What's the story about batteries?

Battery technology has changed over the years - batteries have become greener, they last longer and they can be charged more often. 

But how do they stack up against the older Lead Acid Batteries that we still use in our cars.

Lithium Ion

Advantages

1. Last around 3 years
2. Can be charged 500 to 1,200 times
3. Can withstand deep discharge
4. Lighter than LAB

Disadvantages

1. Very expensive - more expensive than many e-bike kits
2. Do not like to be trickle charged
3. Charger must be switched off immediately after charging is completed

Lead Acid

Advantages

1. Cheaper that Lithium batteries - cost as little as R900 -R1,400
   
2. Simpler technology
   
3. Easier to replace - can easily build your own
   
4. Cheaper to replace (but more often)
   
5. Can be trickle charged

Disadvantages

1. Do not like being deep discharged
2. Heavy - more than double the weight of Lithium Ion
   
3. Last about a year
   
4. Will take around 300 recharges
   
5. Disposal not green
   

Despite what has been said above, one needs to take figures quoted about numbers of recharges and battery longevity that are quoted by manufacturers and some retailers with a pinch of salt.  Many quoted figures are based on ideal situations.  


In reality, however, battery life and usability is depends on many factors including, to mention just a few:

• temperature - lithium batteries are sensitive to temperature
• extent of discharge - lead acid batteries in particular, do not like deep discharge
  
• battery age
• amount of time battery is charged - ideally a battery should be disconnected from the charger as soon as it is fully charged

Why are the Lithium batteries so expensive?

The batteries are expensive for a number of reasons:

Firstly, they are made up of lots of lithium battery cells - anywhere from 35 to 60, depending on the battery's voltage and capacity (Ah).  And each cell is expensive - each cell retails for between R80 and R155, depending on the make.
 
Secondly, there is the Battery Management System (BMS) - this is a computer controller that comes packaged inside each battery - it manages the charging and discharging of the battery cells to ensure that they do not

• charge evenly across the cells and thus do not overheat when charging 
• discharge evenly across the cells

Failure of the BMS can result in the battery catching fire or exploding if it is left to charge after it has reached its charge capacity - this is why we advise you to disconnect the battery from the charger once it is fully charged.

Thirdly, building the batteries is labour intensive.  The cells have to be connected and spot welded, first in series to establish the voltage and then in parallel to create the capacity (Ah).  Then the cells have to be connected to the Battery Management System which in turn has to be connected to the test lights, to the charging port and to the battery connectors.

But mostly, as mentioned above, each battery cell is very very expensive!

Tips on looking after your battery

1. Store in a cool place
2. Store the battery at 50% charge if you're not riding your bike for extended periods.  Storing a fully charged battery will negatively affect the batteries capacity.
   

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