Thread: Problem Charging Aux Batteries with Smart Charger

Originally Posted by LRD414

As per my earlier post, my Ctek MXS 5A charger works perfectly for your exact setup. Note that my cable to the rear Anderson came with the D4-5S Traxide kit so it may be a larger gauge than yours and if so this would be the only difference to you. I don’t disconnect the Traxide and it doesn’t cause any issues for the charger getting to float.

Scott

Thanks I think I'll get a ctek charger . I would just like the thing to work every time and predictably and this charger I have is just not doing that . Do you run your ctek 5 amp on the normal setting or the AGM setting ....given your anderson plug is going back to your optima like mine ?
I am using a fairly thick wire I think it's 6 AWG but I do have a short section of thinner wire close to the battery that has an inline 30 amp fuse . Not sure if this would make a difference .

Hi Landoman, I looked up the specs for your battery charger and it actually states that it can take up to 55 hours before the charger automatically goes into float mode, but it also states that the maximum total battery capacity it is designed to charge is 120Ah.


While you have around 145Ah of total battery capacity, and you are only just above what the charger should be able to handle, so it should be fine but will take longer to complete a full charge cycle.


The fact the charger goes into float when in the NORMAL setting but not while in the AGM setting may simply be caused by the slightly large battery capacity than it is designed for.


In any case, because it works properly in the NORMAL setting, I personally would just just keep the charger you have and leave it set in the NORMAL setting at all times.


The only difference between the NORMAL and the AGM setting is the voltage used in the final stage of the ABSORPTION mode. This is 14.4v vs 14.7v and is pretty well irrelevant because both voltage levels will get both batteries fully charged.


The only suggest I would make is to carry out charging your batteries with the battery charger a little more often.