Types of Dry Cell
Zinc Carbon - The typical cheap torch cell battery and liable to leak when old.
Alkaline - Can supply a large current and holds up to three times as much as zinc-carbon cells. it has a low leakage rate and is often used in torches, radios and recorders.
Zinc Chloride - This can supply a large current and holds more than a zinc-carbon cell. This also has a low leakage rate.
Silver Oxide - Low power but long lasting. Usually made as button cells for watches and calculators.
Mercury Oxide - This is similar to silver oxide and used in hearing aids.
Li-ion - These batteries deliver low currents for a long time or a high current for a short time. HiGH CURRENTS FOR A LONG TIME CAN LEAD TO A BATTERY MELTDOWN. They store about three times as much as alkaline cells and remain in working condition for about 10 years. They are expensive. They are usually used as a backup supply for computer memory and research is looking into making flexible cells that can fit into any oddly shaped space in portable equipment.
Zinc Air - These cells offer very high power in small size and are often used in laptop computers.

Types of Rechargeable Cell
Lithium Polymer (Li-po) - These batteries deliver low currents for a long time or a high current for a short time. HiGH CURRENTS FOR A LONG TIME CAN LEAD TO A BATTERY MELTDOWN. They store about three times as much as alkaline cells and remain in working condition for about 10 years. They are expensive. They are usually used as a backup supply for computer memory and research is looking into making flexible cells that can fit into any oddly shaped space in portable equipment.
Nickel metal-hydride (NiMH) - This type has several advantages over the NiCad battery. One advantage is that it is able to hold 30 to 50% more energy. They do not have the 'memory effect' which means it can be recharged without the need for discharging.
Nickel-cadmium (NiCad) - These cells store less charge than zinc-carbon cells but can deliver a high current. NiCad batteries exhibit the memory effect so it is necessary to discharge them before recharging. if this does not happen the stop delivering current once the 'remembered' level is reached.
Lead-acid (Pb) - These batteries are great for high load applications, whether it be charge or discharge. They are very heavy and often used as car batteries.