Ring RSC612 12A Smart Battery Charger, 12V Vehicles to 5.0L, All Battery Types, Stop/Start, 7 Stage Charge Cycle, Repair Functions, 4 Diagnostic Tests, Black

The charger works well. I asked their support line why it never reaches 100% when you auto charge. This is their reply. “ ignore the % value, and concentrate on the current value, shown next to the A on the rhs lower part of the screen.Irrespective of the % value, when the current is 0A, no more charging will take place.”

I don't write many reviews, but I have waited for this Amazon invite to share my experience.My problem was a flat battery for a BMW 320D with start stop - AGM 95 Ah.First, if you have never used a smart charger before, be aware that they do need the battery to have some life; 1-2V at the terminals or the charger does not sense the battery connection and will not charge - not smart!!This RING unit will not charge a dead battery - if you connect a dead battery it will give the appearance of doing something, but in fact it is doing nothing. I had to use an old charger to push some amps in and register some life, then the RING charger could sense the battery and do some work.Next - don't be fooled by the 10-12A capacity - you don't need it unless you are charging batteries all the time. I never saw this unit deliver more than 5A.Once the unit was working, I found it did register full charge after about 30 hours (!). The battery recovery mode did not give me confidence it had achieved much. I disconnected, rested and reconnected to check the battery again to find it stating 60% charge. 60% charge seems to be a default start point. The unit quickly cycled up to 100% charge but it gave me little confidence.I found the instructions with errors, and and when I tried to contact the RING technical team for advice (phone and e-mail) I got no reply (CV-19 no excuse).The 12V cables are too short and the terminal clips too small to firmly clamp onto the battery terminals.After 4 days (yes 4 days, and I am not dim) of messing around on one battery, the unit gave an error code, so I sent it back - thanks to Amazon for the simple return process.I bought a NOCO Genius 5 (same price and next day) and what a difference - the NOCO unit did what the instructions said it would do, and it is now left connected long term to maintain a trickle charge to the battery.Finally, don't be fooled by the 2015 awards for the RING unit as I was - 5 years is a long time and there are now far better chargers available at the same price.I do recommend the NOCO Genius 5, which will charge a totally dead battery, and the battery recovery cycle does work ( I did two recovery cycles) - the little green indicator is glowing again. I have used it on a second dead battery and same positive result - easy to work with.That is my experience.

Easy to set up and use good buy

Not the latest smart battery charger, but a very reliable and well tested device. Lots of features for checking your battery, as well as advanced features for "smart maintenance" of your battery. Although it does have a feature for recovering totally flat batteries, this isn't the best for doing that. It is for battery maintenance -- ensuring the longest life from a new battery -- rather than recharging a battery that's past its best. A shame it didn't come with a storage bag. Instructions are printed so small they're illegible unless you have a magnifying glass. Better to watch the YouTube videos, then phone technical support. Duh! When will developers of clever tools take the trouble to explain how they work?!!There's a gotcha that has had me scratching my head a few times. The charger works in one of two modes: as a charger and as a tester. In testing mode, it doesn't have to be plugged in to a power supply. In charging mode, it needs a 240V AC power supply. (That sounds obvious, eh?) Well, if you ever find it's impossible to switch out of test mode and get the thing to offer a charging mode on that LCD Screen (the buttons don't seem to be responding) yet the display is on, then you've forgotten to throw the "on" switch at the power socket or the 13A fuse has blown or the safety circuit breaker has tripped. Everything appears to be working, but the charger is drawing its power off the battery you're intending to charge, rather than from the 240V mains. It has no power to charge, so isn't offering that option. Just a shame the LCD display doesn't say so, or that they didn't put a power LED on the thing.

I needed a 'Smart Charger' that would be able to cope with different sized batteries, i.e. Ride on Mower, Caravan, 3.0 litre Diesel Car and HGV. It would also need to be able to diagnose the Battery Condition, check for Alternator Faults, Starter Faults, be suitable for 'Start/Stop' vehicles and maintain Optimal Charge Levels.This unit appeared to tick all the boxes at a very reasonable price and as an added bonus, it has a Memory function that will retain the vehicle and audio settings whilst replacing the battery. I must admit that I am most impressed! It appears to be Very Well Constructed, Knock Proof and with a clear and concise Illuminated LCD Display. Other reviewers complain about the manual but I found it pretty straight forward, well, apart from 1. You need a magnifying glass to read the tiny print under the pictograms. 2. Poor Instructions for the 'Retain Memory' Procedure (see below). It must be noted that this is NOT a Fast/Rapid Charger! It charges your battery slowly and carefully to optimize the battery performance. Simply press 'Auto' or select your preferred charge settings. There is also an excellent basic instructional video on the Ring website.EDIT..... As the instructions are so poor with regard to the 'Retain Memory' Function and I could find no information on the web, I have shown them here: Connect the charger to the vehicle battery terminals (ensuring that you can still access the terminal nuts), plug the charger into the mains, Select Memory, Disconnect and remove the battery from the vehicle (ENSURING THAT THE CHARGER IS CONTINUOUSLY CONNECTED TO THE VEHICLE'S BATTERY LEAD TERMINALS, PLUGGED INTO THE MAINS AND 'MEM' IS FLASHING ON THE CHARGER), Carefully fit and connect the new battery. ONLY THEN can you switch off an disconnect the charger.