Facts About Lithium Vs. Lead Acid Batteries
Amp Hours converted to Watt Hours
How to Calculate E-Bike Range
Lead, which is the heaviest non-radioactive metal, has been the standard in batteries for decades. Why should you consider a lithium battery conversion? Here are seven features explaining the disparity between lead acid and lithium-ion batteries.
1) Weight: Lithium-ion batteries are one-third the weight of lead acid batteries.
2) Efficiency: Lithium-ion batteries
are nearly 100% efficient in both charge and discharge, allowing for
the same amp hours both in and out. Lead acid batteries’ inefficiency
leads to a loss of 15 amps while charging and rapid discharging drops
voltage quickly and reduces the batteries’ capacity.
3) Discharge: Lithium-ion batteries
are discharged 100% versus less than 80% for lead acid. Most lead acid
batteries do not recommend more than 50% depth of discharge.
4) Cycle Life: Lithium-ion batteries cycle 5000 time or more
compared to just 400-500 cycles in lead acid. Cycle life is greatly
affected by higher levels of discharge in lead acid, versus only
slightly affected in lithium-ion batteries.
5) Voltage: Lithium-ion batteries maintain their
voltage throughout the entire discharge cycle. This allows for greater
and longer-lasting efficiency of electrical components. Lead acid
voltage drops consistently throughout the discharge cycle.
6) Cost: Lithium-ion batteries are higher upfront in cost but the true cost of ownership is far less than lead
acid when considering life span and performance.
7) Environmental Impact: Lithium-ion batteries are a much cleaner technology and are safer for the environment.
Though they are used to power the same applications, that is where the similarity between lithium-ion and lead acid batteries ends. Lithium batteries deliver higher-quality performance in a safer, longer-lasting package.
Amp Hours converted to Watt Hours
Formula is (Ah)*(V) = (Wh). For example, if you have a 10
Ah battery rated at 48 V, the power is 10Ah * 48V = 480Wh. Convert Watt
hour to Amp hour (Wh to Ah).
How to Calculate E-Bike Range
Watt hours is a way to measure the energy capacity of a battery pack,
so you know what to expect from your new E-bike in terms of range
performance. To calculate the watt hours (WH) of a battery pack, simply
multiply the voltage by the amp hours (Ah) of the pack. A 36-volt 10-Ah
battery pack has 360 watt hours (36 X 10 = 360). If you are nitty with
your energy usage, each mile you travel will cost you about 20 watt
hours. Therefore a 360 watt hour pack will get you about 18 miles. The
range can vary widely depending on where and how you ride.
Watt hours determine the range of your bike, the cost of your bike,
and the weight of your bike….three very important factors to consider
when buying an electric bike.
Batteries come in different cell qualities. Name brand cells such as
Samsung, Panasonic and A123 will last longer (number of charge cycles)
than no-name Chinese cells. Of course if your pack consists of name
brand cells, the cost per watt hour will be much higher.
A 250 watt motor will burn 250 watt hours in an hour and will last
you an hour and 20 minutes at full throttle on those 360 watt hours, but
it will not provide you with very much assist.
A 500 watt motor will burn through the same pack at full throttle in
less than 45 minutes, but you will be given twice as much assist as you
get from the 250 watt motor. If you are nitty with your 500 watt motor
and run it at half throttle (250 watts) and pedal a lot, you will get
the same efficiency as you get with a 250 watt motor. However the
exhilaration of available electric power is sometimes hard to resist.
36V 9Ah = 14 Miles
36V 12Ah = 22 Miles
48V 10Ah = 24 Miles
48V 17.5Ah = 42 Miles
48V 20Ah = 48 Miles