Solar panel battery charging

[gordd]

Hello everyone . It been while since posted here and have a question . I have two batteries in my f25 Trojan and am considering solar panels for charging them when away or on water for cpl days . Does anyone have that set up or know how many watts panels would be needed for something like that . I see panels can range from 20 - 100 and 100 plus watts .

[prowlersfish]

That would depend on how much you would be pulling from the batteries . Just to maintain them won't take much , but on the hook when you start pulling power lights , radio tv pumps , inverter, fridge it all adds up . Some sail boaters I know run 400-600 watts of panels cruising they monitor the power used to the power charged using a meter that tracks it .

[gordd]

Thank you Prowlersfish . would be more for trickle charge . like lets say over night lights perhaps radio , computer for little bit . I imagine 100-150 watts would be ok for something like that . I you tubed cpl ideas but if anyone has a Trojan set up what they use would be even better

[prowlersfish]

That should be fine , but when your using the most power probably will be at night when there is no sun . This is really no big deal as you have 2 batteries .What you need to do is just run your house stuff off 1 battery leaving the other charged battery to start the engine . Honestly it sounds like you will have a very lite load anyway so I don't think you will any issues with the house battery going dead even on the hook for a few days .The Pannel will recharge it during the day . Your biggest draw will be the computer and I assume a small inverter to run it .


You can limit your power draw a lot by turning off the inverter when not being used and changing all your lights to LED bulbs . They have gotten so much better and cheaper and draw very little power .

As far as keeping the engine battery topped up when in the slip ,a on board charger would be great if you have shore power . if not maybe a small panel just for that battery . Like LEDs they have gotten better and cheaper .

FWIW For years I had gotten by on in the slip and over night trips with no way to charge the batteries and never had a issue , other then a computer I had the same loads no shore power on the boat at all sitting in the slip . We cruised a lot on that boat that way . Until the boss said we need A/C on hot nights . So shore power was added and A/C ( we stayed a marinas a lot ) She was happy and life was better LOL. This was also a 25 footer ( not Trojan)

I guess what my point is you could get by with no panels unless your out for days . But adding them sure won't hurt and will give you peace of mind and that's always a good thing .

[prowlersfish]

You may find this help full ( or not )

http://www.boatus.com/boattech/articles ... ystems.asp

[gordd]

Thx again Prowlersfish . If summer ends up being like last one around here doubt will have to worry about air-conditioning , so basically just your regular every day stuff like coffe maker , fridge , radio maybe a hot plate . when out and away from shore power. Think may do each battery separate with 100 or 150 watt panell, one is deep cycle the other crank so should be ok. They come down in price lot even the flexible ones .

[canuckkb]

I use a 50 watt on my 26' Not a Trojan. We go away for a couple week long trips a year. In the fall when all we are running is a radio and few lights, it keeps up fine. In the summer when the fridge is running half of the time, plus the radio and a few lights, it is a little underpowered. However, we usually move around everyday so the engine does the charging.
The only caution that I have is that I have been told that the photo cells on the cheaper panels are in series. If a fly were to land on it, the shadow would shut off the cell and break the series. Therefore no power produced until the fly takes off. I do not know if that is true, but I always take some glass cleaner with me and clean it often.
One of the things that I do to save power is use a solar powered light for an anchor light.

[prowlersfish]

Thx again Prowlersfish . If summer ends up being like last one around here doubt will have to worry about air-conditioning , so basically just your regular every day stuff like coffe maker , fridge , radio maybe a hot plate . when out and away from shore power. Think may do each battery separate with 100 or 150 watt panell, one is deep cycle the other crank so should be ok. They come down in price lot even the flexible ones .

You added some hi power draw stuff to the mix "coffe maker , fridge , radio maybe a hot plate "

[Big D]

....You added some hi power draw stuff to the mix "coffe maker , fridge , radio maybe a hot plate "

+1
It's going to take a lot more than you're thinking if you plan on using a coffee maker or a hot plate. Those will draw a lot of power. You'll need a large battery bank and I wouldn't use an inverter that would put out anything less than about 1750 watts.

[captainmaniac]

One of the things that I do to save power is use a solar powered light for an anchor light.

Hope you can guarantee that the light stays on, and is bright enough, all night long, every night... on solar power. Your life depends on it. I have seen too many solar powered lights shut down early because of a prior cloudy day to trust them for something so important.

[gordd]

Solar panels would be mostly for trickle charge tho Big D. Like cunuckkb said suppose can always start up engine for full charge every once in while when staying out on water for cpl days . I just don't wanna turn that key and hear click click or nothing . I will see what my electrician would suggest as well .. have to get him in anyways to do cpl things before launch and he may have some options

[Big D]

What I was referring to was you saying that you were going to use high amperage draw devices with having mentioned earlier that you had only one deep cycle battery. Hope it's at least an HD 8D battery! A 15 amp coffee maker or hot plate through an inverter will draw a lot of power, and if you take the battery down too low too many times, you will kill it much quicker. How long it takes to recharge simply depends on your charging system's output, be it engines, house charger or solar power.

[canuckkb]

One of the things that I do to save power is use a solar powered light for an anchor light.

Hope you can guarantee that the light stays on, and is bright enough, all night long, every night... on solar power. Your life depends on it. I have seen too many solar powered lights shut down early because of a prior cloudy day to trust them for something so important.

I can guarantee it. I went to CT and read the boxes for the different lights. I bought the extra bright lights. They have a brightness selection setting choice which is good for 8 or 12 hours. I bought a box or 4 and tried them out in the back yard and found that they lasted the hours despite the previous day being sunny or cloudy and rainy. At anchor, I found that the low setting (12 hr) was brighter then any other anchor light in the anchorage. Because I bought four, that allowed me to bring an extra battery or two so that I can swap them out if I felt like the battery was getting week. If all else fails, I still have the boat anchor light. I am an early riser and the light is always on when I wake up.

[comodave]

Are these solar powered anchor lights certified to meet the CG standards? Even changing the stock bulbs in navigation lights to LED bulbs can be problematic as to legal liability. Navigation lights are certified to meet the standards when they have the stock bulb in them. Changing to a different bulb may cause the light to not meet the standards. If these anchor lights are not certified, you could be putting your family at risk of a collision due to not being seen. Even if everyone survives a collision, you may be putting yourself at risk in a law suit if you do not have correct navigation lights (an anchor light is a navigation light). If there is a collision the various insurance companies will hire investigators to determine who is at fault. If the collision happens at night, they will inspect the navigation lights to make sure they are in compliance. Unfortunately that is the world we live in today, you must plan ahead in order to mitigate your liability. I would not change anything in respect to nav lights, except for changing out the whole light with another approved light. In the event of a collision, would you want the investigator to read these posts about using possible unapproved anchor lights? It is just not worth it to save a little battery power. Get a larger battery or add another battery to power an approved anchor light. Now all this is on the assumption that the light you are referring to is not approved, if it is an approved light, please disregard this post.

[canuckkb]

Maybe it is more a question of common sense. I have a light that is far brighter than incandescent, easily last the time duration that is required, and I am anchored in charted anchorages or I am in such a tight cove, and so close to shore, that I run a line to a tree. I feel very confident that nothing will run into me in my entire life time. The only thing that I worried about running into me is beaver.
In short, I am not changing what I am doing and not talking about this any more, as I am sure there others that will want to prove their superior intelligence.