There are two primary types of batteries used in an electric bike or scooter. These are Lithium-ion, and Lead-acid.
I will guide you through the pros and cons of both types as we roll down the road together.
Lead acid batteries – Old or good enough?
Originally designed in the mid 1800s, Lead acid types are not the most efficient. Even if you only use 30% battery, the primary charge has been drained and this will affect the output when doing long distance trips. This is called DoD (Depth of discharge). Now because of this discharge, there is less power. Instruments the bike uses may struggle or fail to operate if you deplete 50% and do not charge the bike a full cycle before the next ride, These batteries also take much longer to charge, usually 5 – 8 hours for all lead acid types at 2 amps.
A lead acid battery can provide between 200 – 500 charging cycles if you keep the DoD at a maximum of 55% per ride and always fully charge the battery right after use. If you dip deeper into the battery’s charge, you are draining it out and will likely have to replace it in a short time. An easy way to remember this is to not crank the throttle and take it easy on the bike. Like a person for example, we can jog a much further distance than what we would accomplish by sprinting. We would be exhausted and have to rest (or charge) for a while before we can go at it again. Excessive use will result in premature aging and can leave you stranded in an intersection (from personal experience).
The traditional lead acid battery is a more widely available, affordable and efficient option good enough to get you started, but it does not compare to a more advanced and reliable Lithium-ion battery, which we will discuss next!
Lithium ion batteries – High efficiency & performance
There was the original lithium-cobalt-oxide (LiCoO2) battery in the 1980s, but was unstable and caught fire if overcharged. About a decade later a new recipe of lithium-iron-phosphate (LiFePO4) proved to be much safer and efficient than its older brother. Now that you understand the basics of how an electric bike battery works, lets break down the advantages of the lithium ion battery:
- Superior chemistry provides longer battery life expectancy.
- Can deliver 2000 – 5000 charge cycles, even when pushing DoD to 80% (Can vary depending on max speed setting).
- Does not prematurely age if you don’t charge it right away (Still recommended to prolong battery life).
- Highly efficient charging – this can be 100% charged in 30 minutes instead of up to 8 hours with a higher amp charger.
- Weight and size dimensions are 50% lighter / smaller than a lead acid battery.
- BMS system (Battery Maintanance System)
This is ideal if you want a scooter or motorcycle that seats two people to carry up steep hills and rough terrain. Compared to a lead acid, it is still a better performer on a charge low as 20%. All batteries last longer if the effort is made to keep the battery charged after each use but with lithium, you can leave the worries of an undercharged battery behind. These 3 variables should be considered like a lead acid battery for optimal performance and experience:
- Range and performance will change for each individual (Weight, height, throttle control etc).
- If excessively drained and charging is neglected, this will shorten battery life expectancy.
- General maintenance and cleaning will make repair work easier.
If you want to upgrade from a lead acid to lithium, have a specialist inspect the controls on your bike to make sure it can handle higher currents. There is no such thing as being too careful when it comes to the well-being of your bike but better yet yourself.
– Lead Acid –
- Very cheap and can be found in many local stores. Usually up to $90 each x6 cells for around $700 after taxes. This can change depending on the brand but not by much.
- SLA lead acid cells put out higher current, with a trade off of price for pound. Can cost from $100 to $150 and because of higher output, can use fewer cells than the regular lead acid.
I ride my bike up to 3 times a week with the regular type. After 4 months with an overpowered / factory defective governor, I had to replace these batteries. I was still in the warranty period so I dodged a $750 bill (including labor). If you have a bike that comes properly assembled and no faulty parts, your batteries will last at least another 6 months longer than mine did if you take good care of them.
– Lithium Ion –
- 3 times the price. $350 – $500 each x4 high density lithium cells will run up to at least $1500 to $2000.
- Not as readily available like lead acid, but this is improving with increasing demand and popularity.
- Needs little to no maintenance to maintain maximum life span.
- Easier to replace or install onto most electric bikes. Again make sure to check your bike, it may need modifications!
Your electric bike should always come with its own charger. For lead acid batteries, they will take a long time to charge (5 – 8 hours). With lithium batteries, the regular charger will charge the battery much faster (up to 2 hours). But when using a fast charger, your bike can be charged even faster, in little as 30 minutes. It is dangerous to fast-charge a lead acid battery and can be the same with lithium if your battery is not designed to handle higher amps. In another post I will break down the math of power vs time when it comes to charging, and riding abroad.
You will have fun no matter what!
With all things considered, it comes down to you. If you only want to ride once a week for small cruises, a lead acid battery will last you a long time and will be cheaper to replace when required. For high performance, quality and overall convenient lightweight to maximize range and overall reliability, the lithium ion battery is the best option.