Power management aboard

[Rory McDougall]

Hey folks,

I think it would be a good topic if we all shared what electrical charging and management systems works well for you and your needs aboard. Obviously it is all down to replacing the amperage juice we like to consume on a daily basis. On Cookie, we have mainly shunned electrical technology over the years but during last years adventure I wanted to keep in touch with family and any followers of the Jester Challenge. Here's what worked really well for us:

An 80Ahr AGM battery that feeds a 10watt masthead light, cabin lights, 12V outlet sockets and a NASA AIS radar display. I worked out that running the AIS display, 2x handheld GPS and charging satphone, VHF periodically we used approx. 0.5Amps - so about 12 Amps per day.

To charge up again we used an Aquair 100 water towed generator. It worked really well and as long as we were doing about 5kts plus it would top up the battery in about 4 hours after every 3 day period. Of course if I used cabin lights a lot or the masthead light I would be charging much more. The Aquair from Ampair did slow us down about 1kt when towing, but hey Cookie is only a 500kg lightweight - I expected some sort of performance loss when towing. In fact one or two of the other monohull Jester sailors towed their water chargers 100% of the time to keep on top of radar set demands, autopilots etc. So for larger Wharrams, I doubt there would be any hull speed loss. Ampair state a load of pull from the towed propeller of around 40lbs at 6kts and that seems about right from what I observed on Cookie.

So although it was some manual work to deploy and retrieve the tow to charge each time, It meant that as long as we were not becalmed I had control of my green charging ability. For North Atlantic I think it was the perfect solution for us rather than solar panel and the lack of sun we had.

If I had a larger Wharram and wanted to go cruising without fossil fuels, I would probably have a combo of solar, wind charger and water towed charger.

What feedback do others have that works well for them? Equipment specific would be helpful.

Cheers, Rory & Cookie

 

[Ann and Neville Clement]

PART ONE

Peace (Tiki 46)has four separate systems.  The house system has 4 100 amp hour batteries charged by 4 80 watt solar panels and this works well for our style of cruising which is coastal and some offshore.  We will be glad when the mast head light is LED.  When overnight sailing, we still need to add more electrics with the Honda generator, but LEDs will take care of that.  Our cabin lights are now LED from the hardware store and they were cheap and look good and NEv put them up himself.  WE use an autohelm a lot, GPS has a chart plotter, and I like to leave the depth sounder on because whales and submarines can hear it and avoid us.  On sunny days in harbor, I use a laptop plugged in to the 12 volt system asissted by an EnGenius antenna enhancer, and we sail with a hand held VHF on channel 16 and recharged on the 12 volt system.   Our radio for news and music operates on rechargable batteries recharged on the 12 volt system too.  All that works well.

    Looks like this will have to be a four part note. 

    

[Ann and Neville Clement]

PART TWO

     Our electric windlass has its own battery and we admit that it is only recharged by the honda generator.  It is very powerful and we love it.  Nev starts the Honda, then gets the anchor ready to lower or lift at the press of a button which sure makes it easy on an old man's back.

[Ann and Neville Clement]

PART THREE

     The engines have their own starter batteries which they recharge themselves.  Another configuration is for us to hook up the engines to the house batteries and let the engines recharge their own batteries as well as the house when they are running.  Currently he has them on the house batteries and seems pleased but we had them on their own for years.

[Ann and Neville Clement]

PART FOUR

     The freezer has its own 100 amp hour battery which has two 80 watt solar panels and is all in balance.  We freeze a gel pack and take it down to the galley to a cool box he built in down there and each day we swap over one from the freezer to one from the cool box.  This keeps stuff cool and handy for me in the galley and the freezer is at -8C mostly.  On cloudy days we may need to use the Honda to assist it. 

 

KEEPING TRACK

    To keep track of all these systems, we have some regulators, some cheapie meters with "twinkie lights" which are easy for me to read - if the green light is on, then it is all ok".  The main bank of house solar panels has a fancier meter with digital readout. 

 

Hope this all helps.  Sorry for the four part answer but the computer cannot manage longer reply here for some reason. 

[Rory McDougall]

Thanks for all your details Ann,

Seems everyone will have different needs for electrical power aboard - ain't that the beauty of our individualist boating lifestyles!

I have fitted 2 x Air Breeze wind generators to a Norseman cat in Belize and then 2 x 100watt solar panels as the owner didn't want to run the genset at all if poss. I was impressed, being in the tropics it did keep up with most of the basic on board fridge, lighting, electronics needs. There is definitely a sense of cashing in from the natural energy around us when you hear the hum of the wind chargers and the battery voltage hovering at 13.8!!

Does anyone have a good source of non-marine marketed solar panels that work just as well but are a fraction of the cost??

[Robert Sheridan]

Just finishing of our upgrade.  Originally we had an independant 120 Ah battery in each hull each of which was charged of 2 solar panels in the deck which could be walked on (can't remember the output of the top of my head but they are about 3 ft long and about a foot wide) which did a reasonable job of keeping the batteries charged, but we had problems running the autopilot though it could be that it was because the battery was old.

We are about to go off extended cruising and have replaced the open cockpit with a pod so we have added the larger of the two Forgen generators, which can deliver 3 amps and has no blades to come off.  I have wired the Forgen so that it charges both batteries (I plan to add a switch later so that I can isolate the batteries in case one fails) and have wired the pod so that it can get power off either or both batteries.

We are about to replace one of our masthead lights with a LED (hopefully the tricolour) and have LEDs in the pod.  Other than lighting we are running 2 GPS, AIS, active radar reflector, NAVTEX, VHF and on occaisions a autopilot, laptop and a charger for torch batteries etc.

We realise that the Forgen will not work well going downwind, but it will enable us to use the laptop when we are moored.

The solar panels have regulators which give an indication of the charge level of the battery they are charging, unfortunately they need to be sited near the battery as they need to know its tempreature and this means getting in to a locker to see the state of the battery; therefore, I usually check the battery with a volt meter stuck into a 2 pin socket wired directly to the battery and then switching on everything attached to the battery to see how it behaves under load.

This new set up will be tried out for real in June/July as we have a delayed start to our trip.

Robert

[boatsmith]

The best prices that I have found so far for solar panels is Sun Electronics in Miami. They have a large selection of brands and sizes.

[Rory McDougall]

Hey Robert - will be interested to hear how the Forgen works and what output you get. It seems a much safer way to go for small boats than to have a high tubular frame with deadly windmill blades ready to take an arm or head off. The Air breeze I fitted gave me a good cut on one finger just by spinning the blades by hand in no wind!!!

I did just find a supplier of 80watt panels on ebay selling now for 155 pounds!! I wonder what the catch is??

Obviously the achilles heel of all electrical systems is resistance - and that mainly comes from connections and terminals as long as wire size is rated correctly. I advise using heat shrink connectors if you can afford them, otherwise I use sikaflex or 5200 forced into the open ends of the connectors once crimped to keep them as watertight as poss. A good spray with corrosion inhibitor afterwards works well to give your electrics a waterproof barrier. Cookie is a pretty good electrical test bed!!!

Cheers, Rory.

[andy solywoda]

Harbor Freight sells a 75watt kit that includes 3 15W panels, a mounting frame, charge controller, some adapter plugs, and 2 12volt CCF lights.  The CCF bulbs can be uscrewed and used in any incandescent 120V socket, of course wiring the fixture into 12VDC.  The charge controller on the units I bought isn't very good, just a shunt regulator.  The new kits are using a different charge controller, but I don't know if it is any good.  The 3 panels together take up about a 3' square area.  I made hatch turtles and installed 4 kits, one over each hatch.  Because we don't normally sit on hatches, the area taken up by the panels isn't a problem.  When walking on the cabin tops, for line handling for instance, the panels are an obstacle and would probably break if stepped on.  They are rated at 75W at their optimum "power point", which is around 17 volts.  The open circuit voltage is around 22 volts.  Hooking them up directly to 12 volt system drops the power rating to around 55-60 watts.  The lost power can be regained by using a MMP charge controller.  The price of the charge controller equals the price of an additional solar kit.   I'm using a Sunsei charge controller which is not MMP, but does a nice job of equalizing the batteries.  I'm thinking of adding a hard dodger of solar panels, but that will be in the future.  I'm experimenting with an inexpensive wind generator (Scorpion) which is a kit that is unpainted and has 6 blades.  So far it has been whirring back on the stern for about 6 months with no blade problems.  It is rated at 600W at some higher wind speed.  Maybe 30 knots.  A neighbor boat has lost his blades twice, once when a bird blundered into them and another when a stay came loose and the wind blew it back into the blades.

[andy solywoda]

I was at the store today to get a few things and they are selling the solar panel kits at $179.99, right around the 2-3 dollar/watt going rate.

[Ganz Daniel]

Our Tiki 38 has 4 batteries each 80 amps. we feed them with 4 solarpanels, each one 100watt peak. We have so much power that I sold my windcharger and changed the leds in the cabins back to consuming halogens because the light is much warmer. We have fridge, satphone. two labtops,( and they are running a lot with 3 kids on board...)radio, gps etc, even the wheelsteering works for many ours.Since our boat is in the water (2009) we never been on  shorepower  or on a generator. So here some important points on solarpanels:

If you want go with solarpanels do not buy cheap panels, you will be dissapointed, do not use the flat ones they are not yet as powerful as they could be.

The best ones are monocristalline they have black colour ( they come from space tecnologie) and they have a lot better output then the polycristalline ones.(blue color)

The diameter of the cables are important! As thinner they are as more you loose from the panels.

The isolation of the fridge is also very important! As thicker as better, with a bad isolation you loose a lot of energy! In the small hulls of a wharram not an easy thing to do, I recomment vacuum isolation panels, they are expensive but very good. In a 20mm panel you have the same isolation like 200mm normal isolation panel. Everything works very well simple and efficent!

[Rory McDougall]

Thanks Ganz for your helpful suggestions. Where are you doing your cruising??

Cheers

rory