I purchased this charger after having had an Optimate 4 for a while. When the new charger arrived I noticed it's was super lightweight compared to the older one. I was a bit disappointed since other solid state battery chargers had failed early in their service life. But I kept it because the old one had lasted. This one failed 3 months later. The charge light comes on and stays on, but no current flows according to my clamp meter.I have filled out a warranty request form at the Optimate website and waiting for a response. I'll update this accordingly after I get warranty service (or do not).UPDATE - changed ratingI contacted their support department and after some diagnostics they sent me a new unit.I have had their products in my garage for about 15 years and this was the first time I had had a problem.A quick resolution restored my faith. Good product, good support after the sale.This is way better than the different cheap one that I bought.The OptiMate 5 is hands down the best battery maintainer money can buy. I have had this now for about 6 months and every time I want to ride my motorcycle, I CAN!Gone are the days where I would go to start my bike and hear the ubiquitous clicking noise. I used to have the itch to go ride and then I'd have to charge up the battery and by then, I didn't want to ride anymore. This was the best purchase I have made in a while, as it has directly resulted in more riding time and absolutely ZERO hassle.This maintainer DOES NOT CHARGE YOUR DEAD BATTERY! It was not intended to do that. It just cycles the battery and keeps it topped off. You must charge your battery prior to plugging this in.I highly recommend you get multiple pigtails to hook up to all your outdoor toys/tools and you can then keep all of your items fully charged!I have been very impressed with the way this works. It doesn't make any noise like other battery chargers I have used in the past, it won't cause thermal runaway and it has brought back several of my batteries from the dead after a short charge from my main battery charger. I have even refreshed a 12 year old Harley battery with this thing.Imagine the money saved over the years, imagine riding your bike whenever you please.Buy one of these and stop dreaming!Through Astronomers Without Borders we just installed East Africa's first dedicated astronomical observatory in rural Tanzania! The telescope is operated by a 12V car battery which is continuously charged by this unit. I spent days in research before heading to Tanzania, making certain I could find a unit that could receive 240V in and be connected to a battery while in operation. It worked flawlessly. We even mounted the charge on the wall so that the unit was out of the way, and less likely to get bumped when observing the night sky.The headline says it all. Real upside is the 110v and 220v operation. Comes with a US plug. A solid plug converter would have been 6 stars.Using Optimate 5 Votmatic for the last 5 years on lawnmower, motorcycle and auto batteries. Successfully recovered assumed dead 8 yr old 07 FJ cruiser Panasonic battery which lasted another 6 yrs. Lawnmower battery is doing well after 6yrs with seasonal 4 month storage cycles.I got the OptiMate 5 charger with the 15' extension and Weatherproof Permanent lead through Amazon about 1 1/2 months ago. I Had a smaller older one that worked very well so wanted a second better one with a couple more benefits. It brought back a weak battery at least for a little bit longer and keeps my other batters charged at all times. I use for Generator and a lift I have and electric golf kart. I'm a contractor so not messing with dead batteries all the time now. Not for jump starting and fast charging but great for maintaining and long term . You can just leave it hooked up and not worry about it, but your battery will always be charged. There is a connector where you can connect 5 batteries to one charger at the same time too.This the 3rd OptiMate I have purchased. I have an old OptiMate for my Motorcycle. I've that one for 10 years +. It has always performed well. I purchased my first OptiMate 5 for work to charge gel batteries on Electric Hydraulic Lift tables. The chargers that are attached to these will not charge the battery if the level gets too low. I am positive that these batteries were replaced prematurely in the past because of the lousy chargers.The OptiMate 5 recovered them in less than 24 hours. I purchased the 2nd OptiMate 5 for my Mazda MX-5 Miata to keep the battery charge during the winter months.I have a 2006 Porsche that I store in the winter. I let the battery completely die by mistake. My friend, who’s a mechanic, recommended this product and I was able to get the battery charged.works as advertised, amazing product very good qualityand input voltage is versatile you can use it anywhere in the worldBought the same model years ago from Amazon. Died on me. So got the same one again..... From Amazon.....Work greatjust purchased a couple months. looks it works as advertised. will know in the spring.