Meanwell is here!!

pnichols wrote:
IMHO, your post above was well written and outstanding re clear information transfer!

I believe you've just made the point that 15.XX volts should only be applied when certain conditions have beforehand been met with the battery(ies) .... not all the time as kindof an improved boost voltage whenever one wants to charge a wet cell. I'll have to slow down in my reading, as my reading of some of MEX's posts led me to believe that he might have been advocating the use of a simple and inexpensive adjustable voltage power supply to achieve 15.XX volts at high currents for charging of wet cells each and every time you charge them.

I thought that high wet cell battery charging voltages in excess of 14.XX volts were for such things as stirring the electrolyte within cells, for equalizing amoung the cells, etc., and as such was only occasionally required for wet cell battery maintenance.

Boy ... am I glad I use dry cells. :S

15.0V or slightly above (US Battery specifies 15.3V) is what is required to TOP CHARGE a Trojan T-1275 or a couple of GC2 batteries. I would consider a top charge to be perhaps 97 or 98% charged, I will defer to Mexico Wanderer on that, as the SG on a 97 or 98% charged battery still has more to go... there is still some residual sulfur on the lead plates, which causes the specific gravity to not be at it's highest, where a 100% charge would be.

To truly get to 100%, in my opinion, you have to get all the sulfur off the plates, which of course will probably cause the SG to be at as high as 1.280 in each cell. The only way I am aware of truly doing that is going to 16.0V from time to time, as needed, by using 16.0V at C/20 charge rate... about 10 or 11 amps continuous on a pair of GC-2s. About 7.5 amps on a 150 amp hour Trojan T-1275. About 5 Ah on a Group 29 and about 4 amps on a single Group 24, 8 amps on a pair of Group 24's. 10 amps on a pair of Group 27's or 29's. Constant amps, and let the voltage rise from 15.7 to 16.0, or until your SG stops rising. Still... it requires 16.0V. Not 14.4V, not 14.8V.

That, my friends, is a true 100% charge, when your SG is = to what it was when fully charged and brand new. Around 1.280 The Hydrometer never lies. Use it.

AGM's are a whole another matter.

Think of amps as volume of water coming out of a car wash. Think of voltage coming out of a high pressure car washer as pressure, scrubbing the plates on your cells. In order to overcome the sticky resistance of sulfur on lead acid plates, one must add more pressure (voltage) to deep scrub the plates. You don't deep scrub wash all the time, only when it really needs it. If you keep the pressure pretty regularly at 15.0V, most days, the plates on your battery take a long time to get dirty enough to need a deep cleaning session again.

Another analogy would be filling up a 210 foot (amp hour) water column, with the fitting for the filling being at the very bottom of the water column. You have all that weight of the water column, in pressure, to overcome, to fill that water column to the top. It takes pressure to overcome that water column weight, to fill up completely. Voltage increase is increasing that pressure, to overcome the weight of the water column. 16.0V worth.

Listen to the battery manufacturer of industrial long life deep cycle batteries for charging voltage recommendations, not the charge controller industry. The Charge controller industry does not warranty your batteries.