solar charger

[oldboat1]

I have an electric start trolling motor on a larger boat I keep in a slip. Just bought a solar charger for the little motor?s starting battery that is in a battery box at the stern ?-- $25 at Tractor Supply. It?s a Coleman 2amp charger.

I hung around a little after hooking it up to see if it was charging, and think it is. I had only a portable state-of-charge meter on the boat, but see a slight increase in charge after sitting around reading the Sunday paper for a while, so think it?s probably working OK. Do these little rascals heat up with use? I have it on top of the battery box, with a bungie cord to keep it in place with any rocking or wind action. I also cleverly used the molded plastic top of the bubble pack to cover it from rain ? think it?s probably not waterproof.

It looks like the recommended application is at the windshield, attached by supplied suction cups (which probably have no chance of holding). Additionally, it seems to me that summer heat at the windshield would be pretty high. It?s a plastic case, after all.

Any thoughts on using these devices? It?s use and application issues I?m most curious about, in an actual boat in the actual weather. I don?t want to bother with any wiring to the regular house or starting batteries or the onboard charging system ? and figure a 2amp trickle charge would be fine. The little 9.9 puts out only 5amps, I think, and that would be at higher rpms.

[BTW -- deep cycle marine battery. I mention that because an auto supply store clerk mentioned that our Mennonite neighbors here (finger lakes, upstate NY) use these chargers for running lights on their buggies -- have the idea the batteries in use would be small lawnmower/motorcycle batteries. Anyway, I figure ongoing use on a marine deep cycle would likely be fine, and would like to just leave it connected. Any history of boat use would be nice, particularly if there are some hazards....]

 

[bruceb58]

A solar charger the size of which you purchased is only going to be good enough to maintain a charge on a fully charged battery. Something that will recharge your battery in a couple days time will be as big as your boat.

 

[Silvertip]

You didn't buy a 2 amp panel. You bought a 2 watt panel. A 2 amp panel outputs about 25 watts and sells for much more money.

 

[oldboat1]

yes. Thanks -- stand corrected. 12v, 2w. Used one?

 

[ondarvr]

It shouldn't cause any problems, because there is so little power being produced it won't have an effect on anything, including charging the battery.

Plus if you covered it with plastic it will reduce the output even more.

 

[oldboat1]

think I sense a trend here -- believe I'll explore a more portable battery for my use -- and charging options (12v motorcycle, if enough cranking amps for the little motor). solar charger still might help maintain charge. Miss the old deep cycle in the shop anyway.

 

[ondarvr]

How much do you use the small motor.

 

[oldboat1]

maybe once a month at most. I fire it up a couple of times a week just to make sure it's ready when I want it -- heat it up to temp., but maybe only five or ten minutes. It's not long enough to put a serious charge on the battery. My current battery is about five years old -- too old to keep a full charge without some help. Could get by (not much draw with the little starter), but thought I would just maintain it a little with a trickle charge.

 

[NYBo]

If worse comes to worst, you can pull-start the motor.

Off topic. LOVE the Finger Lakes. Plan on retiring to a lakefront house on Seneca.

 

[oldboat1]

nah -- still related. I wanted to use the kicker for slow trolling (lakers) but haven't gotten around to it much, yet. No excuse either (except summer traffic on Keuka). Seneca is really interesting, as you probably know well -- huge and deep. I've got deep (kind of amazing really, 100' plus just a little offshore), but a little smaller than Seneca, and seems easier to handle to me. Great retirement spots on Seneca, really any of the lakes. 600' depth on Seneca. geez.

[motor starts well, but kind of awkward to pull start -- age (me) and location (motor). Know there is a conversion to vertical pull, some old motors anyway, but like the elec. start. Have a little steering console back there, and controls. Old Trojan F26 that now looks a little like a tuna boat.... but it all comes off]

 

[TCATTC]

I use the same kind of Coleman unit. Mine stays on top in all weather. Water will not hurt it.

 

[oldboat1]

Thanks, TC. Good hands-on feedback. Mine seems to be maintaining and bumping the charge slightly after a day or so -- forgot to check tonight when I was out at the boat. There is some helpful feedback on Amazon -- some technical analysis, output measurements in mA, and overall function. Generally positive. Some were disappointed. So far seems fine as a trickle charger, and think I'll just continue on with it.

 

[bruceb58]

The problem is that if you leave your batteries in a discharged state and just have this charger on it, you will ruin your batteries. This thing is only good connected to a fully charged battery to maintain its charge..noting else.

 

[oldboat1]

...and it appears to work well for that. Good with it so far.

 

[bruceb58]

...and it appears to work well for that. Good with it so far.

So you are fully charging your battery before you put it on?

 

[oldboat1]

F26 batteries are fully charged by the onboard shore power charger. Main and house batteries are topped off as needed. Starting battery for the troller (battery at issue) gets fully charged, drops to about 80-90% after flash charge, and like to maintain around there -- separate from the onboard system.

 

[ondarvr]

It seems people don't realize how little power these cheap 2 watt chargers supply. They are rated at 2 watts in perfect conditions with the best possible view of the sun at high noon, anything but perfect alignment can reduce the power supplied dramatically.

Even trying to keep a fully charged battery up to snuff would be stretching their capabilities past what they can actually do.

It's one of those feel-good things that seems like a good idea, but doesn't really have any facts to support it.

I'm not saying solar power won't work, only that this isn't one of the options that has much value.
For it to work you need to bump up the size of the panel so it can supply 1.5 to 2 amps (not watts) for an extended period of time, even in less than ideal conditions. This would just maintain the battery, to actually charge the battery you need an even bigger panel that would put out enough amps so that you can make some headway during the limited amount of time the panel is actually producing power.

 

[oldboat1]

don't think you should use one, then, ondarvr. A charger and extension cord can work too.

seems to be working fine for what I need (Amazon feedback instructive too, for anyone interested.)

 

[ondarvr]

don't think you should use one, then, ondarvr. A charger and extension cord can work too.

seems to be working fine for what I need (Amazon feedback instructive too, for anyone interested.)

What people on Amazon say about solar charges means little, look at the facts, as in what power a panel produces, and what is needed to charge a battery. Those facts don't play well for these small cheap panels.

 

[ondarvr]

You do understand these 2 watt panels only put out .166 amps on their best day, that's .166 not 1.66