New C22 owner here. Looking to setup my factory electrical system with a trickle charger and solar panel. Also like to install a battery switch. Any helpful suggestions/resources etc are appreciated.
Solar panel/battery charger suggestions 1986 C22
- Thread starter Fuji242
- Start date
The really low wattage panels, i.e., under 50 watts won't really charge a battery they will maintain the battery at charged level.
A 50w panel with a good controller will provide about 4 amps of charging current, just barely enough to recharge a Group 24 FLA battery over the course of a week.
The better answer depends on what you kind of electrical devices you have and how much electricity you use. Without that information, it is hard to give any more than a very general answer.
My notes start here. My Rogue MPPT controller isn't manufactured any longer; if I were starting over, I'd definitely go with a Victron MPPT controller - versatile, well made, and reasonably priced.
Since my original notes, I switched to securing our panels to the bimini with N52 rare earth magnets. ~1.5" magnets on the bimini (in pairs, under and over), as removable mount points. And 3/4" sticky-backed magnets on the panels (smaller ones on the panels, so that removing the panels doesn't pull the upper "mounting" magnets off the bimini and drop the lower ones somewhere unpredictable).
Why? Sticky-backed velcro never stuck to the bimini very well. And I didn't really want to sew velcro or other fasteners through the fabric and create a bunch of leak points. YMMV. Some magnet sizes are available at Amazon or eBay, or you can find anything you like at KJMagnetics.
Since my original notes, I switched to securing our panels to the bimini with N52 rare earth magnets. ~1.5" magnets on the bimini (in pairs, under and over), as removable mount points. And 3/4" sticky-backed magnets on the panels (smaller ones on the panels, so that removing the panels doesn't pull the upper "mounting" magnets off the bimini and drop the lower ones somewhere unpredictable).
Why? Sticky-backed velcro never stuck to the bimini very well. And I didn't really want to sew velcro or other fasteners through the fabric and create a bunch of leak points. YMMV. Some magnet sizes are available at Amazon or eBay, or you can find anything you like at KJMagnetics.
Waffle House has been on the hard for going on a year and a half +/-. The battery just sat in the boat unused so in the late fall, I got a 35 Watt Battery Tender solar panel and controller:
I just laid the panel on the starboard side of the cockpit, placed the controller in the coaming and using the quick disconnect plug which was already on the boat, I was good to go:
It took a few winter months for the controller to switch from charging to "charged" but this weekend I took the five year old Interstate group 27 deep cycle marine battery in for a check up and it tested as good as new. Will 35 Watts keep the battery charged once Waffle House hits the water? Time will tell but considering that everything has been upgraded to LEDs it should have no problem keeping up with the demand.
George
I just laid the panel on the starboard side of the cockpit, placed the controller in the coaming and using the quick disconnect plug which was already on the boat, I was good to go:
It took a few winter months for the controller to switch from charging to "charged" but this weekend I took the five year old Interstate group 27 deep cycle marine battery in for a check up and it tested as good as new. Will 35 Watts keep the battery charged once Waffle House hits the water? Time will tell but considering that everything has been upgraded to LEDs it should have no problem keeping up with the demand.
George
Am planning on starting out small and see how it goes. Just average list of accessories for coastal cruises, nothing crazy (Ipad & IPhones , Bluetooth speaker obviously). Would like to be able to spend 5 day’s on it comfortably without having access to a chord. I haven’t had a chance to do much research yet but am mechanically inclined and will do everything myself. Just looking for a good place to start and build from others experiences.
On average a decent quality solar panel will produce about 3 times its nominal rating in power per day. Bright sunny days in the summer will be a little higher, gray overcast rainy days, much lower. A 50 watt panel will produce about 150 watt hours (or 12.5 amp hours), a 100 watt panel will produce about 300 watts (25 ah).
Calculate the energy you'll consume charging the phone, lights, etc. This will tell you how much power you need to generate.
Generally, Group 24 batteries have about a 70 ah capacity with only 35 ah of useable capacity when brand new.
Now it is just a numbers game, can you produce and store enough electricity for your needs? There are 2 options, vary the usage or increase charging. Just to make things more exciting there is 15-20% inefficiency when charging lead acid batteries, take out 10 ah and you need to put back 12.
Great information, thank you! Do you have a website you can recommend for learning/calculating and were is great place to shop Solar/Marine electrical systems/supplies?
Now this is a tough question. Most of what is written online is for larger systems for cruising boats with high output alternators and larger solar arrays. The principals are the same, just the scaling is different for your application.
MarineHowTo.com is a great source of information on electrical systems. Rod, aka MaineSail also has an Amazon store, he will not list knock offs or cheap products, so if it is in his store it will be of decent quality. There is a link on his website to his store and to Bay Marine for items he doesn't have on the Amazon site. One of the things you want to understand is battery chemistry and charging. There are several good articles on Rod's site on this.
Since you will be building a smaller system, look for packages at Defender, West, and other known reputable sellers. On the Chesapeake, you might take a look at what Fawcett's in Annapolis is selling and also PKYSinc.com is selling both reputable dealers.
Calculating usage is an educated guessing game. Take the current draw for a device, estimate how long you will use it each day, and multiply the time by the draw. There are spreadsheets online that can do the math. Devices like phones, computers and such, you can find the capacity of the battery in watts and divide that by 12 to get the number of amphours it will take to recharge the device.
In this endeavor, Duck-Duck-Go (alternative to Google) is your friend. Be wary of sources that seem out of the mainstream.
on everything @dlochner said.Copying / adapting from some of my previous notes:
- Start by reading through @Maine Sail's articles at MarineHowTo.com. He recommends some good quality crimp tools at reasonable prices.
- If you go no further in your reading, remember: fuses and breakers are there to protect the wire and prevent fires.
- I believe ABYC calls for a battery to be fused within 7" of the positive terminal - the easiest way is with a terminal block fuse block right on the battery.
- The solar panel side of your charge controller is much more flexible - the panel output current is limited (e.g. ~8A for a 100w panel). So with any reasonable wire size, you don't need to fuse the wires from the panel to the controller. The battery -> controller wiring must be fused.
- Blue Sea Systems is top-notch (bus bars, breaker panels, etc.)
- Custom Cable USA (formerly GenuineDealz) carries high-quality wire, heat-shrink connectors, etc. Reasonably priced, and they ship quickly. Stock up on crimp connectors, so you have the right parts on hand. Just buy the 25-packs of all the common sizes.
- They will make custom cables too - e.g., if you need battery cables and don't want to spring for battery-lug crimpers.
Just an FYI, you have to produce power for your usage plus battery self discharge.
So how much is lead acid battery self discharge? These guys Battery 101 Three Things Need Know Lead Acid Batteries | Northeast Battery Blog. say its 5 percent per month. If the battery capacity is 100 amp hours, that is 5 amp hours per month or 0.16 amp hours per day. Using the numbers previously given here (50W panel produces 12.5 AH per day), only 0.64 watts of solar is all that is needed to keep up with a 100ah battery daily self discharge. If you have two batteries, only 1.3 watts of the solar keeps up with self discharge. The rest you get to use.
My advice.. install a simple battery monitor when you add solar. This gives you net amp hours in/ out of the battery. I have done this with a trailerable sailboat with typical low power loads and have tried 10, 20, 30, 40 watt panels on one week trips. Im always watching energy in and out of the battery and found that 20 watt was threshold, 30 watts works fine and you will have some power to spare with 40 watts. This assumes you dont have any unusual high power demands such as a fridge or you are using a laptop for 5 hours each day.
You are likely to start a one week trip fully charged and dont need to finish a one week trip fully charged. Its just fine to be down by 30 amp hours at the end of the trip. These are trailerable boats, your not living on it full time.
So how much is lead acid battery self discharge? These guys Battery 101 Three Things Need Know Lead Acid Batteries | Northeast Battery Blog. say its 5 percent per month. If the battery capacity is 100 amp hours, that is 5 amp hours per month or 0.16 amp hours per day. Using the numbers previously given here (50W panel produces 12.5 AH per day), only 0.64 watts of solar is all that is needed to keep up with a 100ah battery daily self discharge. If you have two batteries, only 1.3 watts of the solar keeps up with self discharge. The rest you get to use.
My advice.. install a simple battery monitor when you add solar. This gives you net amp hours in/ out of the battery. I have done this with a trailerable sailboat with typical low power loads and have tried 10, 20, 30, 40 watt panels on one week trips. Im always watching energy in and out of the battery and found that 20 watt was threshold, 30 watts works fine and you will have some power to spare with 40 watts. This assumes you dont have any unusual high power demands such as a fridge or you are using a laptop for 5 hours each day.
You are likely to start a one week trip fully charged and dont need to finish a one week trip fully charged. Its just fine to be down by 30 amp hours at the end of the trip. These are trailerable boats, your not living on it full time.
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Great information!! I will check them out, thank you for your time!
Copying / adapting from some of my previous notes:
- Start by reading through @Maine Sail's articles at MarineHowTo.com. He recommends some good quality crimp tools at reasonable prices.
- If you go no further in your reading, remember: fuses and breakers are there to protect the wire and prevent fires.
- I believe ABYC calls for a battery to be fused within 7" of the positive terminal - the easiest way is with a terminal block fuse block right on the battery.
- The solar panel side of your charge controller is much more flexible - the panel output current is limited (e.g. ~8A for a 100w panel). So with any reasonable wire size, you don't need to fuse the wires from the panel to the controller. The battery -> controller wiring must be fused.
- Blue Sea Systems is top-notch (bus bars, breaker panels, etc.)
- Custom Cable USA(formerly GenuineDealz) carries high-quality wire, heat-shrink connectors, etc. Reasonably priced, and they ship quickly. Stock up on crimp connectors, so you have the right parts on hand. Just buy the 25-packs of all the common sizes.
- They will make custom cables too - e.g., if you need battery cables and don't want to spring for battery-lug crimpers.
I don't know if they are any better now, but I had a very disappointing experience with a battery monitor and solar. You see, the monitor, a Victron BMV-600, couldn't tell the difference between the sun going down and the batteries coming to full charge. As the sun went down the current would drop off gradually, and the Victron algorithm took this to mean the batteries were coming to full charge. When it reached about 3% of capacity it declared the batts full, and set the stored energy to 100%. And, this was usually not the case. So it was just about useless as a gauge of available capacity.
I wouldn't bother.
I have a Linklite that is probably near 15 years old now and I dont bother with the percent full display. I only look at amp hours, instantaneous amps and voltage. The percent full is only valid if you know the battery capacity which changes over time. Its the amp hour display that I find useful. For the OP,, this is an accumulation of current into and out of the battery. When I was on a week long trip with say the 20 watt panel, I would for example see the amp hour used increase at night but then tick back down during the day when there was sun and solar charging. Over the course of a few days, I may see the amp hour used tick upwards but even if I had a deficit of 40 amp hours near the end of the trip, I would not worry because I know how much battery I had plus I watch battery voltage.
I think it also helps you understand better how much energy you are using. You can take the other approach and just add a lot of panel and only need to know that your in float by afternoon but not everyone wants that big of a panel on a 22 ft trailerable sailboat.
If actual battery capacity/ state of charge is important (more like the gas gauge on an auto), a simple battery monitor wont be all that useful.
I think it also helps you understand better how much energy you are using. You can take the other approach and just add a lot of panel and only need to know that your in float by afternoon but not everyone wants that big of a panel on a 22 ft trailerable sailboat.
If actual battery capacity/ state of charge is important (more like the gas gauge on an auto), a simple battery monitor wont be all that useful.
Nice! It looks like you are using roughly the same panel mounting arrangement we are, but with bigger panels! Any difficulty keeping those 50W panels in the up position?