Battery is the power source which provides electric power to the motor, and the motor finally drives the electric vehicle. Taking lead acid battery for example, before we come into any conclusion, we shall make clear of the major differences between them:
The lead acid batteries are mainly divided into of VRLA and tubular lead acid batteries. Both of them are of big volume, heavy weight, low energy density, and are using lead and sulphuric acid as major chemicals to store electric energy. The main difference between VRLA battery and tubular battery are:
A. VRLA is sealed maintenance free type, requiring no maintenance during charging and discharging; while tubular battery shall be maintained from time to time by adding distilled water and removing lead sulphate materials on the poles. Improper or irregular maintenance might lead to reduction in battery life.
B. With the same battery power, the VRLA battery is having around 5% – 10% more discharging depth rate(DOD) than tubular battery, thus it can contain more electric powder.
C. The tubular battery can withstand bigger instant current thus is more frequently used as engine starter, while VRLA battery can provide longer endurance(continuously smooth discharging).
D. The Min power for VRLA battery is normally 12V12ah/piece, size: 150mm(L) x 100mm(W) x 100mm(H), weight: 4Kg; while the Min power for tubular battery is normally 12V60ah/piece, size: 260mm(L) x 175mm(W) x 200mm(H), weight: 20Kg(the availabilities are subjected to different supplying markets in different regions).
E. SOC(state of charge) degradation. After about 300 times of full cycles(one cycle = one charging and one discharging) the applicable SOC of a VRLA battery might drop to 30% of its original full SOC; while such number of full cycles for tubular battery is about 150 ~ 200.
F. Comparing with tubular battery, VRLA battery has much lower self-discharging rate. Due to this, during normal storage, the VRLA battery shall only be fully charged for every 3 months and kept in shady and cool environment; while tubular battery shall be fully charged for every 1 month.
Based on the above differences between both batteries, it is suggested that:
The VRLA battery is highly used in electric scooters, as well as the electric tricycle vehicles due to its characters of maintenance free, compact size and bigger life cycles, in case the customers are not that cost sensitive.
The tubular battery is mainly used in two regions, one is for engine ignition(starter), the other is for three and four wheeled vehicles(such as heavy duty cargo tricycle, E golf car, E garbage vehicle) which transport heavy goods, considering that the customer is also cost sensitive.
However, the tubular battery is more and more replaced by high power VRLA battery in the heavy-duty and large-sized vehicle, due to its significant advantages.
Additional tip: Lead acid battery is sensitive to the temperature, the cold weather(minus 0 or even lower) will largely reduce the chemical activeness thus the battery applicable SOC will be reduced more than half. In cold region the MnNiCo Ternary Li-ion battery will be a perfect solution.
By Roger Sun
Mar 7th 2020
Post time: Mar-09-2020