Small solar panel/battery charger ... do they work?

[Krebber]

I run a 12-v system in my fish house and am wondering if it's worth the money to buy a solar panel/battery charger that I've seen advertised in Cabelas and at Northern Tool. My battery lasts 2 days or so...but I was thinking if these things work, they might make a nice supplement and I would not have to think too much about running lights/tv/cb/etc. Anyone have experience with them? Worth the money? Thanks for any help!

[Whoaru99]

Yes, they do work, but how well and is it right for you depends on how often you use your fishouse and your electrical demand.

Most solar panels amount to a trickle charge. So if you use your house for a day or two per week, the solar panel may keep the batteries fairly well charged. However, if you are at the house most every day then I don't believe the typical solar charger will keep up.

One can get multiple panels or higher output ones, but then the costs add up pretty quickly as compared to throwing the battery in the back of the pickup every other day.

Let's look at the math...

Assume your battery is 100 Amp-hours for sake of discussion. You say it lasts about two days therefore you are using about 50 Amp-hours per day.

One of the solar panels I looked at was 15 watts at full power. 15 watts / 13 - 15 volts equals about 1 Amp or just a bit more. So, it would take roughly 50 hours of good charging time to restore 1 days use in this example. Then you have to figure in how many hours of light per day there are in the winter months to get an idea of whether or not it fits your needs. Assume 10 hours sunlight per day (again for easy math) and you would need 5 days of charging for 1 day of use in this scenario. This all assumes the panel puts out full power for the entire time so it's a best-case scenaro.

[beer batter]

The angle of the sun through much of the winter is too low to do much with those solar panels. Not to mention the weeks we go through without seeing the sun through parts of winter. They'd work great charging batteries over the summer, just not so great over the winter.

[Surface Tension]

Whoaru99, summed it up very well. The solar charger won't extend your batteries life in two days fishing and won't fully charge your battery for the next weeks fishing either. You'll end up having to bring it home to charge it either way.

[BobT]

It's also important to consider that recent evidence suggests that for best performance and long life, batteries should be recharged as soon as possible after use. To let a battery set for extended periods of time at low charge is not always a good idea.

Bob

[dfv87]

Not to mention that on most lakes (IMO) if it aint nailed down and screwed in and crazy glued on it will get stolen. And if it cannot come off they will break it just for spite.

Boy I sound pretty negative I guess. Sorry you caught me on a frustrated morning.

[fivebucks]

I have the 15 watt one from Cabelas and use for my trolling motor batteries and I have found it does the job as long as there is a week between uses and the batteries aren't drained too far down. This is summer time use with alot more charging time than the winter though.

[Krebber]

Thanks to everyone for the advice. Yet another reason to buy a generator!

[nytelyter]

was at the state fair today and talked to the guys at the alternitive energy booth up by the ecology building (old tecnology building) and am now convinced that what i have posted about the wind powered generators is not the best thing to do. the guy i talked to about them said that they have to much vibration and are very annoying. which i thought was not a problem but he sells them and if he says so i can believe him. if you are to go with solar think big watts. between 150 to 200 watts and for a 200 watt set up think about $1000 and he also said that mounted on the south side of the house on the flat is the best as you get reflected sun off of the ice and snow as well as direct light. he also said he has three houses with solar and one actually has 600 watts of panels and they use a small microwave and lots of toys in it. now get this he does carry a small generator for those long sunless stints that we occasionally get. so if you are at the fair and want some great info on alternitive chargeing sources stop by their booth. ... paul

[Swimmer]

Great replys guys. I think nytlyter has the correct summary of solar potential. My experience has been positive. I have one 15W solar charger attached to the back of a boat seat and have gone a week in the "wilderness" without having to charge the one 12V deep cycle. THis is with light to moderate use of 55#PD trolling motor (with most hours given to charging only). Given that the batteries were topped up at the start and it was quite sunny that week, I was still somewhat amazed. That was 8 years ago and the panel is still putting out. Granted, the solar panel would be considerably more efficient in the Summer Months. If you can maybe put out 50W solar, and you only use it weekends, it just might do the job (not as noisy as generator either).

[PierBridge]

How much are the 15 watt solars at Cabella's.....

[nytelyter]

not sure about cabelas panels but i will tell ya that i paid about 170 per 15 watt panel on my house. and also that a 45 watt panel will run ya from 450-500 duckies. for one battery and only fishing on weekends i would go no less than 45 watt.

[Whoaru99]

The idea is great - use solar, but it seems like a pretty large outlay for a functional system compared to hauling the battery back and forth every couple days - IMO, of course.

[fivebucks]

I can't remember exactly what I paid but I think it was around $100-$150 plus I bought a solar controller for $30 to prevent overcharging.