Ⅰ. What are the types and uses of marine batteries?

Boat batteries can be divided into two categories: Acid and Alkali, and the capacity is generally measured by the 10-hour discharge rate (ampere-hour). It is used as a backup and emergency power source on the ship, mainly as a power source for emergency lighting, telephone, alarm system, radio equipment, electronic chart, etc., and is used to start emergency generators, lifeboats, rescue boats, etc.
But now there are maintenance-free batteries, which can be replaced directly at the specified time. When replacing batteries, keep records.

Ⅱ. How to maintain and manage the marine battery?

2.1. Keep the surface of the battery clean, and screw the liquid injection hole plug tightly to prevent the electrolyte from escaping due to boat shaking.
2.2. Ensure reliable conductivity, pay attention to whether the battery’s pole chuck is corroded or oxidized (apply some petroleum jelly), and tighten the screw of the wire chuck.
2.3. Check regularly that the battery voltage and the specific gravity of the electrolyte meet the requirements. Pay attention to checking the height of the electrolyte and the presence of precipitates, and replenish distilled water in time (do not add dilute sulphuric acid at will).
2.4. The battery should avoid long-term under-charging and over-discharging, etc., to prevent the sulphation of the pole plate (i.e. aging) leading to battery damage or performance decline (meaning that the voltage will soon be sufficient and will soon decline). To keep the battery performance good should be regularly strong charging and full capacity discharge so that the electro-hydraulic material gets full and even activity. The current and temperature during charging should not be too high, otherwise, it will lead to deformation of the pole plate or damage to the container breaking intensity.
2.5. The battery which often does not carry a load should be charged and discharged once a month (generally only 50% of the capacity and recharge immediately).
2.6. Do not mix old and new batteries.

Ⅲ. How to judge the lead acid battery charging good or bad?

3.1. Judging by cell voltage: the cell voltage reaches the required value at the end of charging and does not change for a long time.
3.2. Judging by measuring the specific gravity of the electrolyte: the specific gravity of the electrolyte reaches the required value at the end of charging and does not change for a long time.
3.3. Uniform bubbles up and down the pole plate, electrolyte turns slightly clearer from milky white.
3.3. A large number of bubbles are generated.
Fourth, what is meant by the capacity of the battery and the factors affecting the capacity of the battery
The capacity of the battery is the storage capacity of the battery. Take the acid battery as an example, it means a fully charged battery with continuous discharge, from the beginning until the end of the discharge of the total current and the product of time. The rated capacity of a battery means that it can be discharged for 10 hours at a certain temperature at a value of 1/10th of the capacity in terms of current amperage.
Factors affecting the capacity of the battery: electrolyte concentration, temperature, discharge current, and natural discharge time.

V. What safety matters should be noted when using marine batteries?

As hydrogen gas is released when charging, the venting holes on the battery should not be blocked, the battery room should be pre-ventilated, smoke and fire should be banned, and metal tools should be prevented from falling on both poles of the battery to cause a short circuit, and electrolyte should not be splashed on eyes, skin or clothes. It is also best not to wipe the battery with a dry chemical fiber cloth to prevent electrostatic fires or explosions.