Solar chargers

[tcallis]

I store my boat in storage lot near my lake without access to electrical. To help the keep the batteries charged, I'm contemplating a solar charger. I'm considering the following two:

http://www.amazon.com/Sunforce-50022-Battery-Trickle-Charger/dp/B0006JO0TC
http://www.amazon.com/Sunforce-50033-15-Watt-Solar-Charging/dp/B001RJOP5Y

Does anyone have any experience with either? Or any thoughts about using solar chargers like this in general.


Thanks, Tom

[MLA]

Tom,

Something like that will maintain a fully charged battery, providing there is enough sun, but it will not do well to recharge a depleted house battery if the boat is put back in storage after a long weekend with a lot of time spent playing the system while at anchor.

[tcallis]

MLA,
Thanks. I usually don't spend much time anchored discharging the batteries. I'm mostly concerned about the bilge pump discharging the battery, which has happened to me (though I might not even have this problem anymore with my new cover). I suppose every bit of extra charge helps.
Tom





Tom,

Something like that will maintain a fully charged battery, providing there is enough sun, but it will not do well to recharge a depleted house battery if the boat is put back in storage after a long weekend with a lot of time spent playing the system while at anchor.

[EarmarkMarine]

Tom,
A solar charger doesn't work at night and generates far less power when overcast or the sun is well off axis. So it may not be much of a restoration device.
But as a maintenance charger it's okay. However, you have got to have a sophisticated charging module that can profile the battery and correctly respond. Voltage and current limiting will be important. For example, you do not want to continuously apply a 5 amp current to a fully charged battery for any length of time.

David

[philwsailz]

These particular units are the pedestrian every-day-joe all-in-one box solution and are also sold out there as a COLEMAN brand solar panel also.

I have personal first-hand experience with similar and/or identical units. The first one is the 5W panel and is the smaller of the two. I have used that panel as a backup cranking battery maintainer on a vintage Chris Craft powerboat. Its output is so small that it is generally suggested a charge controller is not necessary. I never used a charge controller on the smaller panel, although werre I to get another one, I would go ahead and buy a charge controller.

The second item you show does come with a 7A charge controller. It is a crude charge controller and I have burned one up in the past, but know I have two of that exact panel waiting to go onto my sailboat. The charge controller will do an OKAY job of managing current flow and will prevent cooking the batteries. I had this panel on the main house bank on the same wooden Chris Craft boat and it kept the house bank charged enough to stay up with the bilge pump that ran every 5 minutes. Thank goodness I did not burn up a charge controller on that boat or I would have sunk.

Let me point you in another direction though. Solar power is CHEAP right now. So much so that I have recently purchased two 40W panels to use at my lake spot. I am going to use them to power my outdoor lights, replacing the very inefficient and costly-to-operate low-voltage lighting transformers. Sunforce is bucking the trend and is NOT lowering their prices, so much so that they are not competitive in today's marketplace.

Here is a link to the 40W panel I recently bought: http://www.solarblvd.com/Solar-Panels-&-Systems-Individual-Solar-Panels-20---50-Watt-(6)/c1_25_40/p1401/Solar-Cynergy-40-Watt-12-Volt-Solar-Panel/product_info.html?osCsid=4406592f2910e5d7d942238ff 4b71b18

Here is a link to the very nice charge controller I recently bought: http://www.solarblvd.com/Charge-Controllers-PWM-Charge-Controllers-Morningstar-Charge-Controllers/c6_48_100/p629/Morningstar-Sunsaver-SS-10L-10A,-12V-Charge-Controller/product_info.html

For $111.16 plus freight, you can have a solar charging system that will replace lost juice at a rate approaching 3x what you picked out with the bigger of the two Sunforce brand devices, AND you will get a real Pulse Width Modulated charge controller, as opposed to the little device you get with the Sunforce.

Hope this takes you in a better direction and provides you with a more powerful, more rugged solution.

Phil
Kicker

[philwsailz]

Here is a 15-watt panel for $18.00, just to put it in perspective


http://www.solarblvd.com/Solar-Panels-&-Systems-Individual-Solar-Panels-3---19-Watt-(9)/c1_25_39/p2720/W-Solar-Monocrystalline-15-Watt-12-Volt-Solar-Panel/product_info.html


I like the Sunforce stuff and except for the one burned controller I have had zero issues with it. that being said, there are way cheaper and/or more powerful ways to do it today....

[tcallis]

Everyone thanks for the input. I'm going to use the set-up that Phil from Kicker recommended (Thanks for sharing your insight, Phil). I'm looking forward to tinkering with this stuff.

[ISUclonesrule]

I know this is a old post but I am looking at a solar set up for my boat because I too store mine at the lake with no power options. Would I need two separate setups to charge/maintain my dual batteries?

[philwsailz]

I know this is a old post but I am looking at a solar set up for my boat because I too store mine at the lake with no power options. Would I need two separate setups to charge/maintain my dual batteries?

You really have two options. Get a properly-sized panel and charge controller like I shared above, and then add a Blue Sea Systems 7610 Automatic Charge Relay, (ACR) like shown here:
http://www.amazon.com/Blue-Sea-Systems-Automatc-Charging/dp/B000OTIPDQ

Or just buy two panels and two charge controllers. The nice thing about installing the Blue Sea ACR though is that you will charge, (or maintain, depending on what panel you get) both batteries by solar, but you ALSO will be able to charge both batteries while the motor is running.

Phil
Kicker