The lead batteries are the most economical investment at the delivery time of the system.
Unfortunately, these batteries are susceptible to misuse and have various disadvantages which need to
conduct further research, especially to improve their life cycling (charging and discharging). It is in
the best case, about of a thousand cycles (approximately 3 years), which is very insufficient in
production systems whose lifetime is about 15 to 20 years. Moreover, the "sudden death" of lead
batteries in end of life is hardly compatible with the requirements of reliable power in remote locations.
Alkaline batteries (Ni/Cd and Ni/MH) are much more efficient, robust but more costly. They are better
adapted to low temperatures and used where high reliability is required. By cons, the Ni/Cd suffers,
according to the method of use, from a "memory effect" which reduces the usable capacity.
Technically, lithium batteries have the best performance. Indeed, self-discharge of Li/ion is low and
their stored energy density is much higher. They also allow a cycling at high deep of discharge with
less impact on performance compared to the nickel/cadmium and lead batteries especially. Primarily
for cost reasons, these batteries are still quite uncommon.
Finally, when the batteries are not recycled, they are a major source of pollution. For all these reasons,
the batteries will not be adopted for wind-diesel hybrid system (WDHS)