First of all, Kendrick does not use deep-cycle marine batteries (hereinafter referred to as DCB) in our products, but many of our customers use them on site.

　　Some customers who use DCB ask us to lower (or disable) the low-pressure cut-off (LVC) of the dew heater controller so that they can have a deeper understanding of the cycle of these batteries. Some people complain that the LVC function cuts in prematurely because of its battery type. There is a belief that there is no harm in reducing the DCB below the 11.6-volt cut-off function of the controller.

　　The fact is that any lead-acid battery, whether it is a gel battery, a Sealed AGM Battery, or a fully charged battery (such as a DCB), should be cut off at 11.6 volts. Otherwise, it will increase the risk of damaging the battery. If it is charged sufficiently deep into the battery, the battery will be damaged. Having said that, the absolute minimum voltage that a lead-acid battery can discharge under load is 10.8 volts, but this is not recommended (for more information on this, see below).

　　There is a false belief among many people that only because DCB is a "deep cycle" battery can it be deeply brought into its charging cycle. This is not true. The real meaning of "deep circulation" is the availability of current when higher amperage is required. It is much easier for users of deep cycle batteries to draw higher current from DCB (ie when starting the motor) compared to using gel batteries or AGMs. Under the amperage used by amateur astronomers, the discharge curves of these batteries are actually the same, and they should all be cut off at 11.6 volts to maintain the long-term viability of the battery in question. The only advantage of deep-cycle batteries is that they tend to be used in larger ampere-hour configurations compared to AGM or gel batteries.

　　Also, it is important to note that Sealed Deep Cycle Battery does require regular maintenance, while AGM and gel batteries do not. DCB should be tested with a hydrometer every week to ensure that the specific gravity of the battery is 12.85, and the battery must be checked regularly to maintain the liquid level in the battery. In situations where the use of high-current batteries is important and the batteries can be transported safely without allowing acidic electrolytes to overflow from the batteries, deep-cycle batteries are meaningful. In any other case, AGM or gel batteries will be the batteries of choice. Kendrick uses non-sprinkling AGM in our power plant.

　　The last and very important point is that when any lead-acid battery (regardless of its type) falls below its safe useable voltage (11.6 volts), the amperage will increase to keep up with the power requirements of the equipment used.

　　For example, suppose your system requires 50 watts of power and is using a Sealed Deep Cycle Battery. At 12 volts DC, to produce 50 watts, you will need more than 4.1 amperes of current. If you lower the DCB to 6 volts and still need 50 watts of power, you will now force the battery to output 8.33 amps. Double the amperage! In this case, even if you still consume only 50 watts, these extra ampere currents will still destroy the fine copper traces on the circuit board and the transistors, diodes, and ICs in many electronic devices used by amateur astronomers, especially astronomical imaging. The instrument is there. Beware!

　　If you value electronic products and batteries, please do not use a DC-to-DC converter to bypass the low-voltage cut-off function of the dew controller, which will increase the voltage from less than 11.6V DC to 12V DC.

　　During shutdown

　　Anyone whose battery seems to be cut off prematurely can be damaged by too deep discharge (or even one time), damaged by improper electrolyte maintenance, or the battery is old and beyond repair. A battery that is regularly discharged to 10.8 volts and then recharged is expected to get 354 charge cycles from the battery. A battery that is regularly discharged to 11.6 volts and then recharged is expected to obtain a charge of 900 to 1000 from the battery. A properly maintained battery can last for many years.

　　If you value electronic products and batteries, please do not use a DC-to-DC converter to bypass the low-voltage cut-off function of the dew controller, which will increase the voltage from less than 11.6V DC to 12V DC.