Quote:
Originally Posted by Tech Support
I was always taught that the gentler you pump the current in, the better for the batteries.
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That is not quite accurate and leaves to much guess work to know what gentle means.
As a generic rule no more than the C/8 rate which means the battery 20 hour amp hour rating divided by 8. So for a Trojan T-105 with a 225 AH rating = 225/8 = 28 amps is the highest current you want to supply and will fully charge the a completely dead battery in theory in about 10 hours for 5 hours for a 50% DOD.
Ideally the seat spot is from the C/10 to C/14 rate. This is why you see most cart battery chargers in the 25 to 16 amp range. There are two reasons for this:
1. is a condition of stratification. Stratification is where the heavier component of the electrolyte (sulfuric acid) will settle to the bottom of the battery leaving the lighter water on top which accelerates the formation of lead sulfate crystals on the battery plates. Lead Sulfate crystals are the death of batteries and the main cause of 90% of all battery failures. The higher charge rates literally cause a slight boiling action and mix up the electrolyte preventing or correcting stratification.
2. As mentioned above Lead Sulfate crystals is the death of batteries. The soft crystal formation start to form when the specific drops below 1.250 or roughly at 10% DOD. and if left for extended period of times will harden on the plates. Below 50% DOD and the crystals harden, and once they turn hard there is no way to remove them. Ok at a higher charge rate of C/8 to C/12 if you allow the voltage to rise to the Bulk charge voltage of around 2.45 volts per cell the soft crystals are disolved back into the electrolyte and all is well. If they are allowed to harden, there is no return.