A typical deep cycle battery will discharge 45-75% of its capacity, although this figure can vary depending on the battery’s construction and the manufacturer. All deep cycle batteries require the use of an electronic charger. Deep Cycle Battery Charging and Maintenance Battery Temperature. In general terms, a battery requires more charging volts per cell when it is cold than it does when the battery is warm. Do not start using the battery that is charged below 12 volts! For a 12 volt liquid electrolyte battery at rest, a voltage of 13.2 -13.4 is normally appropriate; gel … Constant undercharging is the main reason for a deep cycle battery to lose its capacity very quickly. Charging a deep cycle battery does take time and it happens in stages. For a 12v lead acid this is typically 14.4 v (fast) and 13.8 (standard) and maybe 13.1 (maintainance.) That is not correct. The Float Voltage settings should hold the batteries at a level high enough to maintain a full charge, but not so high as to cause excessive "gassing" which will "boil off" electrolyte. The voltage needed to charge a discharged battery also changes as a function of temperature. You really want a 3 stage charger. State of charge, or conversely, the depth of discharge (DOD) can be determined by measuring the voltage and/or the specific gravity of the acid with a hydrometer.This will NOT tell you how good (capacity in AH) the battery condition is - only a sustained load test can do that.Voltage on a fully charged battery will read 2.12 to 2.15 volts per cell, or 12.7 volts for a 12 volt battery. If your battery charge is below 12 volts, there is a big chance that it is not fully charged yet! While it is possible to cycle the battery down to 20%, it is considered best practice to keep the average cycle at around 45% to maximize the lifespan of the battery. Sulfation is the natural byproduct when the battery discharged. The electronic charger monitors the voltage and current fed to the battery. Charging Motorcycle Batteries A fully-charged 12-volt motorcycle battery should measure about 12.6 - 13.5 volts between terminals depending upon its chemistry. 10.5V is a destroyed battery for a normal (not deep-cycle) automotive battery. A healthy deep cycle battery with a rating of 12V shows a multimeter reading of more than 12.4V and a 6-volt battery will at least get a reading of … Many deep cycle batteries are sealed, so no monitoring of the fluid level is possible. If the battery is fully charged (according to the battery charger) but the voltage is 12.5 or less, the battery is sulfated. Cell voltage for a fully charged batter is approximately 2.12V for a total of 12.7V A trickle charger is a poor way to charge a battery. Running cars have alternator voltage regulators set between 13.5 and 16V. Cycles are the number of times the battery moves from full discharge to full charge. In a car 12V is dead, a “12V” lead-acid battery should be above 12.5V at rest. If you had a true deep discharge battery like a Trojan battery, their recommended charge rate is betwen 10-13% of its 20 hour capacity. You have to apply a voltage that is higher than the battery voltage in order to get it to charge. If you know how much power your application takes to run, and the time you would like to run it, we'll recommend a 12 volt battery with a safe amount of AH (Amp Hours) that will give you the runtime you need. Typically, a fully charged deep cycle battery will have a voltage of over 12.8V - 13V. This calculator is designed to help you find a deep cycle battery when a continuous load is applied, not for cranking or starting purposes. This charge graphic relates to 12V AGM deep cycle batteries, but can also be used as a general guide for other battery types though keep in mind that there may be slight differences in the voltage rating. Naturally, charging the battery back up will reverse the sulfation crystals and turn it back into electrolyte, ready to produce power again.