“If you keep a battery topped off for a month or two before you use it, such as a trolling motor battery, which frequently doesn’t get used for long periods of time, will this stratification occur? I mean the battery will be staying 95 to 99% charge for long periods.”
Short answer.. Yes..
The internal resistance of the battery stays high because it’s not being discharged and it doesn’t draw much current. This allows the voltage to rise to the float voltage level of the charger easily and quickly, which doesn’t create many bubbles. The bubbles is what mixes the electrolyte..
Most float chargers (A.C. Type) only allow the charge voltage to go maybe to ~ 13.2-13.4 volts max so the battery doesn’t boil to death. Hence, no mixing..
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