Electronic – Why do lead-acid batteries fail after about five years of operation

Charging lead-acid batteries with a power supply

Lead-acid batteries can be charged manually with a commercial power supply featuring voltage regulation and current limiting. Calculate the charge voltage according to the number of cells and desired voltage limit. Charging a 12-volt battery (6 cells) at a cell voltage limit of 2.40V, for example, would require a voltage setting of 14.40V.

The charge current for small lead-acid batteries should be set between 10% and 30% of the rated capacity (30% of a 2Ah battery would be 600mA). Larger batteries, such as those used in the automotive industry, are generally charged at lower current ratings. Cells constructed of a non-antimonial lead grid material allow higher charge currents but have a lower capacity. The cylindrical Cyclone is sealed and can sustain a pressure of up to 3.5 Bar (50 psi). A pressurized cell assists in the recombination of gases.

Observe the battery temperature, voltage and current during charge. Charge only at ambient temperatures and in a ventilated room. Once the battery is fully charged and the current has dropped to 3% of the rated current, the charge is completed. A good car battery will drop to about 40mA when fully charged; a bad battery may not fall below 100mA.

After full charge, remove the battery from the charger. If float charge is needed for operational readiness, lower the charge voltage to about 13.50V (2.25V/cell). Most chargers perform this function automatically. The float charge can be applied for an unlimited time.

--Information found here Hope This Helps!

Unlike surface vessels, submarines have to be able to sink. Every cubic foot of air space in a sub must be counterbalanced by almost 60 pounds of weight for a vessel to be able to submerge, and many submarines have a significant quantity of ballast for that purpose. Lead acid batteries have much less energy per unit mass than lithium-based batteries, but their energy per unit volume is pretty respectable (nb: something seems a little odd with that Wikipedia table; lead acid batteries weigh so much more than LiIon per unit volume that the difference in volumetric energy density should be much less than the difference in mass energy density). If one were to replace the batteries in a sub with magical batteries which stored the same energy and took up the same space, but weighed almost nothing, it would be necessary to add ballast to make up for the loss of weight (reducing the volume available for other purposes). It may well be that on some diesel subs, the batteries weighed more than ideal, and thus the weight of batteries was a limiting factor (rather than volume), but nuclear subs have much smaller stored-battery-energy requirements than diesels.

Also, lead acid batteries have more of a proven history of not going up in flames than do lithium-ion batteries. A submarine is not a good place to have things that may spectacularly catch fire.