solar panel information for charging deep cycle battery for iceshack

[JJK]

I was thinking on running a solar panel to keep my battery charged but how many watts do you need to actually start to charge the battery? Dont want to buy a big one so would a 5,10,15,20 watt solar panel do this?

[Drifter_016]

All of those will put a charge into the battery, but the higher the wattage the faster it will charge. You will also need a charge controller (regulator) so you don't over charge and ruin your battery. A 30 watt panel will give you a charge rate of 2.5 amps or about the same as a trickle charger. A 100 watt panel will give you a charge rate of about 8.4 amps which will recharge a group 27 battery in about 6 hours. If you are only going to use it say on weekends a 20 to 30 watt panel should more than charge the battery during the week.

[JJK]

All of those will put a charge into the battery, but the higher the wattage the faster it will charge. You will also need a charge controller (regulator) so you don't over charge and ruin your battery. A 30 watt panel will give you a charge rate of 2.5 amps or about the same as a trickle charger. A 100 watt panel will give you a charge rate of about 8.4 amps which will recharge a group 27 battery in about 6 hours. If you are only going to use it say on weekends a 20 to 30 watt panel should more than charge the battery during the week.

Thank you and will this concept work in the summer like to charge a electric trolling motor while in use?

[Bailbuster]

Look on ebay for the panel that came with VW vans,I have one it will not over charge the battery ,works great.BB

[Drifter_016]

Thank you and will this concept work in the summer like to charge a electric trolling motor while in use?

Yes it should work, but you will need a 100 watt or better panel as the trolling motor will draw a lot of power. A smaller panel will not be able to keep up. Also it will need to be a 12 volt system, which limits you to about 55#'s of thrust or less.

[beeverfishing]

Thank you and will this concept work in the summer like to charge a electric trolling motor while in use?

Depends on how much you use the motor and the size of the motor.  If you plan to run it consistently, then No...after awhile your battery would discharge..  The size of panel you would need to run a trolling motor while keeping your batter fully charged would likely be larger then your boat.  If you were to only use the motor for an hour or so, The panel could possibly recharge your battery to a fully charged state, depending on the size of the panel, amount of sun, temperature..etc...

[beeverfishing]

Also concider that a 12 volt battery needs more then 12 volts to charge it.   Normally between 14 to 16 volts is applied to a battery from a charger /alternator.   A 30 watt solar panel will not give you 2.5 amps.  I believe most solar panels have a nominal voltage of 16 or 17 volts, Thus a 30 watt panel would only give you approximately 1.7 - 1.8 amps. and that is under perfect conditions.  
Correct me If I am wrong, I'm not an electrical engineer, but I believe this to be pretty accurate..

[Lifeguard]

You are correct, but a person can also buy a charge controller that has MPPT or maximum point power tracking I believe is what it stands for.  It changes the output voltage of the solar panels to match the charge voltage requirements of the batteries and actually increases the charge current because of it.  Do a little research on the net for MPPT solar charge controllers.  I have one for my cabin.

Here's a good read on how MPPT charge controllers work:

http://www.solar-electric.com/charge_controls/mppt.htm


And as far as trolling motors, you can use a panel to charge 24 volt strings or even 36 volt, if you buy the correct panels.  Not all panels are made to work on a 12 volt system.  But you would need a BIG panel to notice a difference on run time while you were running the trolling motor. 

Another thing to consider with the shanty system is that a discharged battery will freeze, and the temperature required to freeze a battery is related to how much charge is still in the battery.  Therefore if you are out fishing all weekend and have the battery drained fairly low, and you turn off the heat, lock the door, and leave to let the solar panels charge the battery over the week, there is a very good possibility that the battery will freeze before it charges, and the battery life will be seriously reduced.

[edfalc]

excellent article....very informative.....ive been thinking about incorporating a solar system into my next shack

[Wiener]

Here's a website where you can buy  solar or wind generators.

fishhousesupply.com

Hope this helps,

Wiener

Drifter,  Sounds like you know solar panels / charge rates.  You off Grid way up there?

[Drifter_016]

Here's a website where you can buy  solar or wind generators.

fishhousesupply.com

Hope this helps,

Wiener

Drifter,  Sounds like you know solar panels / charge rates.  You off Grid way up there?

Nah, I'm in town. 
My friends have cabins off grid that we like to hang out at and catch lakers though.   

[JJK]

Here's a website where you can buy  solar or wind generators.

fishhousesupply.com

Hope this helps,

Wiener

Drifter,  Sounds like you know solar panels / charge rates.  You off Grid way up there?

Great web site,thanks to all of you for your input

[Bailbuster]

A 30 watt panel is about 16X30 and cost is around $200 to $270, The VW panel is 3.5 watt and is 14. on ebay and will keep a battery charged.BB

[$ignmoney]

A buddy bought one from harbor freight for his camper and it works good for him. Good idea for a perm. shack.

[beeverfishing]

A 30 watt panel is about 16X30 and cost is around $200 to $270, The VW panel is 3.5 watt and is 14. on ebay and will keep a battery charged.BB

Yes,  3.5 watt panel will keep a battery charged.. ONCE it is already fully charged !!  At 3.5 watt that is at best 0.25 amps.  those are used for a maintenance charge, (charging during storage).  Once there is a load connected to the battery, that panel is pretty much useless.  A trolling motor can easily draw 25 amps.