lithium & solar power LiFePO4

Simple solutios to keep your battery warm in winter

DC and AC power based warming pads will provide sufficiant heating power to keep the battery warm during cold winter days and nights.

In order to keep the thermal energy, it is strongly recommended the battery pack is properly insulated from outside cold.

DC Wattmeter using the LAN-Module controller

The LAN module controller can be used to measure the DC power. Check the idea in the application document. 

More details about the LAN controller.

The logging of data from the LAN controller can be made publicly available by means of  https://thingspeak.com web service. 

Warning: Avoid any risks when working with the high-voltage DC ratings! Beware of the dangers of electric shocks or even death!

DC Wattmeter using the LAN-Module controller

The LAN module controller can be used to measure the DC power. Check the idea in the application document.

More details about the LAN controller.

The logging of data from the LAN controller can be made publicly available by means of https://thingspeak.com web service.

Warning: Avoid any risks when working with the high-voltage DC ratings! Beware of the dangers of electric shocks or even death!

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.

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.

EV-BIKE battery connector

All EVBike kits are factory-equipped with 4-pin connectors, which are able to operate with high current from the EVBike lithium batteries. In case your connector is broken or if you are thinking of making your own strong EVbike battery from small LiFePo4 cells, you can buy spare MC12-4P connectors at EV-POWER.EU.

Examples of custom battery packs for hi-power EV-BIKE conversions:

Also do not forget to ckeck the proper polarity of the pins (plus and minus wiring).

The alarm output for CellLog
One of the Cell Logger’s functions is the alarm output. The Alarm output can be triggered according to several settings of the CellLog. It uses the open collector design - this kind of output can be found on many integrated circuits or electronic modules.
How to connect a DC relay to this alarm output: The output forms either an open circuit or a connection to ground. This gives you the advantage of switching loads up to 50V and 500mA. In other words it can be possible to control 12/24V relay easily. In most cases the power to trigger such a relay will be provided from a separate power supply (e.g. isolated DC-DC). In case you connect the relay to the battery directly, please note that ground pin of the ALARM is not isolated! It is connected to the GND of the battery pack.
See an example connection of 24V relay to 8 cell LiFePO4battery pack. This way you can turn off your charger or disconnect the main contactor in case alarm is triggered. Do not forget to connect the protective diode parallel to the relay-coil otherwise you will most probably break the output!

The alarm output for CellLog

One of the Cell Logger’s functions is the alarm output. The Alarm output can be triggered according to several settings of the CellLog. It uses the open collector design - this kind of output can be found on many integrated circuits or electronic modules.

How to connect a DC relay to this alarm output: The output forms either an open circuit or a connection to ground. This gives you the advantage of switching loads up to 50V and 500mA. In other words it can be possible to control 12/24V relay easily. In most cases the power to trigger such a relay will be provided from a separate power supply (e.g. isolated DC-DC). In case you connect the relay to the battery directly, please note that ground pin of the ALARM is not isolated! It is connected to the GND of the battery pack.

See an example connection of 24V relay to 8 cell LiFePO4battery pack. This way you can turn off your charger or disconnect the main contactor in case alarm is triggered. Do not forget to connect the protective diode parallel to the relay-coil otherwise you will most probably break the output!

Dual battery monitoring BMS + CellLog8
An example of a real installation: 24V battery pack consisting of 8 pcs of LFP cells. The monitoring and management is done by the BMS123 system. In order to have a fast overview of the status of the cells, the CellLog8 is added in parallel to the cells.
This allows to have a fast overview of the status of the cells. Also additional alarm can be triggered using the ALARM output of the CellLog8.
Check the CellLog8 and BMS123 at EV-POWER.EU.

Dual battery monitoring BMS + CellLog8

An example of a real installation: 24V battery pack consisting of 8 pcs of LFP cells. The monitoring and management is done by the BMS123 system. In order to have a fast overview of the status of the cells, the CellLog8 is added in parallel to the cells.

This allows to have a fast overview of the status of the cells. Also additional alarm can be triggered using the ALARM output of the CellLog8.

Check the CellLog8 and BMS123 at EV-POWER.EU.

How to increase co-operation with GWL and to promote your own business
We receive many ideas for co-operation from many countries and places. We are happy to support individual people, small companies or businesses to grow and enhance the co-operation with GWL.
Even though we welcome co-operation with everybody, we honestly say that we wish to support only those who make some real action rather than speaking too much.
The basic information about co-operation with GWL is explained at the FAQ section at our EV-POWER.EU shop.  See the answer to the questions:
Can I get a discount from the web shop prices? Can I get “dealer discount”?http://www.ev-power.eu/Frequently-asked-questions/#a09
I need special pricing for a large project. What can you do for me?http://www.ev-power.eu/Frequently-asked-questions/#a10
To demonstrate your real interest about the co-operation, we suggest following ideas:
Translate and promote the web informationStart with translating and promoting the technical information from our web pages and GWL/Blog. We warmly invite you to use the information published at our sites to promote the solutions to your local customers. Make your own web page, create your own blog, and make your own profile. Simply be active!
Publish your own workMake pages with updates about your own work, about your projects and their progress. It is so simple. Take your camera; make few photos, white few words.  This will show you wish to work more than just speak!
Request samples from GWLWe will be happy to offer samples to you to start the co-operation. We are able to provide samples of the products from our offer and to sell these samples to you at a reduced price. However we do not provide free samples.  Also we usually limit the sample order to one per customer. So it is good to make a bigger order requesting more samples to start fast.
Are you ready to start?
PS: See reasons with advantages for you that GWL gives you

How to increase co-operation with GWL and to promote your own business

We receive many ideas for co-operation from many countries and places. We are happy to support individual people, small companies or businesses to grow and enhance the co-operation with GWL.

Even though we welcome co-operation with everybody, we honestly say that we wish to support only those who make some real action rather than speaking too much.

The basic information about co-operation with GWL is explained at the FAQ section at our EV-POWER.EU shop.  See the answer to the questions:

To demonstrate your real interest about the co-operation, we suggest following ideas:

Translate and promote the web information
Start with translating and promoting the technical information from our web pages and GWL/Blog. We warmly invite you to use the information published at our sites to promote the solutions to your local customers. Make your own web page, create your own blog, and make your own profile. Simply be active!

Publish your own work
Make pages with updates about your own work, about your projects and their progress. It is so simple. Take your camera; make few photos, white few words.  This will show you wish to work more than just speak!

Request samples from GWL
We will be happy to offer samples to you to start the co-operation. We are able to provide samples of the products from our offer and to sell these samples to you at a reduced price. However we do not provide free samples.  Also we usually limit the sample order to one per customer. So it is good to make a bigger order requesting more samples to start fast.

Are you ready to start?

PS: See reasons with advantages for you that GWL gives you

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.