Solar Battery Charger/Maintainer

[GrizzlyGuy]

I don't ride in the winter like a lot of you guys do. I would, but we made the mistake of buying a house with only a 2-car garage.

So instead of riding, I focus on skiing and store the Grizzlies out back in the Grizzly Den. The Grizzly Den has no power:



In past years, I removed the batteries and connected them to battery maintainers in the garage. It was a hassle to do this and last year I somehow lost one of the "battery nuts". Lucky for me, the Polaris dealer in town had one in his junk parts can or else I would've had to buy a new battery.

This year I happened to look up in the sky and saw my solution: the sun.

I bought this BatteryMINDer 5W solar battery charger/maintainer from Northern Tool and Equipment for $99 (ordered it via Amazon.com). I went with a 5W panel because I calculated that it should have plenty of juice to handle both Grizzly batteries. If you just need to charge/maintain a single battery, you could get a smaller panel. Or go with the 15W panel if you want to do more than 2 batteries. Any time you do more than 1 battery, be sure to connect the batteries in parallel (+ to + and - to -) and not series.

Here is what the 5W system looks like in the box:



This is what you get in the box. No, you don't get that Paiute Trail Map, I just tossed that onto the solar panel so you could see how big it is:



The solar panel comes with a bundle of wire so that you can put it on your roof. The large box to the upper-right is a charge controller. The solar panel voltage feeds into it, and it sends the correct amount of voltage/current out to your batteries. It comes with ring terminals that you can attach to and leave on your battery, with bullet connectors inline so that you can disconnect your battery/ATV from the system when you go ride.

I have my Grizzlies wired with a chunk of heavy gauge wire going to the battery and PowerPole connectors on the ends. I use this for powering the video gear, radio gear, and any other electronic gizmos I may have onboard. So I made some quick modifications to this system using some PowerPole accessories that I happened to have on hand:

1) I disconnected the bullet connector, tossed the ring terminal and inline fuse, and put one of these Bullet-PowerPole adapters in its place.

2) To the end of that, I connected a PowerPole Y cable so that I could connect to both ATVs at the same time. PowerWerx doesn't seem to sell those any more, but you can use one of these 4-port splitters instead. I have a bunch of those and they work great for connecting many gadgets to one power source.

3) I should have connected one of these fuse holders ahead of the Y-cable/splitter, but I didn't have a spare one on hand. The Geek Code of Conduct states that fuses are optional, so I decided to just double-check what I was doing and leave out the fuses.

Out to the Grizzly Den I went. I connected the solar panel to the charge controller. Putting the solar panel on the roof isn't an option for me because of the snow that hangs around on the roof. I have a SE facing window in the Grizzly Den, so I slapped the panel onto the window sill:



Then I plugged in each Grizzly, using my pre-wired PowerPole cable from each to plug into the Y ends (PowerPoles are sexless connectors so you can always connect any two PowerPoles together):





The green light on the charge controller came on, indicating that the batteries are charging:



So I headed back to the house and took a look at their instructions for the first time. Yup, those look like pretty good instructions, they said to do pretty much what I had just done (except for the bypassing the fuse part). You'll have to decide for yourself whether the Geek Code of Conduct applies to you or not.

I went back out a couple hours later, and the green light was now flashing. This means that the charge controller has switched to the maintenance mode, preventing your batteries from getting overcharged. The unit also has desulphation circuitry in case your battery has sat around a long time without use or maintenance charging. Mine were fine as-is, so this circuitry didn't engage.

All in all I'm lovin' this thing. Money well spent.

[trainman]

GG,
This is a great find. I keep my Rubicon in a shed across the driveway. Occasionally I run a cord over to it and hook it up to a Battery Tender. But this would work good for me too. Got to find my Northern catalog. Since we don't get a lot of snow here, I assume that it could be outside on the shed. Nice going again.
Thanks

[trainman]

Sorry to bring this thread back to the top, but I just discovered something that may work as a solar charger also, and much cheaper. Apparently Volkswagen and Audi cars come from Europe with a solar charger stuck on the inside of the windshield and plugged into the cigarette lighter to keep the battery charged whenever the car sees the light of day. They can be found on ebay if you search under VW solar charger. I checked and there are lots of them all the time. This should also work well for our batteries. You can get them for around 20$, plus about the same for shipping.

[GrizzlyGuy]

Yes Trainman, those types work fine for keeping a single battery topped off. Here is one from Amazon for less than $20:

http://www.amazon.com/Sunforce-50012-So ... B0006JO0KG

I use that one in the Hummer when I park it out on the street during summer (so that the Grizzlies can be in the garage).

[trainman]

Amazing, GG, I never even thought of this for my ATV battery, since your original discovery, they are everywhere. How many watts do you think one needs to do the job? The amazon one is 1.8, and some of the others are 4-5.

[GrizzlyGuy]

I'm thinking that the little 1.8W panel would be plenty to maintain a single ATV battery. We used to use those to maintain and actually charge the batteries in sailplanes down on the flight line (easier than hauling the battery in and out). The sailplane battery would be practically dead after a full day of flying with the radio and flight computer running.

The 5W panel would probably be better for multiple ATVs. We'll have to see how mine does by the end of this season. The snow out back is now so high that it is starting to block the window where I have the panel.

[hemingray]

Hi Eric,

Do you think there are any issues with a "Y" cable and an unequal battery condition? When I first looked at using two 12v AGM batteries in parallel with a Tripp-Lite inverter/charger as my pellet stove's UPS, I found differing opinions on the internet about batteries in parallel. I was especially concerned because I was using surplus AGM batteries from a UPS system and as they are 75AH and the charger side of the inverter can do 20 amps, I didn't want things to go bad! I still don't really know what an imbalance means to a charger - but Tripp-Lite has no issues with cells in parallel.

The cells were removed from the UPS as PM - they were 3 years old. I picked two cells that had similar voltages and things were OK for a year, but when I checked up on things in November, I found one of the two batteries was significantly warmer than the other - and had a lower voltage when isolated. I swapped it for another cell and things are OK. Interestingly, after a month off the charger, the bad cell had dropped to 8v, whereas the others I have were still up at 11-ish volts without a charge for months, so that one was probably bad.

Anyway - just wondering whether you thought of any issue with the two batteries on a single charger.

[Keith Strong]

Can that panel handle the weather being outside? Now that I store the quads in the enclosed trailer, I would love to do something like this but the panel would have to be outside.

[Kendo]

Can that panel handle the weather being outside?

Unless you have found a way to generate artificial sunlight indoors, I can't see how you could get away with it being anywhere BUT outside.

And if you HAVE found a way to make sunlight, I want in on the deal!!

[GrizzlyGuy]

Do you think there are any issues with a "Y" cable and an unequal battery condition?

Yes Dave, if you connect multiple batteries via a Y cable as I am doing, the batteries should be similar in terms of type and condition. Otherwise, the battery with the lowest voltage will take more current from the charger, and that could lead to problems like it overheating or maybe even exploding.

If you have batteries that are different, you should put a separate charge controller in front of each one and do the "Y" connection upstream of the controllers at the output from the solar panel. That would allow each controller to independently regulate the voltage/current for each battery.

Keith: The manual for the 5W panel I have says it is meant to mount outside and can take winds and weather (and probably even hail if the size we get around here). I just put it in my window sill for convenience.

The only precaution per the manual is to make sure there is air space behind the panel when you mount it (for cooling, I suppose). So you'd want to mount it using the provided brackets, or maybe up on standoffs. The cheaper 1.8 AHr panel I got from Amazon may not be weatherproof, not sure, I've always used it on the dash of my Hummer. For charging our sailplanes, we used to put them inside the canopy so they were shielded from the weather as well.