Showing posts with label battery charger. Show all posts
Showing posts with label battery charger. Show all posts

Thursday, January 14, 2010

Super Power -- AXI Gold Line Double 5330/20 Outrunner


Special power unit based on two AXI 5330 motors was custom designed for aerobatic models of planes up to 16000g. Maximum burst power of this unit reach 6000Watts. DOUBLE AXI 5330/20 GOLD LINE is suitable for use with single propeller but is also ready for two contra rotating props.



Electric motors manufactured by Modelmotors are marked with name and numbers with slash. Name means type of motor (eg.: AXI - brushless 14-pole outrunner, MiniAC - brushless two-pole inrunner). First two numbers mean diameter of stator and next two numbers lenght of stator in mm. Simplified the bigger diameter and lenght the bigger power of motor. The number behind the slash is winding number. The lower winding number the higher RPM and current capacity.

•No. of cells: 10s Li-Poly
•RPM/V: 235 •Max. efficiency: 91%
•Max. efficiency current: 23 - 57A (>85%)
•Current capacity: 75A / 20s
•No load current: 1.8A - 3A
•Internal Resistance: 2 x 45m ohm
•Dimensions (Diameter x Length): 63 x 159mm
•Shaft diameter: 8mm / 32mm
•Weight with cables: 1150g

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Thursday, September 3, 2009

How To Safely Use, Charge, and Discharge Lithium Polymer (Lipo) Batteries

Lithium polymer batteries are great for RC aircraft, but they have an explosive chemistry that must be treated with caution.

Prevent this from happening to your batteries by following these tips:

  1. Store lithium polymer batteries in a flame proof LipoSack while charging. - Charging your lithium polymer batteries in a flame proof LipoSack can contain a fire should it occur. It could mean the difference between a minor clean up and the loss of your house or car. Also make sure that the storage area is well ventilated.
  2. Read the manual – The importance of reading your battery and chargers manual cannot be emphasized enough. The battery manual will state the proper charging rates and times.
  3. Use common sense – Don’t charge batteries unsupervised. Even when you do everything right, incidents can occur. Also, do not charge lithium polymer batteries in your car. A flame out can be disasterous if it occurs inside a vehicle.
  4. Use the right battery charger – Charging a lipo battery with a charger designed for other batteries will cause problems, and will probably result in a fire.
  5. Charge lithium polymer batteries on a fire proof surface – It’s really important to charge lithium polymer batteries on a flame proof surface such as concrete. In the event of a fire, a fire proof charging surface will stop it from spreading, or at least slow it down significantly.
  6. Keep a fire extinguisher, or bucket of sand near the charging area – If a fire does occur, you don’t want to be running around looking for something to put it out with. Water will not help put out a lipo fire. Being a conductor, it will cause a short circuit and could even make the fire worse.
  7. Don’t charge lithium polymer batteries near flammable substances – lithium polymer batteries are flammable enough as it is. Don’t make the problem worse by storing flammable substances near charging batteries.
  8. Check lithium polymer batteries for swelling prior to charging and each use – A puffed battery is unstable, and can be in danger of exploding. If you see a puffed battery, immediately disconnect it from the charger or aircraft and put it in a bucket of water. Dissolve a few tablespoons of salt in the water to aid conductivity, and leave the battery in the bucked for about 4 days. The salt water depletes any power remaining in the battery by creating a short, and it can’t catch fire while underwater. After the four days are up, take the battery out and cut off the connectors (which may come in handy for other projects). You can then dispose of the battery in the trash. The battery no longer contains toxic metals, won’t harm the environment, and by using the salt water you’ve guaranteed that it won’t catch fire. This should be done as soon as you see a puffed battery. You can’t salvage a puffed battery, the best you can do is to dispose of it safely.
  9. Never charge a lithium polymer battery in a model – If you charge a lipo battery in your RC airplane or helicopter, you are risking the total loss of your model. Only charge lithium polymer batteries on a flame proof surface, in a LipoSack.
  10. Make sure the charging leads are connected properly – Connecting positive to negative and negative to positive can cause a major fire.
  11. Don’t overcharge batteries – By their very chemistry, lithium polymer batteries cannot be discharged to a potential of less than 3 volts without damage. For the same reason, don’t charge them to over 4.2 volts. This means that you have to land your rc aircraft before the motors stop turning. Some aircraft come equipped with a voltage cut-off, others do not. If you don’t have a voltage cut-off, then land as soon as you sense the propeller or rotors slowing down.
  12. Double check that the charger settings are correct – Lithium polymer battery chargers require you to set the battery configuration. Ensure that this configuration matches the battery you’re charging, or else your lipo could get overcharged and explode. Some chargers automatically sense the battery configuration, but make sure that the setting is correct regardless. They have been known to be wrong on occasion.
  13. Balance lipo batteries – Lithium polymer batteries have balance connectors, designed to make sure that each cell in the pack has the same charge. If this isn’t the case, some cells can become overcharged and explode.
  14. Never let the battery leads touch – If the battery terminals touch each other, the battery will short circuit and, in most cases, be destroyed. If this happens and you get a puffed battery, dispose of it by following tip 9 above.
  15. Don’t ever store / charge lithium polymer batteries in your car – Unless you hate your car. Batteries can and do explode, and if this happens inside a vehicle the result is usually catastrophic. On a hot day, temperatures can rise inside the car and cause stored packs to rupture.
  16. In the event of a crash, remove the battery and supervise it for at least 4 hours – A crashed plane’s battery can appear fine, but can have an internal short circuit. This short circuit can cause an explosion, even hours after the crash occurred. A LipoSack is a great place to keep a battery that’s been in a crash. If enough time elapses and nothing happens, then your battery is probably fine. If you see puffing, dispose of it immediately following the instructions in tip 9 above.

Always use common sense, read the manual, and know the risks associated with lithium polymer batteries. Handled properly, the risk of a fire is relatively small. Store lithium polymer batteries in a LipoSack for additional saftey.



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Saturday, August 29, 2009

My recommend Battery Charger (2)

In last few day, I recommend two battery chargers to my friend. Today, I will introduce the last one battery charger to you~



G.T.POWER A6 Digital LiPo Li-polymer Balance Charger

The A6 balance charger is a rapid charge / discharger with built in balancer, computerised with micro-oprocessor and specialised operating software.

Specifications

Features
Optimized operating software
When charging or discharging, It has an 'AUTO' function that sets the feeding current automatically. Especially for Lithium batteries, it can prevent the over-charging can lead to an explosion by users fault. Every program in the unit is controlled with mutual links and communication for every possible error so it introduces a maximum safety. These can be set at users option.

Special recharge plugsport for receiver, transmitter and igniter charger. And for frequently used charger port such as multi purpose crocodile pin etc.

It provides most convenient balance charge port for Lithium batteries, with separated 3,4,5,6 charge port, and external reverse connector.

High-power and high-performance circuit
It employs the circuit that has maximum output power of 50W. As a result it can charge or discharge up to 15 cells of NiCd/NiMH and 6 series of Lithium batteries with maximum current of 5.0A. Furthermore the cooling system is so efficient that can hold such a power without any trouble of running the CUP or the operating program.

Individual voltage balancer for Lithium batteries inside
It has an individual-cell-voltage balancer inside. This does not require any extra balancer separately when charging Lithium batteries (Lilo/LiPO/LiFe) for cell voltage balancing.

Balance individual cells on discharge
It also can monitor and balance individual cells of the Lithium battery pack during the discharge process. If the voltage of any one cell varies abnormally, the process will be stopped with the error message.

Accept various types of Lithium battery
It can accept three types of Lithium batteries - Lilo, LiPo and LiFe. They have different characteristics by their chemistry. You can select any one of them that you are going to process before the job. For their specifications, refer 'Warnings and safety notes' section.

Lithium battery 'Fast' and 'Storage' mode

You can charge Lithium battery for special purposes. 'Fast' charge reduces the charging time of Lithium battery and 'storage' mode controls the final voltage of the battery to be suit for long time storage.

Maximum safety
Delta-peak sensitivity: The automatic charge termination program works on the principle of the Delta-peak voltage detection. (NiCd/NiMH)

Auto-charge current limit: When charging NiCd or NiMH at 'AUTO' current mode, you can set the upper limit of change current to avoid from high current charging. This is very useful when charging the low impedance and small capacity NiMH battery in 'AUTO' mode.

Capacity limit: The changing capacity always calculated by multiple of the charging current and time. If the charging capacity exceeds the limit the process will be terminated automatically when you set the maximum value.

Processing time limit: you can also restrain the maximum process time to prevent form any possible defect.

Input power monitor: To protect the car battery using as input power from being damaged the voltage of it always monitored. If it drops below the lower limit the process will be ended automatically.

Automatic cooling fan: The electric cooling fan comes into action automatically only when the internal temperature of the unit is raised.

Data store / load
For users convenience it can store maximum 5 data of different batteries. You can establish the data contains program setting of the battery to charge or discharge continually. These data can be called out at any time you need and the process can be executed without program setting.

Cyclic charging / discharging
Perform 1 to 5 cycles of charge>discharge or discharge>charge continually for battery refreshing and balancing.

PC based analysis using USB communication
For technical expert, it offers PC based program can analyze the characteristic of the battery by USB port. It shows a graph of voltage, current, capacity and temperature curves. It also shows the individual voltage of each cell in the Lithium battery pack.



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Friday, August 28, 2009

My recommend Battery Charger (1)

This charger is computerized with a high performance microprocessor and specialized operating software. It can maintain your battery at its best condition and also control them safely. Please read this entire operating manual completely and attentively as it contains a wide of information you need to keep the manual in a safe place and be sure to pass it on to the new owner if you ever dispose of yours imax B5.

Specifications

Features
Cell Balance and Charger in 1
The iMAX B5 Balance Charger has an individual-cell-voltage balancer built in so it does not need a separate balancer when charging Lipo batteries.

Maximum Safety
The automatic charge termination program works on the principle of the Delta-peak voltage detection.

Capacity Limit
The charging capacity is calculated by multiple of the charging current and time. If the charging capacity exceeds the limit the process will be terminated automatically when you set the maximum value.

Charge Time Limit
You can also set a maximum charge time to prevent any possible over charge.

Input Power Monitor
This function monitors the input voltage from your battery supply and will automatically stop the charge program if your battery falls below the required level.

High Power and High Performance Circuit
The iMax B5 Balance Charger has a maximun output power of 50W. As a result it can charge up to 14 cells of Nicd/NiMh and 5 series of Li-polymer batteries with maximum current of 5A.

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Thursday, August 27, 2009

Recommend battery chargers

My friend is planning to buy a Li-polymer Battery balance charger. But he does not know choose which one is better. His intention is to get a reasonably good charger with sufficient function to take good care of the Li-polymer Battery.

He ask me what is my suggestion. I recommend two Battery balance chargers for him to choose.







I will discuss this two Battery balance chargers in next time ~bye


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Wednesday, August 26, 2009

knowledge of Li-polymer Battery (2/2)

Storage temperature and charge of Li-polymer Battery

Storing a Li-Po battery at the correct temperature and charge makes all the difference in maintaining its storage capacity. The following table shows the amount of permanent capacity loss that will occur after storage at a given charge level and temperature.

It is significantly beneficial to avoid storing a Li-Po battery at full charge. A Li-Po battery stored at 40% charge will last many times longer than one stored at 100% charge, particularly at higher temperatures.

If a Li-Po battery is stored with too low a charge, there is a risk of allowing the charge to drop below the battery's low-voltage threshold, resulting in an unrecoverably dead battery. Once the charge has dropped to this level, recharging it can be dangerous. An internal safety circuit will therefore open to prevent charging, and the battery will be for all practical purposes dead.

In circumstances where a second Li-Po battery is available for a given device, it is recommended that the unused battery be discharged to 40% and placed in the refrigerator or freezer to prolong its shelf life. Batteries should be allowed to completely warm to room temperature over up to 24 hours before any discharge or charge.

Permanent Capacity Loss versus Storage Conditions

Storage Temperature

40% Charge

100% Charge

0 °C (32 °F)

2% loss after 1 year

6% loss after 1 year

25 °C (77 °F)

4% loss after 1 year

20% loss after 1 year

40 °C (104 °F)

15% loss after 1 year

35% loss after 1 year

60 °C (140 °F)

25% loss after 1 year

40% loss after 3 months



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Tuesday, August 25, 2009

knowledge of Li-polymer Battery (1/2)

Serious Safety Issues of Li-polymer Battery

If LiPo batteries are improperly charged they can cause an explosive fireball. We cannot over-emphasize the importance of using a charger specifically designed to charge LiPo batteries, and to be positive that the manual cell count (if the charger has one) is correctly set for the specific battery being charged. If you use a good quality LiPo charger, these batteries are totally safe.

LiPo Do's and Don'ts

Do: Only use a charger that is specifically designed to charge LiPo batteries. Using other types of chargers can cause an extreme fire hazard!

Do: LiPos don't develop memory or voltage depression characteristics like Ni-Cds. Do charge them without the worry of cycling or discharging them.

Do: Store LiPos at least partially charged. LiPos will maintain their performance levels over time, even during non-use, much better than Ni-Cds and there's no need to cycle them.

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Don't: Use any type of charger that is not specifically designed to charge LiPo batteries. Using non-LiPo-specific chargers can cause an extreme fire hazard!

Don't: Fully discharge your LiPo battery pack. Most speed controller have a voltage cut off that will prevent over-discharging the battery. Discharging a LiPo beyond it's critical minimum voltage will cause damage to the battery.

Don't:
If you have a crash and the battery is damaged, don't put the battery in your car or house immediately after a crash. It's possible that a chemical reaction can take place in the damaged battery that could cause a fire. Put the battery in a safe place for a least one hour.

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