Charging voltage for T-105s
Continuing my quest to learn everything I can about batteries and charging... Moved on from the group 24 Interstate, may mess with it more later. Also put the hydrometer with the floating balls whe...
Forum Discussion
RDMueller wrote:
Had some time today to test the Schumacher again. After seeing the charging voltage rise to 8.1 when individually charging a Trojan 6V, I wasn't about to subject them to that again. But I have a group 24 sitting around that I didn't mind trying it on and I wanted to see how it performed charging a 12V jug.
Started with the battery at about 50% and connected the Schu. Within a few minutes it was charging in the low 13V range and over the next few hours slowly rose to about 14.3V. Then when the battery was about 90% (according to the charger) the voltage jumped to 16V and stayed there until it reached 100% and it dropped to float.
It appears that this particular charger (SC-10030A) is designed to charge at 16V (8V for 6V battery) during absorption! Not sure any battery manufacturer would agree with that charge profile.
Also went to the Schumacher website and found a Q&A section for this charger. Someone posted a question asking about charging voltage and the Schumacher tech responded with the following:
"These units will put out variable voltage, based on the battery type and the stage of charge it is in. The lower voltage levels will be in the initial stages and the maximum voltage levels are reached in the last stage. For standard, wet cell battery types, the maximum it will reach is 16V; for AGM batteries, the maximum is 15.4V and for gel cell batteries, the maximum is 14.7V. Setting the charger for the battery type you are charging will get your battery charged completely and properly."
So, it seems to me if I want the 14.8V that Trojan recommends, I could just select gel cell and it would get me pretty close. Still amazing to me these chargers go that high! Frankly 14.7 is too high for a gel IIRC.
Remember 14.7 is towards the "end" of the charge cycle. At this time amps are low. At this point voltage can be raised. The higher voltage allows amps to be pushed in faster. Google "UIU" charging if you wish to understand it better. Its more then a top charge and easer on the battery then a full equalize.
