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.
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)
Beware of the danger of electric shock, burns and sparks!
The photo shows that even skilled profesionals can make a mistake and burn the battery terminal in a fraction of a second……..
The lesson learned is: Pay more than a usual attention to your work when assembling the battery packs and sets.
Keep in mind that the energy stored in the lithium cells may cause severe burns or fires if discharged improperly. source