voltage to kill the diodes. Thus it's the luck of the draw.
Some of the later alternators have suppressors which limit the voltage spike which occurs under these adverse conditions and some use avalanche breakdown diodes (which are somewhat pricier) that are more or less self protecting. There's a possibility that what he has as well.
So far as the regulator being disconnected, you're quite right.
Jim
Maine Sail
Member III
I don't know why some do, perhaps because they are not aware if it or because they've gone 30 years without blowing the diodes and don't feel the urgency to move the alt off the starter post or because of the added expense or lack of skill or tools required to do the job.
Why do people feel safe with 30 year old standing rigging, or leaking seacocks, or rotted bulkheads, or crevice corroded chain plates, cracked and rotted below waterline hoses, cheap perforated hose clamps, no battery fuses or any of the myriad of other things I see that could be done safer...? Probably because they've yet to have been bitten by these things...
I am in a different situation than most boaters who have an n=1 experience. I work on many boats, from Hunter & Bayliner to Halberg-Rassy and Hargrave, so my "n" is significantly larger to draw experience from. Even with this experience and sharing examples of dangers and real world examples with customers they still sometimes choose to not do something I suggest to them would be wise. Not a problem, it's their boat...
Case in point; I installed a Harken furler for a customer and the angle to the halyard was incorrect due to the nature of the rig. The furler needed a halyard restrainer. The owner decided not to do it because the mast had been recently painted with Awlgrip. She explained how she had never had an issue with any boat concerning halyard wrap, so despite my clear and concise explanation of exactly what would happen, she decided against it. Long story short in July I was up the spar drilling and tapping the halyard restrainer at a much larger expense than if we had done it when the spar was down. She still didn't care, expense was not an issue, and was happy she had tried it her way. I was happy to get the work...
She just didn't know what she didn't know but was still very comfortable with her original decision.Jim is right the diodes don't always fail, and sometimes you get lucky, but this is usually when you have little if any load on the alt. The problem is that very often folks fire up the motor at 50% SOC or less, after a night or two on the hook, and then a few minutes later think to bring on the reserve bank. This is when the diodes will usually blow if they inadvertently pass through OFF. They don't all always blow at the same time either. I have seen a fair number of alts with 1/3rd output. For me voltage drop between the alt and batteries is why I prefer it. I measure many alts at 14.4-14.6 and the bank significantly lower and the banks are simply getting undercharged. Simply sensing the battery fixes this without expensive battery cable upgrades..
As of yet I have not seen any marine alternators like Hitachi, Prestolite, Balmar, Electromaax etc., with avalanche diodes built in but many of the newer automotive units meeting EU standards do. Even Balmar's still don't have avalanche diodes them.
Personally, I'd rather see folks with proper over current protection in place first and then tackle other nuisance issues, but that is not going to happen anytime soon as about 85% of the boats out there have no fuses on any of the banks. Our yacht club lost a boat last summer due to lack of bank fusing, so this one hits closer to home than where the alt goes.....