Observe the polarity! Use the proper fuses!
The photo shows the EVBike Central controller after the customer installed the battery with opposite polarity without fusing. Most DC powered products are very sensitive to the wrong polarity of the battery. Always check the proper polarity before installing the battery or turning on the main switch.
Also always make sure there is a proper DC fuse between the battery and the controller. This will protect the controller or the battery against a sudden discharge in case of short circuit.
In the case of EVBike the controllers for the motors are tested in the factory before the assembly. Also after the assembly the whole kit is tested again to see the performance of the motor. In case of some internal problem on the controller board or the electronics this problem will be detected during the tests. The significant burns of the controller board are cause by wrong polarity and using a battery with no fuse.
This damage of the controller is not a warranty case to be covered by the manufacturer.
Charging with up to 16 Amp – check your AC socket quality first!
For 16 Amp charging currents we recommend to connect the open end of the charging cable directly to an electrical distribution board. It is also recommended to use CEE Caravan plug or the 3-phase 16/32A 400V 5pin plug.
In case of using common Schuko 16A home plug there is higher risk of melting the connector while operating with more than 10A continuously. Only high quality rubber connectors should be used! Check the socket quality - especially the springs (which hold the contact) for aging!
Can a LiFePO4 battery set itself on fire?
In some very rare cases any battery can set itself on fire. There are examples of situations when a battery (in a mobile phone) set itself on fire. This may happen perhaps once in 10 000 units, once in a period of 5 years. Will you stop using mobile phones because of this danger?
In fact: the LiFePO4 technology is much more stable and much safer than the Li-poly cells used in mobile phones, tablets and notebooks. While the Li-poly cells may actually explode and burn completely very fast (nearly instantly), the LiFePO4 cells usually remain complete and only the plastic case or internal material may burn slowly (for many minutes).
During the last 6 years of our battery business at GWL, we have sold over 15 000 000 Ah of cell capacity: this corresponds to some 300 000 pieces of individual cells. From this quanity we have recored only less than 10 cases of battery related fire. In fact from these less than 10 cases, most were related to electric short curcuit (user failure), not to a battery (cell) failure. Others were caused by over charging. This proves the LiFePO4 technology is extremely safe and reliable.
Will you stop using mobile phones because of lithium cells? Will you stop using LiFePO4?
Proper connectors - the must to avoid problems in the future
The photo shows the EVBike connectors (at the motor side) that were burnt during a period of use. The reason of such a situation is the dirt on the terminals and the improper connection. During high current peaks, the connectors overheat and the resistance of such connectors is increasing. The more the resistance is increasing, the more heat is emitted. As a result the connector may become burnt completely.
Make your connections proper. Keep your connectors clean.
LFP cells will bloat if overcharged
The photo shows the results of an unattended charging from a regulated charger that had a failure. The cells were kept charging up to 4.8V per cell.
The result is obvious: due to the overcharge the cells start swelling and the housing expands.
On the other hand, this accident proved that LiFePO4 cells are a quite safe battery technology. In this hazardous situation, there was no significant temperature increase, no gas leak, no explosion, no fire. (With lithium polymer cells - so called „lipoly“ cells - such kind of over charge would result in an uncontrolled fire.)
The lesson taken from this accident:
- Never left batteries charged unattended.
- Always install multiple protections to have a backup protection in case of failure of the primary device.
- Operate batteries in places where there is a proper fire safety (not on a wooden table in a closed room).
- Even professionals can make a mistake or meet with a failure that can lead to an accident.
Be careful about the DC voltage accidents!
Micro-Inverter – No Fear of Death
Standard PV installations with work with DC 400V to DC 800V. Total risk of electric shock and death ! ! !
With Micro-Inverter working with DC 50V – 100% SAFETY - no risks of burns, shocks or deaths because of high DCa voltages.
Make your own solar instalation as safe as possible. Use only low voltage DC micro-inverters.
A simple solution to protect against short-circuit
We strongly recommend to have all instruments and tools fully insulated against accidental short-circuit.
Improper installation causing terminal overheating and cell damage
The photo shows a cell with a damaged terminal. The improper installation left some dirt and high resistance on the terminal connector flat area. The high currents cause over-warming and further increase of the resistance. The result is complete damage of the cell by terminal overheating.
The power of electric induction
A simple mistake: the cable rolled up on a wheel-cable extension cord used to charge an EV. Never forget that even few loops on a cable can cause severe heating by electric induction.
Warning: Cell Terminal Corossion
Improper installation, dirt on the terminals, air humidity, salty air, influence of acids, oxidizing, high currents, insufficiant maintenance, complete ignorance….. all these factors increase the risk of terminal corossion.
This photo shows a completely damaged terminal that may cause over heating or even fire under high currents.
FAQ: Replacing a defective cell with a new cell
Question: I have bought 50 lithium cells. After 3 years, I have found out that one or two cells are defective. How can I replace the defective cell?
Answer: Generally said you can replace a defective cell in a string of LFP cells with a new cell of the same capacity (or higher capacity). As the new call has full capacity performance, the new cell will not influence the performance of the whole pack. Some customers decide to buy some extra cells to have them on hand in case of a cell failure. However in order to keep these extra cells fresh over a period of many years, it is necessary to charge and discharge the extra cells from time to time.
Note: most cell failures are direct results of deep discharge, over charge or improper balancing. We strictly recommend avoiding such situations to keep the long lifetime of the cells.
The PCM circuit of the LFP batteries cannot replace proper fusing
Recently there were several cases of customers who damaged the LFP batteries with the PCM by over current or short-circuit. As any batteries, the batteries with the PCM protective board need to be fused by a proper size fuse. In case of an accidental short-circuit connection, the fuse will protect the battery against high current that can cause the damage the PCM board and the whole battery.
The photo shows one instance of improper use of the LFP battery with the PCM. The two places on the battery connector plus pole prove the repeated over-current that even melted the connector.
The damage by over-current is not covered by manufacture warranty and there is no way to repair a battery that was damaged this way.
Improper packing of additional mounting hardware can cause a severe energy/heat discharge. The metalic parts can make the short-circuit of the cell terminals. Never allow the terminals to be in short-circuit.
The photo of a damaged 12V battery
This photo shows the results of a severe battery abuse and following dissambly. You can see that the LiFePO4 is a 100% safe batery technology: no fire, no explosion, no dangerous acids, gases and chemicals. (source)