Xantrex RV Series Inverter/Charger Owner’s Manual

Sealed Gel Cell

Another type of battery construction is the sealed gel cell. They don't use battery caps. The electrolyte is in the form of a gel (instead of a liquid) that allows the batteries to be mounted in any position without spilling. The advantages are no maintenance, long life (800 cycles claimed) and low self-discharge. The disadvantage is high initial cost and the possibility of damage from overcharging.

While there are many manufacturers of quality non-sealed batteries, there are only a few manufacturers of suitable gel cells. Don’t confuse sealed batteries with maintenance-free batteries—the latter is typically a standard liquid electrolyte-type battery without caps for adding water. When the electrolyte gets low you replace the battery.

AGM (absorbed glass mat) batteries are similar to gel cells and may be used in inverter applications.

Battery Care and Maintenance

If you have read the battery charger mode section of this manual, you already have a good idea of the stages of battery charging that combine to promote fast charging and ensure long battery life. Basically, there are five charger-related considerations to properly care for your batteries.

Charge Rate: The maximum safe charge rate is related to the size and type of your batteries. Standard vented lead acid batteries (with battery caps) can be charged at a high rate—equal to their capacity. Small batteries may require a lower charge rate. Check with the battery manufacturer. Using the optional RC7 remote control the CHARGE RATE setting may be adjusted to control the charging rate as a percentage of available charger output.

Bulk Voltage: This is the maximum voltage the batteries reach during the normal charging process. Gel cell batteries are charged to 14.2 volts, while non-sealed batteries are charged to 14.4 volts. Adjust the BATTERY TYPE setting to either gel cell or liquid lead.

Float Voltage: The batteries experience less gassing if they are maintained at a lower voltage than the voltage at which they are charged. The float voltage will automatically be adjusted when the proper battery type has been selected.

Temperature Compensation: Temperature affects the optimum voltage values for the bulk and float charging stages. The temperature probe automatically fine-tunes these voltages for you.

Typical BULK and FLOAT Setpoints for Common Battery Types (12 V System)

Battery Type

Bulk Volts

Float Volts

 

 

 

Gel Cell (sealed)

14.1 volts

13.5 volts

 

 

 

Lead Acid (non-sealed)

14.4 volts

13.4 volts

 

 

 

Monthly Maintenance

At the minimum, check the level of the electrolyte in each battery cell once a month. It should be above the top of the plates but not completely full. Most batteries have a plastic cup that the electrolyte should just touch when full. Don’t overfill the batteries or the electrolyte will spill out of the batteries when they are being charged. Only refill the batteries with distilled water. “Spring” water and regular tap water may have high levels of minerals, which can poison the battery chemistry and reduce battery life.

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