Optimate TM-500 6-Step 12V/12.8V 2A Sealed DC to DC Battery Saving Charger & Maintainer

I've been looking for a product that offers what the OptiMate TM-500 does for over 6 months and I'm delighted to have finally found it, and report that it delivers.Why would you need this?You have a vehicle that sits for extended periods of time resulting in the car battery becoming discharged. For whatever reason you cannot reach an AC power outlet, and as a result a typical smart battery charger cannot be used.We realized that we had this problem with the car my son had with him away at college at New Mexico Tech. First we bought a combo jump start battery / air compressor unit (Stanley), which kept him from being stranded with a low battery. The jump start battery supplies a lot of current all at once to allow your vehicle to start. That's great, but because my son doesn't drive the car a lot, the car battery never got fully charged. Using a jump start battery to directly recharge a car battery fully is likely dangerous compared to a smart charger with an algorithm that monitors the charging process and supports a float / maintenance mode.Next we tried a 10W solar panel with an integrated smart charger. This would have been fine for maintaining a charge, but at just over 400mA of supplied current, delivered only when the sun was shining, was not sufficient to bring the car battery back from a deep discharge over the 3 weeks we tried this.Using Optimate, and the jump start battery as a supply source, solves the problem. We connected the Optimate’s charging port to the car battery and then the input cables to the jump start battery. This delivers a monitored 2A charge and will automatically switch to float mode to prevent damage to the car battery.The unit also claims to bring back damaged batteries that have as low as one volt left, which I have not tested.As a bonus, the cables have what I infer is an SAE spec connector for the input and output connections that allow the use of some of the Deltran Battery Tender adapters such as the OBD port charging adapter.Awesome product!

Once you get past how insanely overpriced this is, its a good buy. The connectors kind of suck, they are hard to secure.. but it works. But its the only DC-DC option out there, so thats just how it is.

Excellent solution for what seemed to be a pretty hard to solve problem. Remotely stored car with no AC power available and its a PITA to pull the battery in and out of vehicle. Very few products on the market provide reliable, metered battery to battery charging. Other than CTEK this is the only thing I could find. I love CTEK products but this was cheaper and I thought I'd roll the dice. This is working great so far. I'm using an old deep cycle as my source and every few months when I'm in the area where the car is I just grab the source battery and toss it in my truck to take home and recondition overnight.This will drain your source all the way down to 10 volts, so make sure your source can handle the abuse. Or use a battery with a year of warranty left as your source and beat the hell out of it for 9 months and take it in for a new one. Not something I'd do, but I don't judge.

This is a terrific product, I held back on one star because I feel like it should come with a 12vdc cigarette lighter plug ( I attached my own ). It does come with nice clamps. I use it to maintain the battery in my motorcycle via a 12v lighter plug into another vehicle.

Worked like a charm for somewhere between 2 and 3 weeks to maintain a 12V starter battery from my boat's 12V house battery bank. However, somewhere in the third week this charger died. Came back to my boat and no status lights working. Disconnect, reconnect,...nothing.The 15 Amp fuse is still intact. Thankfully this happened within Amazon's return window.

I am using four 100-watt solar panels to charge a 12-volt marine deep-cycle battery. That battery is used to charge other batteries (AAA- AA- C- D-cell, and 9 volt, as well as cell phone and other USB-charged batteries) using battery chargers that have a 12-volt input. But I also am powering various motion-sensing lights in the house from a sealed 12-volt lead-acid battery, and needed a way to charge IT. This little charger does the job beautifully. I can charge the small sealed 12-volt batteries (one in use and others as stand-by replacements) overnight, without having to use an inverter to run a separate battery charger for the smaller 12-vold sealed lead acid batteries. Kudos to the makers of this little charger!

Charge... charge... charge... all I get is an orange light... it does charge, but you can’t tell if its close or it’s overcharging.

This is an updated revised review of the OptiMate DC-DC charger after six months of usage:In my previous review I commented on the maintenance mode charging voltage high and low point being too low for my liking. Well it turns out that I was wrong in my assumption. I was basing my comment on Float voltages, not Trickle Charge Maintenance voltages.But my original criticism stands that I don't think this charger is ideal for an AGM maintenance trickle charger. AGMs ideally require a trickle charge On & Off point of 12.75 and 13.5V.The Optimate charger On & Off voltages are about 12.58 & 13.5.But for wet cell batteries, this is one nifty charger. I now give it 5 stars.

Awesome little battery charger. Using 12V input voltage from solar batteries to charge & maintain 12V tractor battery.

My bike is stored in a container with no power. The battery is difficult to access due to the fairings. This is the perfect solution, very easy to set up and use.

Ein super Ladegerät.Betreibe es an einer Autobatterie um meine Motorrad Batterie zu laden bez. Bei längerer Standzeit zu erhalten. Hat auch eine tiefenentladene Batterie ( unter 7 Volt) wieder aufgearbeitet.Lief dann über 24 Stunden aber Seiten keine Probleme mehr gehabt mit dem bikeKann es nur empfehlen....

Cumple de sobra con lo especificado. El mantenedor coche/moto perfecto.

•Ik parkeer de auto op straat en was het beu om de accu voor het opladen steeds uit en in te bouwen. Door deze lader hoeft dat ook niet meer! Heerlijk.•Op de foto ziet u de bronaccu rechts (blauw) en de doelaccu links (de grijze). De lader ligt boven de twee accu’s.•Lader werkt automatisch en schakelt uit als de bronaccu bijna leeg is.