Hi purchased a Noco Smart Charger 3.5A unfortunately I can only put on the car once a week generally on a evening for around 4 hours but what I’ve noticed is that in that time the charge process will only get above 50% but not upto 75% fully charged.
I have also access to a Yuasa YCX25 25A which I can put on the battery and within 5-10 minutes reads fully charged then if I attach my Noco unit straight back on within minutes it will read fully charged.
Should the Noco unit take so long to charge back to full if left a week or would you say the Noco unit is not working correctly.
When finsihed the battery reads 12.7Volts and 350CCA the battery was a 390CCA from new. Pre charge 12.1 volts 340CCA.
So looking at the chart, looks like i’m not giving it enough time, 6/7 hours plus with charging in colder temperatures at night and 20ft extension accesorie lead from charger all comes into play.
If the battery is a good one, like the YUASA 48AH in my NC, but low on charge, then the NOCO can take ages (up to 15 hours) because it is only providing 3.5A, and it also backs off the rate as the battery approaches full, simply to keep the battery temperature down and therefore maximise its operating life.
I have such a NOCO and think it is brilliant. When I fitted the new YUASA, it took overnight to charge because judging by the manufacturing date-code and scheduled imminent re-charge date it had been on a shelf in the warehouse or ship for many months.
With a properly intelligent Smart charger (like the NOCO), this is a Good Thing, it shows the battery has lots of storage capacity!
If the battery is going down too soon, check the ‘dark’ currents in the car and the age of the battery.
In theory the YUASA in my NC should last for almost two months before it is too flat to start the car, but I usually drive it more frequently than that, and also if not used for a couple of weeks or only short journeys I give it a top up anyway.
I also have the NOCO 3500 and can offer up one thing I have experienced / learnt. Probably not so relevant now but there is definitely a difference between the 12V Norm and 12V Cold/AGM settings. During the winter it struggled to charge the MX on Norm but as soon as I used the Cold setting the charging cycle completed and held okay. That is using it outside under a carport and charging every couple of weeks so the battery was never completely flat mind you.
First few times I used it I did select Cold/AGM after reading the instructions and the temperature has risen a bit I changed to Norm mode and didn’t think much about it thinking the cold setting would throttle it back a bit.Will try switching bact to Cold/AGM
Taken charger into work yesterday to test on new fully charged batteries.
Two hours later stuck on 50% unplugged the charger plugged back in within 10-15 mins fully charged
Same thing happend on two other batteries so took it home last night put on my battery stuck for 4 hours on 50% unpluged repluged back in, full with 10-15 minutes.