Gel Battery
A type of sealed lead-acid battery in which the electrolyte is gelled with silica into a solid consistency. It is known for its leak-proof construction and good resistance to deep discharge; on the other hand it is more sensitive to charge voltage than AGM and its ability to deliver high current is more limited.
Because the electrolyte does not move in a gel structure, stratification does not occur and the battery can work in any orientation. The gas channels within the gel mass let the gas formed during charging recombine at the plates. If these channels are destroyed by overvoltage, the damage is permanent.
On the charging side the absorption voltage of a gel battery is typically held below that of AGM, of the order of 14.1–14.4 V; float is around 13.5 V. The exact values vary by manufacturer and the gel profile must be selected on your charger. Charging with a lead-acid profile dries the gel out and permanently reduces the capacity.
The internal resistance of a gel battery is higher than that of AGM; this means the voltage drops a little more under loads that draw high instantaneous current. This difference can be felt during the short peak currents when the levelling jacks operate. Long-duration low-current loads and deep-cycle-oriented use, on the other hand, are the scenario in which a gel battery is strong.
Context in which this term is used: RV automatic levelling guide