lithium & solar power LiFePO4

Improving thermal codition of flexible panels

Placing flexible solar panels on “Makrolon Plaxiglas" type structure will improve the airflow behind the solar panel backsheet. This can help cooling the solar panel down and increase the performance in hot weather periods.

Multiple CellLogs on computer cables

See a hint how to join multiple CellLogs together using the computer dataline cables.

Note: never connect the USB port of multiple CellLogs connected on a the same battery pack. The USB ports have different voltage potentials and the connection will lead to a short-circuit.

Order CellLogs here at EV-POWER.EU

How to improve performance of EVBike battery?
Did you know that both EVBAT36V7A and EVBAT36V10A batteries have integrated balancing circuit? If you keep your standard ev-bike charger connected over night (green LED ON), the charger will balance weaker cells up to the level of the strongest ones in the battery with a low current. If the performance of your battery is not as brand new, it is recommended to proceed balancing once per 10 rides. Balancing is also recommended when the battery was not used for several months, for example after winter. (Balancing of a brand new battery is not necessary and might actually shorten its lifetime.)

How to improve performance of EVBike battery?

Did you know that both EVBAT36V7A and EVBAT36V10A batteries have integrated balancing circuit? If you keep your standard ev-bike charger connected over night (green LED ON), the charger will balance weaker cells up to the level of the strongest ones in the battery with a low current. If the performance of your battery is not as brand new, it is recommended to proceed balancing once per 10 rides. Balancing is also recommended when the battery was not used for several months, for example after winter. (Balancing of a brand new battery is not necessary and might actually shorten its lifetime.)

Improving the EMC and reducing the undesired signal radiations
Most electronic products contain high frequency circuits. These may radiate some electromagnetic waves. When assembling products from individual components it is good to keep in mind that the final product and its installation should be designed in a way to reduce the radiation of electromagnetic fields.  This is called the EMC – electromagnetic compatibility. Some general tips and ideas are listed bellow:
Short cables – try to make all cables as short as possible. Long cables naturally serve as antennas sending out the undesired spurious signals.
Keep cables together or even twist them. This helps to reduce the electromagnetic noise a lot.
Filters and shielding - Use ferrite filter coils and metallic shielding (braiding) on the cables and wires.
Metallic housing and proper grounding - Mount your equipment into a metallic housing with proper grounding of all non conductive metallic parts. Position the equipment to a location far from your radio receivers or other sensitive equipments.
Note: Most products (especially components) that comply with EMC standards by themselves may radiate undesirable signals if installed improperly. The installers must follow the generic and manufacturer’s guidelines to keep EMC standards.

Improving the EMC and reducing the undesired signal radiations

Most electronic products contain high frequency circuits. These may radiate some electromagnetic waves. When assembling products from individual components it is good to keep in mind that the final product and its installation should be designed in a way to reduce the radiation of electromagnetic fields.  This is called the EMC – electromagnetic compatibility. Some general tips and ideas are listed bellow:

  • Short cables – try to make all cables as short as possible. Long cables naturally serve as antennas sending out the undesired spurious signals.
  • Keep cables together or even twist them. This helps to reduce the electromagnetic noise a lot.
  • Filters and shielding - Use ferrite filter coils and metallic shielding (braiding) on the cables and wires.
  • Metallic housing and proper grounding - Mount your equipment into a metallic housing with proper grounding of all non conductive metallic parts.
    Position the equipment to a location far from your radio receivers or other sensitive equipments.

Note: Most products (especially components) that comply with EMC standards by themselves may radiate undesirable signals if installed improperly. The installers must follow the generic and manufacturer’s guidelines to keep EMC standards.

How to connect LP12V90AH+ batteries together to get a 24V pack?

A simple solution to make a 24V 90AH battery pack. When positioned next to each other (as shown at the picture) CALB180 terminal connectors are compatible and make a cheap solution! 

Please note that you need to charge both of the 12V batteries to full foltage to get them balanced before using the two batteries as 24V pack.

Check links:
CALB180 terminal connectors  - http://www.ev-power.eu/_d2796.html
LP12V90AH battery - http://www.ev-power.eu/_d1873.html

FAQ: Charger performance loss due to a poor connection of the clamps
Question: We have a charger with the specification of 20Amp current. However the current of the charger is sometimes lower.  Why is this so?
Answer: For high current charge and discharge, the resistance of the connections is significantly important. If the connection is not good it will cause overheating and the energy loss.  For example, some of the chargers have clamps to connect to the battery. If the clamps on the battery terminals are not positioned properly there maybe a loose connection that will cause energy losses.  As a result, with the increased resistance, the current of the charger may be reduced.
Solution tips: check the cabling of the charger, check the tightness of the clamps, remove any dirt from the terminals, do not connect the clamps to iron screws, connect to copper or aluminum terminals directly. For best performance use properly soldered hooks rather than the clamps.
Check also this article on voltage drop

FAQ: Charger performance loss due to a poor connection of the clamps

Question: We have a charger with the specification of 20Amp current. However the current of the charger is sometimes lower.  Why is this so?

Answer: For high current charge and discharge, the resistance of the connections is significantly important. If the connection is not good it will cause overheating and the energy loss.  For example, some of the chargers have clamps to connect to the battery. If the clamps on the battery terminals are not positioned properly there maybe a loose connection that will cause energy losses.  As a result, with the increased resistance, the current of the charger may be reduced.

Solution tips: check the cabling of the charger, check the tightness of the clamps, remove any dirt from the terminals, do not connect the clamps to iron screws, connect to copper or aluminum terminals directly. For best performance use properly soldered hooks rather than the clamps.

Check also this article on voltage drop

FAQ: I have 144 volts LiFePO4 cells in my own car, when I used it at full throttle for 2 or 3 seconds, it went from the nominal voltage to below 120 volts until the electronics shutdown the car. Why is this so?
Answer: We have many experiences showing that proper cabling and proper cell terminals (between each cell) are very important to prevent the voltage drop (also called voltage sag) at high current flows.
We suggest following:
1) Clean once more the terminals of the cell properly again2) Use double or triple copper cell terminal connectors3) Increase the size (the diameter) of the cables to the engine
These simple steps can make very significant improvements!
(Image from Wikipedia)

FAQ: I have 144 volts LiFePO4 cells in my own car, when I used it at full throttle for 2 or 3 seconds, it went from the nominal voltage to below 120 volts until the electronics shutdown the car. Why is this so?

Answer: We have many experiences showing that proper cabling and proper cell terminals (between each cell) are very important to prevent the voltage drop (also called voltage sag) at high current flows.

We suggest following:

1) Clean once more the terminals of the cell properly again
2) Use double or triple copper cell terminal connectors
3) Increase the size (the diameter) of the cables to the engine

These simple steps can make very significant improvements!

(Image from Wikipedia)

RC model Li-Poly battery pack for EVBIKE

Some experienced users may wish to use the Li-poly battery packs to make small size battery for their EVBike. This is a possible solution - getting full power while saving space and weight.

However, please remember that the Li-poly battery is very sensitive to over-charging, deep discarge and brings some additional risks. It is recommended only for experienced users, not for general public.  Also the R/C model battery packs usually do not have any protection, so an additional cell and battery protection is needed.  You may also need to get a special cell balancing charger to re-charge these packs properly.

GWL does not offer Li-Poly R/C model cells. We specialize in the safe LiFePO4 technology. The Li-Poly R/C cells and packs are available from many Hobby-shops.

Simple hint for the installation of the Micro-Inverter
You can mount the solar panel right on the outside of your window. This will firstly protect from the direct sunshine in hot summer days (thus reducing the heat coming into your room). The solar panel and the Grid-free micro-inverter will generate up to 230 Watts of free energy that you can use in your house.
For example the self-generated enegry can be used to reduce your consumption from the grid and thus saving on payments for the energy needed to run the air-conditioning in summer.
Start using GridFree!  http://www.ev-power.eu/GridFree-Inverters/

Simple hint for the installation of the Micro-Inverter

You can mount the solar panel right on the outside of your window. This will firstly protect from the direct sunshine in hot summer days (thus reducing the heat coming into your room). The solar panel and the Grid-free micro-inverter will generate up to 230 Watts of free energy that you can use in your house.

For example the self-generated enegry can be used to reduce your consumption from the grid and thus saving on payments for the energy needed to run the air-conditioning in summer.

Start using GridFree!  http://www.ev-power.eu/GridFree-Inverters/

Terminal protectors for LiFePO4 cells

The terminal protectors cover the cells terminals (plus and minus) to prevent from accidental short circuit during manipulation with the LFP cells.

There are single cells in the 12V LP battery too!

Check this tip:  sometimes it may be smarter to choose the 12V LP monolithic LiFePO4 batteries instead of individual 3.2V rated cells. The reason is simple – the 12V LP batteries contain a pack of four completely identical 3.2V cells integrated inside of the plastic case.

If individual cells are not on stock, purchasing the 12V LP batteries instead of separate cells is quite advantageous.  When buying the 12V batteries your will not only get the finely balanced 4 cells, but there are stainless steel bolts and copper terminal connectors included with the battery as well.  With the 12V LP batteries you get these for free!

As the photos show, it is quite easy and simple to open the 12V battery to get access to the individual cells.

Check our offer for Winston 12V 90Ah (http://www.ev-power.eu/_d1873.html), Winston 12V  60Ah (http://www.ev-power.eu/_d1872.html) and Winston 12V  40Ah (http://www.ev-power.eu/_d1871.html) models, that can be modified to access the single cells. 

Home Solar Solutions
The photo shows the example of installing the household solar solution even at the blocks of apartment buildings.  Here the solar collectors are combined with thermal solar installation.
The GridFree solution can be also installed in the same way to allow microgeneration of energy to reduce the consumption of the energy from the grid.

Home Solar Solutions

The photo shows the example of installing the household solar solution even at the blocks of apartment buildings.  Here the solar collectors are combined with thermal solar installation.

The GridFree solution can be also installed in the same way to allow microgeneration of energy to reduce the consumption of the energy from the grid.

Safe Disposal of Damaged Batteries
Some times it happens that the LiFePO4 cells or batteries get damaged due to an improper use such as deep discharge or over charge.  Such cells or batteries cannot be repaired and must be disposed of properly.If necessary, to dispose of damaged batteries with LiFePO4 technology, we strongly recommend that you first discharge down to 0V [zero] and then link the terminals of the cell or battery with a simple wire jumper. This way you will prevent from the battery to regain some energy from the continuation of the chemical processes.

Safe Disposal of Damaged Batteries

Some times it happens that the LiFePO4 cells or batteries get damaged due to an improper use such as deep discharge or over charge.  Such cells or batteries cannot be repaired and must be disposed of properly.

If necessary, to dispose of damaged batteries with LiFePO4 technology, we strongly recommend that you first discharge down to 0V [zero] and then link the terminals of the cell or battery with a simple wire jumper. This way you will prevent from the battery to regain some energy from the continuation of the chemical processes.

A Battery Care Function - Charging Level
Some notebooks have now the battery care function. This function saves the battery life and increases the life-span by not charging the battery to the full.
In a normal notebook use, if you stay on AC-power for long time, you may save the battery by low level charging. If you stay outside a lot, you may decide to change the charge to full 100% again.
The same idea may be used for the lithium battery applications as well. The same logic is applied for LiFePO4: the lower the charge/discharge cycle, the longer the life-span.

A Battery Care Function - Charging Level

Some notebooks have now the battery care function. This function saves the battery life and increases the life-span by not charging the battery to the full.

In a normal notebook use, if you stay on AC-power for long time, you may save the battery by low level charging. If you stay outside a lot, you may decide to change the charge to full 100% again.

The same idea may be used for the lithium battery applications as well. The same logic is applied for LiFePO4: the lower the charge/discharge cycle, the longer the life-span.

A simple solution to protect against short-circuit
We strongly recommend to have all instruments and tools fully insulated against accidental short-circuit.

A simple solution to protect against short-circuit

We strongly recommend to have all instruments and tools fully insulated against accidental short-circuit.