EXTREME POWER LITHIUM BATTERIES
We have been importing various Lithium battery cells for almost 10 years now, dealing with various types of cell from Lithium Polymer, LifePO4, Lithium-NiCoMn (nickel cobalt manganese), and Lithium-Mn2O4 (Lithium manganese dioxide).
While there are many types of Lithium chemistry available now, the quality of the cell production has a huge factor on lifespan and maintenance. There are hundreds of factories in China producing Lithium cells, but only a handful that produce High grade cells that are suitable for vehicle use and most of them are VERY expensive, some beyond reach of us mere bike riders! There are too many battery packs being sold on Ebay and out of China with claims of using the best LifePO4 cells etc, but the price says otherwise. Be wary of bargains as there are none in China! J
BATTERY BASICS 101
LiMn2O4 Cells have similar safety features to LifePO4, low risk of rupturing or catching fire, but also a lower energy density of only 110-120WH/KG, and a much lower cycle life. They do maintain their voltage and internal resistance better but lose capacity over time/use just like all Lithium cells. They are cheap but not really a good choice for long term use or for bikes more than 200w so we donít import them.
LiNiCoMn Cells are rated medium on the safety chart, they can be damaged by overcharging and it is possible to rupture the cell with the result a battery that burns itself out and smokes the area out, (this is of course possible with any Lithium battery which is why we have a set of instructions on safe handling and storage of Battery packs, and recommend only hi quality computerised chargers). LiNiCoMn battery packs have an energy density of 180-200WH/KG and a higher cell voltage of 3.7v, this means 6 cells has the equivalent voltage of a 7 cell LifePO4 battery, but at a lighter weight, higher energy density and lower cost. The issue with these cells is if overdischarged they die instantly, they have a lower power output ability and must be run with a PCM protection board which limits the current output making them a poor choice for bikes over 250w.
LifePO4 batteries have been used with E-Vehicles for a while now, they are very safe, low risk of rupturing or catching fire, but they are a lower power cell with an energy density of 140-150 Watt-hours/KG and cell voltage of 3.2v so you need more cells to make up the same voltage as a LiPO pack. Their cycle life is very dependant on cell quality, there are a lot of LifePO4 batteries being sold on Ebay and out of China that are low grade 2 cells and many only survive a few hundred charges if you are lucky.
We have run cycle life tests on our Grade 1 LifePO4 cells and after 1000 cycles their internal resistance rises which reduces their capacity and retained voltage under load around 20%. LifePO4 chemistry is also expensive to produce in high quality, we only import the premium grade1 lithium cells which is why the cost can be high.
Lithium Ion 18650 cells are a well known cylindrical cell with 3.7v nominal and 4.2v fully charged. Found in laptop batteries they are usually a low output cell and not really suitable to hi power Ebikes, good for 200-250w bikes if the pack capacity is high enough.
There are some new cells coming out though with hi discharge ratings, Samsungs 25R cells are 2.5Ah capacity and rated at 20A discharge which means 6 of them in parallel will give you 15Ah capacity and 120A discharge rating. These are perfect for building battery packs that are safer than LiPO and have up to 3 times the cycle life. They are not cheap though, but you get what you pay for and the Samsung cells are one of the best on the market, we are looking into building packs with these cells.
LiPO batteries (Lithium Polymer) are extremely high power cells, they feature the highest power density (210WH/KG) and highest output ability, but are also the most dangerous of all lithium cells, overcharging can cause them to rupture and burn, as can physical damage, if the cell is shorted internally it will overheat and rupture within minutes producing a lot of smoke and in severe cases some flame from the end of the pack. Of course this is a worst case scenario and it is very difficult to damage Lipo cells, in 9 years I have not damaged one on a bike or when charging.† It could happen in a severe accident. We currently import only LiPO battery packs for our bikes, the quality and power of the cell is unbeatable for the price and I believe all customers can be educated in safe handling and use of LiPO batteries, why compromise on your bikes performance when all you need to do is educate yourself on good battery handling practices!
NOTE: Using a quality charger and storing the batteries safely in a steel tool box are necessary habits to get in to with Lithium batteries and something we EXPECT our customers to do, itís not a suggestion, and we do not warranty overcharged batteries that are not charged with our chargers.
All our cells are high quality products and the cells are matched for internal resistance and capacity in the factory before being built into battery packs. We are not using the top shelf cells in our current range of batteries because cost factor is huge with hi output lithium cells, for example our 12c battery packs would never be used in Radio Control applications as the discharge rating is too low, but in an electric bike its almost 4 times what is required, so by using lower C rated packs we can keep the cost down around 50% over using a 20-30C cell.
Our Lithium Polymer battery packs typically get 150-200 cycles (sometimes more, sometimes less, depends very much on the user) if correctly maintained and not over discharged or overcharged. Following strict guidelines will get the most life from your batteries, being careless with how you use and store them will result in short lifespans, its possible to kill a Lithium Polymer battery in one go by over-discharging it or leaving it connected to your bike for a long period of time. Whether you have a switch or not makes no difference, if you leave a battery plugged in it will discharge, leave it long enough it will discharge to zero, the cells will drop below 2.9v and the battery will die. They cannot be recovered like this. All our packs have warning labels on them and you MUST get into the habit of double checking everything you do with them.
EXTREME POWER LITHIUM POLYMER BATTERIES
Our Lithium Polymer battery packs have recently been updated and as of November 2014 we have a new range of compact ECO battery packs in 12Ah, 16Ah and 20Ah capacity, all 25v fully charged. The cells are graded and matched together into battery packs then assembled. Our packs are built as 6s1p (6 cells in series) or 6s2p (12 cells in series parallel) with a dedicated balance lead fitted which connects to the balance board of our charger range. Lithium Polymer packs are excellent choice for E-bikes as they have no power limitations from built in PCM or BMS boards, sustain a high output under heavy discharge loads, and can be charged at up to 10Ah if you have a charger capable of enough output.
The EXTREME POWER Lipo packs run in all our kits and are ideal for 500w and 1800W conversion kits. I use these packs in my own 1800W bike and the power is incredible, with the 16Ah packs I am seeing voltage held at 45-46v under full load of 2000+ watts.
You must get into the habit of correctly storing and charging your batteries, there is little risk of failure or damage if you take time to learn and respect these powerful but dangerous devices. I have LiPO batteries in use that are over 5 years old and still able to provide around 70-80% of their original capacity and power rating. All our packs have a plastic wrap around the cell sides before being shrink wrapped. Try not to drop your batteries! They are easily dented and in severe cases you could short out a cell causing it to burn itself out. (hasnít happened but always best to be careful with any battery type).
EXTREME POWER BATTERIES CURRENTLY AVAILABLE:
Size: 55mmx70mmx180mm Weight: 1550 grams
12Ah 22.2v BATTERY PACK:††††† AUD$220.00 inc GST
1 LEFT IN STOCK
Size: 70mmx75mmx180mm Weight: 1950 grams
16Ah 22.2v BATTERY PACK:††††† AUD$275.00 inc GST
EXTREME POWER LIPO BATTERY SAFE BAG
LiPO safe bags are a double wall fiberglass bag designed to hold lithium Polymer batteries and provide a measure of safety against accidental overcharging etc which can lead to the battery burning out. You can store batteries in these bags and charge in them, one battery per bag for our large battery packs, do not try to jam 2 into one bag as you mitigate the performance of the bag. They are cheap enough that you can buy two if you have a pair of our battery packs! J
LIPO SAFE BAG: AUD$13.20 inc GST
TERMS & CONDITIONS:
Riding an Electric bicycle can be a dangerous activity, OZ-eBikes cannot be held responsible for accidents or injury caused by your use of these products. Our warranty responsibility is limited to the products supplied only, and warranty is provided for the supplied products only if they are used as intended. Any modifications to the equipment, use of incorrect batteries or chargers etc will void the warranty.
Lithium batteries are dangerous and must be handled with care; if they are dropped and there is visible damage or deformation of the case you should seek expert advice before continuing to use the battery. Lithium batteries are treated as experimental power supplies, the technology is new and requires education and care in handling, if unsure you need to ask advice and learn correct procedures on handling and storing of Lithium batteries.
We highly recommend purchasing a small $10.00 steel toolbox from Bunnings to store your batteries in when not in use. Batteries MUST be stored and charged outside the house. By purchasing from us you agree to accept full responsibility for the safe handling and usage of our Lithium Batteries. You agree OzEbikes and its partners cannot be held liable for any accident, fire, loss of property or possessions resulting from a lithium battery or charger failure, our instructions on handling and storing are very clear and are the ultimate responsibility of the purchaser.
Batteries must be charged with a specified LiPo charger, we are not responsible for any issues that arise if you use a charger other than the ones we recommend. Our chargers are computer controlled and have advanced settings to ensure the battery cannot be left charging continuously, our chargers automatically shut off when the battery is fully charged.
OZ-EBIKES checks and records the battery pack voltage for every
Lithium battery pack before we send them out. OZ-EBIKES then warrantees all
packs to have proper assembly and cell voltage at time of purchase. In the
event that a customer finds defects in materials or assembly workmanship when
the goods are received but unused, OZ-EBIKES will replace such packs within
OZ-EBIKES does not offer a general warranty for battery packs which have already been charged and discharged, or for which claims are made more than one week after receipt of said battery packs by the customer. Because the majority of Lithium Battery problems occur after initial use and are due to over charge/discharge of the packs or shorted/damaged wiring, it is in most cases difficult to determine the cause of failure, and requires inspection by the manufacturer.
For packs that have been used and which the customer believes are defective, OZ-EBIKES & their manufacturer have agreed to have these inspected at the factory, and replaced if defects are found. In the event that the pack is found not defective or has been damaged by misuse, the pack may be returned to the customer if desired, at the customer's expense.
There is no warranty, expressed or implied, by the manufacturer, distributors or retailers with respect to capacity, life in cycles, storage or discharge characteristics available.
By purchasing any complete kit, battery pack or individual parts from us you agree to our terms and conditions.