REV-Bike Batteries

Different Types of Batteries

Most modern electric bike utilise Lithium battery technology, though there are a lot of different chemistries under the title of Lithium-Ion (which only tells you the format of the battery, not the chemistry).  Many different chemistries exist, with some having much shorter lifespans than others.  If you are not being told the chemistry other than Lithium Ion, you can presume these as cheaper chemistries which will have short lifespans. Replacement costs are high, so this is definately an important factor in choosing your battery.

The most highly regarded lithium chemistries for E-bikes and Electric Car applications currently are:

1. Lithium Iron Phosphate, or LiFePO4.  These packs are reliable and long-lasting (about 1000 charge cycles is realistic), but heavy (about 7.5kg for 36v 12ah)

2. Lithium Tri-Metal or 'NMC' (Lithium Nickel Cobalt Manganese Oxide).  These packs are much lighter (about 4kg for 36v 12ah), but don't last quite so long (about 600 charge cycles normally), depending on charging and dischanrging habits.  

Most electric cars are using NMC now, as are we (though our LoVo packs are special compared to others, see below for details), using LG, Panasonic or Samsung cells.  

Find out more at Battery University.  

 

Battery Management Systems

Lithium batteries all have a BMS onboard, which balances the charge between the cells when the pack is almost finished charging, and prevents over-charging and discharging.  These circuit boards can limit the current too, so they need to be well matched to the motor you are using.  

 

Battery Care & Prolonging Lifespan

There are several important factors which determine how long your pack will last.  Here are a few Golden Rules which are helpful to remember:
1.    Always turn the battery/motor OFF when you are not using it (like locking your car when you get out)
2.    Charge up your battery as often as possible, avoid running right down to empty 
3.    Keep it out of extreme heat (over 30 degrees) or cold (below 5 degrees)
4.    If not using for a while, store at half charged.

Yet our new LoVo packs are not the same as others..

After significant R&D, we now have special BMS and charging set-ups onboard our LoVo packs, which should mean they get a lifespan better than even the LiFePO4 packs.  Through charging to a slightly lower voltage (4.1v per cell rather than 4.2v), there is less stress on the cells, so they should last twice as long.  This can be improved further by raising the low-voltage cutout level on your controller, so the cells don't get as close to empty.  We offer FREE EXTENDED WARRANTY of 2 years on these packs!

See our detailed Battery Care Guidelines for more details.

 

Lithium Batteries are bad for the environment, how do you deal with this?

Yes, electric bikes are much better for the environment than cars, but they have their draw-backs too.  We strongly encourage use of LiFePo4 or LiNMC batteries due to their longer lifespan.  We also promote recycling batteries through an EPA accredited company such as MRI Pty Ltd (with current technologies 98% of the contents of a Lithium battery can be recycled and avoid landfill). The cost of battery recycling is approx $20 for our batteries.  You may get away with taking your old battery to Officeworks or somewhere else, who receive batteries for recycling / safe disposal.
We provide detailed information on battery maintenance, so our customers can get the most from their batteries, and reduce the need for premature replacement.  We also reuse some tired cells for other home energy projects, such as solar powered garden lighting.

Working out Range:

In addition to the 'amp hour' storage capacity of your battery, the distance you will get depends on a lot of factors, such as how much you are pedalling, how hilly the terrain is, how many stop/starts you are doing, the weight of you & the bike, the pressure in your tires, the age of the battery, and the temperature of the battery.  To get the most distance, you should pedal as well, keep your tires nice and full of air, keep the battery as temperate as possible, avoid stop-starts, and use the regen braking (if you have it) to recharge your battery (see the Motor page for more details).

To get an idea of the time you can ride for on a charge, we can do some basic electrical maths.. 
Volts X AmpHours = WattHours. 
So, a 36v 10ah battery should give 360 watt hours, and if you are riding at 200watts, this will last for under 2 hours.  Keep in mind there will also be some left-over power that the battery won’t use, to preserve itself.  So you might want to presume about 1.5hours of riding without pedalling.  If we presume we are applying an equal amount of power as the motor through pedalling, we can double this, which should get the average person about 3 hours per charge, or somewhere around 60kms at an average speed of 20km/h (on the flat).
These figures can only be a guide, as hills create huge variations, as does starting and stopping frequently.

General rule is:  Voltage X AmpHour of battery, divided by 6-10 = expected kms.

Another rule used is:  AH capacity / Average Amps drawn X Speed (km/h) X 0.8 (80% efficiency) = expected kms

(Average Amps is 7amp for 250w systems, 10amp for 500w systems, and 15amp for 1000w systems)

Our estimates around distance on the various kits (with pedalling, on fairly flat terrain) are as follows:
Zoom Kit (200w, 36v10ah) = 40-60kms, Smart Kit (500w, 48v10ah) = 40-60kms), Grunt Kit (1000w, 48v10ah) = 30-50kms

Can I Solar Charge the battery?

Yes.  If you are familiar with this level of electrionics, you could set up your own solar charging system.  These can charge your battery practically anywhere with direct sunlight.  Solar panels must have a regulator attached to ensure the voltage doesn’t vary too much for the BMS to manage, and so you simply plug the battery into the regulator.  Cost-free and zero-carbon charging is achievable, meaning truly sustainable individual transport is here!  Mount the solar panel at home or at work / school, so you can charge your battery wherever you are while the sun is shining.

Batteries should not be charged and discharged at the same time, so if you want to mount a solar panel on your bike/trike/trailer, you would need a spare battery which will be charging, as you are riding using another battery.
Keeping your battery out of the sun is an important part of solar charging, as you will damage the battery if it is in the direct sun for prolonged periods.

We recommend speaking to Matt at SolarBike in Perth if you are looking for a solar charging setup.

 

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