Max amp draw

BFL13 wrote:

pianotuna wrote:
PbO2+Pb+2H2SO4 -- ChargeDischarge -- 2PbSO4+2H2

BFL13,

If I am reading that chemical equation correctly Hydrogen is produced on discharge.

From;

https://www.sciencedirect.com/topics/engineering/sealed-battery

The link says the last part is "2H2O" not "2H2" but it is confusing.

My Battery Bible--

http://www.bestconverter.com/Books_c_67.html

just says that on discharge, " the hydrogen ions in the electrolyte move to the positive plates and combine with the oxygen to form water---"

on recharging, "the positively charged hydrogen ions are attracted to the negative plates where the hydrogen combines with the lead sulfate to form lead and sulfuric acid. When most of the lead sulfate is converted to lead, hydrogen bubbles form at the negative plates and rise through the electrolyte.....oxygen appears at the positive plate when this process is near completion. the formation of the gas indicates the battery is nearing complete charge..."

Those chemical equations are "generalized" to simplify the learning process. In reality, there are many other side reactions which occur, especially as batteries age and the plates/electrolyte becomes contaminated. (with sodium, potassium, magnesium, calcium, iron, fluoride, chloride, iodide, etc. from using other than distilled water) Generally, it's true that when recharging lead/acid batteries, more gas is generated than when discharging. The point is, if you are going to discharge wet cell batteries at a high rate over an extended period of time, eventually they will need to be recharged. (probably at a high rate also) The battery compartment(s) need adequate ventilation. That's my point! Overlook that and eventually, . . . . . . BOOM!

Chum lee