Battery Tender 35 Watt Solar Panel 12V Battery Charger with Charge Controller - IP67 Weatherproof - Mountable Smart Charger - 021-1174

Hooked up to a deep cycle battery and installed on a fuel cell. Can fill multiple pieces of equipment daily.

Best solar charger and battery tender.I have 2 units over the last 10 years

Bought one a couple years ago and it works great. Bought a second one a few weeks ago and it doesn’t work. Can’t send it back to Amazon because they’re no longer available

I have had one of these chargers for many, many years and recently bought a second. The first one has been absolutely great for keeping batteries charged. I am using it to maintain the battery in my box trailer. When someone left the 12V LED interior lights on for a few days before that mistake was discovered, this charger prevented the battery from being killed and quickly returned it to 100% charge. The downside: the new one I purchased has the solar panel wired backwards. This was solved by adding a gender changer before the charge controller, but is disappointing that the problem got passed Battery Tender QA. A friend of mine recently bought one of these units and had the same issue. I expect it was a bad build batch as the old one I have does not have a problem. The solar panel is strong enough to work while inside a car placed in the front windshield (while parked - don't drive with it there). With some additional equipment to connect the charge controller to your car, it can keep your battery charged while staying securely inside your vehicle even while your are away on a trip. I highly recommend these chargers though I would like to see Battery Tender take a closer look at their QA process.

Keeps me from having to make sure my dump trailer is charged up.

The old design had the charger control integrated into the housing of the panel.Impossible to lose, and convenient.The new design removes the controller and had it in it's own little case that plugs in between the cord from the panel and the cord of the battery connection. So if you're mounting the panel on the roof, now you'll have this little dongle flopping around somewhere else. And of course, you'll have to make sure it doesn't get separated from the panel.Not an improvement

I put this on my dump trailer to keep the battery charged, its a bit overkill but I wanted a quick battery recovery between dumps. definatly worth the money.

I’ve never had a problem with Deltron/Battery Tender products. This is no different. I’m using it to keep the battery charged on the Motorhome generator. Placed it on the roof. Could easily be permanently installed.