Gel Cell Battery Charging Voltage

Battery voltage state of charge table.

Gel cell battery charging voltage.

Turn on the charger and charge the battery at a constant voltage of 2 25 to 2 30 volts per cell 13 5 to 13 8 volts on a 12 volt battery at 58 degrees fahrenheit 20 degrees celsius. At this voltage the battery should regulate its own level of current. This is probably the most sensitive cell in terms of adverse reactions to over voltage charging. The table below shows the voltage and approximate state of charge for each type of battery.

Note that if you charge your gel battery on agm charging settings you will eventually damage the battery. Most battery manufacturers recommend sizing the charger at about 25 of the battery capacity ah amp. The peak charging voltage for gel batteries is 14 1 or 14 4 volts which is lower than a wet or agm type battery needs for a full charge. The modern gel or vrla battery was invented by otto jache of sonnenschein in 1957.

The battery is then held at this voltage until the charging current drops to a value of 0 01 x c amps where c is the battery s amp hour rating. The electrolyte in a gel cell battery has a silica additive that causes it to set up or stiffen. The first agm cell was the cyclon patented by gates rubber corporation in 1972 and now produced by enersys. The first lead acid gel battery was invented by elektrotechnische fabrik sonneberg in 1934.

Exceeding this voltage in a gel battery can cause bubbles in the electrolyte gel and permanent damage. When attempting to charge a gel battery with a lead acid charger you must ensure the peak charging voltage does not exceed 14 7 volts which would result in dried non conductive gel. In this mode the battery is charged with a fixed charging voltage until the terminal voltage reaches 2 40 to 2 45 volts per cell 14 4 to 14 7 volts for a 12 volt battery at 20 c. State of charge does vary a little between a sealed lead acid flooded gel and agm deep cycle battery types and also between brands.

The recharge voltages on this type of cell are lower than the other styles of lead acid battery. Even the weather can play a role.