solar battery charger are they safe?

[minocqa]

hi<br />i have been seaching this forum and have seen many posts about the solar battery chargers<br />my boat sits for a couple of weeks at a time<br />so i think this would be exactly what i need.<br />has anyone ever had any probelms with them?<br />i just dont want any fires from shorting out.<br />i found one on ebay the guy says it produces <br />1.8 watts and 125 mamps. <br />is that about average?<br />thanks <br />Don

 

[crazy charlie]

Re: solar battery charger are they safe?

That sounds like the minimum.They are very safe .Make sure they have a diode that prevents against nightime drain.I would recommend not getting the minimum.That is a battery maintainer.If you have anything like a clock or alarm or an lcd in a stereo ,it wont be enough.Charlie

 

[AaronG]

Re: solar battery charger are they safe?

Your concern about fire from shorting out is a very valid concern. Make sure you propery fuse it. It isn't the charger's output that could cause a dangerous short, its the battery that its charging. I've heard of this happening on large sailboats in the past.

 

[AJ168]

Re: solar battery charger are they safe?

I use one of the cheaper ones that came from Harbor Freight. Although I don't use it on my boat, I do use it to keep my quad and lawn tractor batteries charged up over the winter, my trolling motor battery topped during the boating season. I've had it for 3 years now, constantly hooked up, and have never had any kind of problem with it. I don't use it outside, but if you bought a better quality one it would probably be just fine.

 

[minocqa]

Re: solar battery charger are they safe?

thanks for the replies<br />shorting out is a real concern to me, what size fuse? would you use on this?<br />OR should i look for a solar charger that has more watts? the one on ebay is like 20 dollars<br />thanks again<br />Don

 

[minocqa]

Re: solar battery charger are they safe?

i found this one also<br />Panel produces 18.8 volts 3.2 watts @170 m amps

 

[ZodFutMk2]

Re: solar battery charger are they safe?

The Harbor Freight units are not sealed, at least not mine. Use them outside and get moisture build up under the plastic lens. Doesn't seem to cause any problems though and they've been out in the yard for about six years.

 

[minocqa]

Re: solar battery charger are they safe?

ok thanks<br />we have one of those stores here in town<br />i'll check them out

 

[Boomyal]

Re: solar battery charger are they safe?

You not only need to protect from nite time drain back, you need a regulator or it will boil your battery dry.

 

[Dunaruna]

Re: solar battery charger are they safe?

I doubt that 1 or 2 tenths of an amp per hour (at best!) will boil the batt dry, have you had problems with small panels, boom?

 

[AaronG]

Re: solar battery charger are they safe?

A small fuse will work fine. I'd probably use 5 amp. Put the fuse as close to the battery as you can.

 

[Boomyal]

Re: solar battery charger are they safe?

Originally posted by Dunaruna:<br /> I doubt that 1 or 2 tenths of an amp per hour (at best!) will boil the batt dry, have you had problems with small panels, boom?

Years back when I had my houseboat, I got tired of dead batteries at the beginning of the season. I bought a foot square charger, made with the natural stuff instead of the synthetic stuff (forget what the natural stuff is called). It's whatever Bell Laboratories used back in the early fifties when the built the first Photovoltaic cells ( which are still producing electricity today) <br /><br />Hooked it direct to the battery. When I returned in the spring, the battery was absolutely dry. Talked to the supplier and they sold me a solid state regulator and problem was solved.<br /><br />I still have that setup today. Took it off the houseboat when I moved and had to sell it. It just doesn't work very well with 9 mo's of clouds.

 

[Dunaruna]

Re: solar battery charger are they safe?

monocrystalline, cut from a single piece of crystal. The most efficient, but also the most expensive.<br /><br />That is what I run on my boat.

 

[imported_Curmudgeon]

Re: solar battery charger are they safe?

Most likely the panels you're seeing on Ebay are from Volkswagons (factory installs 'em for shipping). Not sure if they're waterproof or prevent reverse current drainage.<br /><br />The two well-known marine stores have similar units for just a little more than you'll pay with Ebay. The Westerly one blocks reverse current, has a great warrantee, and comes with battery clips and plug. Units of this size do not require regulation and cannot boil a battery (you can create just about as much power by rubbing your hands together in winter).<br /><br />Be aware these units are designed to maintain batteries when not in use - it will not "charge" the battery, nor will it recover the battery from any continuous drain of any size. If you want to get into any of that, you'll need a much larger/more expensive setup.

 

[minocqa]

Re: solar battery charger are they safe?

thanks for the repsonse<br />what i'm really looking for is a charger that is used mainly is to keep my auxilary battery charged for my bilge pump.

 

[imported_Curmudgeon]

Re: solar battery charger are they safe?

Just remember, most inexpensive solars are "maintainers", and not "rechargers". Bilge pumps take draw 2 to 5 amps, which gives you an idea of how long it takes for replacement at 125mA (during daylight hours only).