New batteries should be charged before they are installed. Specific Gravity should be 1.260.
New batteries will only reach full capacity after 20-50 cycles.
Vent caps should be tight and in place when charging batteries.
Batteries should be watered after charging. Keep the acid level 0.5 cms below the fill well of the cover. Be careful with water used to top up, particularly if water has iron dissolved. Use distilled or treated water not to exceed 200 TDS (total dissolved solids)
Battery chargers should be matched to fully charge batteries in an 8-hour period.
Avoid charging at temperatures above 40 degrees centigrade.
Deep cycle batteries in a bank must be equalized periodically. Equalizing is extended low current charge after a normal charge cycle. Charge for 3 amps for an additional 3-4 hours. Deep cycle batteries in active daily charge cycles should be equalized once per week.
Ensure batteries are always bought back to full charge immediately after use. Operating or storing in a partially charged condition will shorten life and reduce capacity.
Always match chargers. An undersized charger will never do the job, an oversized charger will cause excessive gassing and heat, which will damage plates.
As batteries age, their maintenance requirements change. They need longer charging time, and higher finishing charge rates, more watering, and capacity decreases.
If batteries are in a battery bank, do not place a new battery in a bank that has had more than (say) 50 cycles. Either replace all with new, or use a good second hand battery.
Inactivity can harm batteries. If seasonal use is planned, completely charge battery, store in a cool place, boost charge every 2-3 months.
Battery testing is an important preventive maintenance procedure. Hydrometer reading of a fully charged battery gives an indication of the true charge level. Voltage checks can locate an open circuit or faulty battery. A weak battery in a series or parallel situation will cause premature failure of companion batteries.