lithium & solar power LiFePO4

GWL Power is the largest European micro-inverter support center

We are the larger support, testing and service center for solar micro-inverters by Involar company.

Learn about the micro-inverter technology at EV-POWER.EU.

FAQ: The solar panels and the snow – how to install properly?

The solar panels are designed to resist the heavy winds and the pressure from the loads by thick layers of snow.  What requirements are defining the module load resistance? 

The solar panel load resistance depends on the selection of frame and glass, also is affected by the way a solar panel is installed. Solar panel should have the ability to resist strong winds and heavy snow (for example snow thickness in some areas of northern Europe, or in the mountains may reach up to 2 m). The poor load resistance can lead to solar cell occur micro-cracks.  Unfortunately some producers lower the costs through reducing the thickness of aluminum alloy frame and solar panel glass, in fact weaken load resistance ability of solar panel. In addition, installers could further improve module stability and load resistance by adding multiple module supports (see pictures).

Freewheels for EVBike - available from specialized companies

FAQ: I just bought 36v500w 26“ rear EVBike set. I tried to install Shimano freewheel on it, but it has a lock. In my bike repair shop, they told me that I need spacer for the freewheel. What dimension should be for 7 speed Shimano freewheel?

Answer: There are different combinations of the free-wheels,  we suggest to consult the professional bike components companies who have a wide range of accessories including the spacers.  Some companies offer freewheels designed for E-Bikes (EVBike) directly. See example of such promotion leaflet from a supplier called Sunrace.

FAQ: Is CE Mark needed for lithium cells and batteries?

No. It is not needed.  If you examine cells, battery packs and batteries from renowned producers your will not find any CE Mark. 

The CE mark in Europe is needed only for following groups of complete products:

  • Toys
  • Machinery
  • Electrical equipment
  • Electronic equipment
  • Personal protective equipment
  • Pressure equipment
  • Medical devices
  • Active implantable medical devices
  • In vitro diagnostic
  • Radio and Telecommunications terminal equipment
  • Simple pressure vessels
  • Gas appliances
  • Lifts
  • Recreational craft
  • Equipment and protective systems for use in explosive atmospheres
  • Non-automatic weighing instruments
  • Cableways
  • Construction products
  • Explosives for civil use
  • New hot water boilers
  • Measuring Equipment

Products that are not covered by the European CE marking directives may fall within the scope of other European or national legislation (for example special standards for mining industry, for automotive industry [E-Mark] and for air-craft related parts and products). If there is no specific legislation, the General Product Safety Directive (2001/95/EC) may apply. This European Directives requires that products are safe, but is does not require any marking.

Lithium cells, batteries and packs do not need any CE marking. Complete products or systems with electronics - for example a battery solution consisting of lithium cells and battery management electronics may need to obtain CE tests, if marketed as „Electrical equipment“ or as a part of „Measuring Equipment“. 

The person or company, who is assembling such complete products from individual parts, is the subject responsible to make sure of CE Mark needs to be applied. It is not possible to ask the supplier of just one part (e.g. the supplier of the cells) to give the CE mark documents for a complete product. Those, who are putting components together and sell the product under their (brand) name, need to bear the responsibility for the CE compliance by themselves.

Concerning the CE certification of electrical/electronic devices related to electromagnetic compatibility (EMC): These certifications and tests related to EMC are designed to ensure that electromagnetic radiation (physical radio waves) from components of the complete products do not interfere with other devices such as TV, radios, computers, medical equipment and mobile phones.

However passive components and products (like cells, batteries or battery packs) do not radiate any electromagnetic radiation, and that is why they are not required to undergo the tests.

Some Asian battery manufacturers have been persuaded by various testing organizations that they should be tested and this is why you will see the CE mark on many Chinese batteries.  Or such produces will provide the CE conformity document to you. However such CE marks are false in their placing and are misleading. It is like putting a CE Mark on a piece stone or a tree or onto your house-hold animal. 

If somebody is requesting the CE mark for the cells, batteries or battery packs, it shows his limited knowledge of the conformity procedures.

The Fold-able EVBike - Yes it is possible! 

Converting the fold-able bike into an electric EVBike is possible! The bike keeps to be fully fold-able. Check this smart solution.

New product - Socket for Electric Vehicles according to SAE J1772-2009 including the cable with protection tube (1m, 16A).

The J1772-2009 socket is designed for single phase electrical systems with 120 V or 240 V such as those used in North America, Japan and is still supported by some European car manufacturers. (Renault, Peugeot, Citroen etc.) The connector is needed to use for system with 1 kHz square wave at +/- 12 volts generated by the Electric Vehicle Supply Equipment (EVSE), i.e. the charging station, on the pilot pin to detect the presence of the vehicle, communicate the maximum allowable charging current and control charging.

For technical specification please see: GWL-J1772-Socket-Spec.pdf

Please see actual offer of the J1772-SOCKET.

Customer reference: Revision the batteries after 6 years of operation.

The Customer reference showing the long life-span for the operation of the LiFePO4 block batteries, 12V Winston / Thunder-Sky, used without cell management.

After 6 years of operation in the electric car VW Golf Citystromer, the cells are still in good condition. The revision was carried out to allow the detailed control of the individual cells by newly installed BMS and to change the configuration of the pack to the proper parallel-serial connection. Additionally more new cells were added to increase the total capacity of the pack. The original block 12V batteries were opened and individual cells removed. Now the cells are controlled separately using external BMS.

For information on how to open the actual new models of 12V batteries please see: There are single cells in the 12V LP battery too!

Please see actual offer of the block batteries LP12V 40/60/90Ah.

FAQ: Getting the “EU” socket for EU standard products for 220V/230V

Most products sold in EU have the EU type socket: either the French style with the central ground pin, or the German type - Schuco.

It is quite easy to get the EU type sockets to be able to plug the EU standard products. Simply buy the EU type extension power-strip, and change the “plug-in” head to fit your local socket system. 

The top photo shows the EU extension power-strip with the plug-in head exchanged for the UK style socket. 

The bottom photo shows the same power strip with “traveler sockets” that allow to get universal type of socket (US, UK, China, etc.)

If you need to get the EU type power strips, be sure to contact GWL for help. We are able to purchase locally and resell to you.

Mr. Winston Chung visited UC Riverside in March 2014

Learn about the details for the visit of Mr. Winston Chung, the CTO and the founder of the Winston Battery, to the the Bourns College of Engineering, UC Riverside, USA. See the photo-shoot from the visit. Learn about the progress of the reseach of the LiFePO4 basic element structure.

GWL is the European distributor of the Winston Battery products.

The news for EVBike

We keep improving the EVBike products. Stayed tuned for more news coming. 

New models from Sinopoly 66AH and 100AH
The Sinopoly has introduced the new small size factor model 66AH. This model will be followed by the new 100AH model later in 2014. The photo shows the engineering sample of the new 100AH model. We will keep you updated for more news on these new products.
You can order the 66AH model from our stock on-line.

New models from Sinopoly 66AH and 100AH

The Sinopoly has introduced the new small size factor model 66AH. This model will be followed by the new 100AH model later in 2014. The photo shows the engineering sample of the new 100AH model. We will keep you updated for more news on these new products.

You can order the 66AH model from our stock on-line.

FAQ: How does the EMF-1 wattmeter show power supply to the grid?

The usage of EMF-1 is very simple. The wattmeter will show the power supplied to the grid the same way, as it shows the consumption from the grid. There is no “plus” or “minus” sign. The wattmeter shows only the actual value, no matter in which direction the energy is flowing.   Measuring values in Watts or Amperes are supported. 

Check our animation for the use of the micro-inverters in the Grid-Free installation. This will give you the idea how the current is flowing. You can make also some tests to connect the meter to various places to see the results. 

As seen in the animation, if there is another appliance consuming power connected to EMF-1 together with microinverter, EMF-1 will show the difference between the power supplied to grid and power taken from the grid!   (300W consumption, 230W from the solar panel, 70 W is the difference taken from the grid).

Note: please see the EFM-1 manual to understand how the power factor influences to the power reading on the meter: even though the inverter may give the full power of 230W, the reading value on the EFM-1 may be lower because of the power factor difference. 

Logging the EVBike performance with the Speedict 
The simple solution to monitor your EVBike electrical parameters: the analyst cyclecomputer - Speedict MARS.  The analyst software allows uploading the data to the web server so that see and share your driving performance results with others. 
Be sure to check with us for more EVBike products coming!

Logging the EVBike performance with the Speedict 

The simple solution to monitor your EVBike electrical parameters: the analyst cyclecomputer - Speedict MARS.  The analyst software allows uploading the data to the web server so that see and share your driving performance results with others. 

Be sure to check with us for more EVBike products coming!

Question: Can the micro-inverter (in the GridFree installation) work in an island mode against some sine wave DC/AC generator? (e.g. in parallel with my own  independent 230V island system)?
Answer:  No, the microinverter in most cases will not work with in such mode. There are several reasons:
1) For legal and safety reasons the microinverter works only when connected to a real 230V AC grid. The inverter will start working only after detecting the presence of the real 230V AC grid power line. It will not start working with some simulated 230V AC power system.
2) The inverter must meet the exact requirements for the European 230V AC grid based on the strict settings given by the EN50438. The inverter must stop working if the specifications of the grid do not match the parameters given by this standard. For this reason the invertor will not work with some independent 230V island systems. Additionally the strict requirements of the EN50438 make the inverters non-functional in countries, where the quality of the grid is poor and unstable. 
3) For safety and legal reasons the micro-inverter works only in grid-tied mode. The island mode is not supported and trying to experiment with such operation is against the warranty conditions for this product.
4) Trying to connect to the input of DC/AC off grid inverter will most like result in burning the output of this equipment, since these products are designed to provide energy to the load and they are not designed to handle to receipt of energy from a parallel source. 
5) The impedance, voltage a power ratings of the real grid are far beyond the possibilities to emulate these in some small installations. Each microinverter contains high-tech protection and grid detection components. The inverter will not start when the real grid is not detected. 
Conclusion:
The MicroInverters work only with the 230V AC real grid that meets the limits of the specifications given by the EU standards. For technical, safety and other reasons the inverters cannot work against a simulated (local) power source. Additionally the MicroInverters are not allowed and cannot work in an island mode.

Question: Can the micro-inverter (in the GridFree installation) work in an island mode against some sine wave DC/AC generator? (e.g. in parallel with my own  independent 230V island system)?

Answer:  No, the microinverter in most cases will not work with in such mode. There are several reasons:

1) For legal and safety reasons the microinverter works only when connected to a real 230V AC grid. The inverter will start working only after detecting the presence of the real 230V AC grid power line. It will not start working with some simulated 230V AC power system.

2) The inverter must meet the exact requirements for the European 230V AC grid based on the strict settings given by the EN50438. The inverter must stop working if the specifications of the grid do not match the parameters given by this standard. For this reason the invertor will not work with some independent 230V island systems. Additionally the strict requirements of the EN50438 make the inverters non-functional in countries, where the quality of the grid is poor and unstable. 

3) For safety and legal reasons the micro-inverter works only in grid-tied mode. The island mode is not supported and trying to experiment with such operation is against the warranty conditions for this product.

4) Trying to connect to the input of DC/AC off grid inverter will most like result in burning the output of this equipment, since these products are designed to provide energy to the load and they are not designed to handle to receipt of energy from a parallel source. 

5) The impedance, voltage a power ratings of the real grid are far beyond the possibilities to emulate these in some small installations. Each microinverter contains high-tech protection and grid detection components. The inverter will not start when the real grid is not detected

Conclusion:

The MicroInverters work only with the 230V AC real grid that meets the limits of the specifications given by the EU standards. For technical, safety and other reasons the inverters cannot work against a simulated (local) power source. Additionally the MicroInverters are not allowed and cannot work in an island mode.

The new profesional Battery for EV bikes 36V & 48V

The new series of batteries for electric bikes, contains smart BMS circuit that continuously monitors the quality of internal cells and in case of failure, provides actual information through an LED panel. Please see PDF specification of LED faults. This circuit also protects the battery against deep discharge. 

NOTE:

If the battery is discharged so that it turns off the internal BMS module, next charging turns up in a few hours. Therefore is necessary to keep connected charger on the battery until it does not start charging.