Friday, December 3, 2010

Get the Most for Your Hobby Dollars - How To Get Best Results from your RC LiPO Battery Packs

I know how exciting it is to receive a shipment of new RC products - and how great the temptation can be to rush out and try them immediately. But I've learned (yes, sometimes the hard way), that to get the best value for my money, protect my RC products and personal safety, it is smart to cool my jets a bit and take the time to read the safety and use guidelines first. This is especially true when it comes to LiPo batteries.

Here are some Guidelines on Safety, How to Break In a New LiPo Battery Pack, Charging, Discharging, Storage Charge and Disposal.

Safety Guidelines

1. Always use a charger specifically designed for Lithium Polymer batteries. Never use NiCD or NiMH type chargers to charge LiPO batteries. Failure to do so will damage the batteries and may cause fire and personal injury.
2. Always charge batteries in a fire proof container. Do not charge batteries on wood, cloth, carpet, in your model, or on any other flammable material. Have a chemical fire extinguisher near by in case of fire.
3. Never leave batteries unattended while charging. Always observe batteries when charging so that you can react to any problems that may occur.
4. If a battery is deformed, swollen or appears damaged, DO NOT CHARGE. Follow the disposal instructions below to properly and safely dispose the battery.
5. Any time you have an accident with your model or if the battery swells “balloons” or if the battery exceeds temperature guidelines, follow these safety steps:

a. Immediately remove the battery pack from your model or charger.
b. Place the battery in a non-flammable, well ventilated area.
c. Observe the battery for 30 minutes from a safe distance.
d. After 30 minutes, if the pack appears stable, is not swollen and does not show any signs of damage, return the battery pack to normal use with caution.

6. Do not allow exposed battery wires to touch each other. This may cause the battery to short and potentially cause a fire.
7. Store your batteries in a cool, dry place between 40-80 Fº / 4-26 Cº.
8. Do not assemble unmatched or dissimilar LiPO cells.
9. Store battery packs out of the reach of children and pets.

Charging Instructions

1. Venom Lithium Polymer Power Cells and the other LiPo battery packs with more than a single cell that we carry, feature a separate balancing plug that isolates each cell in a pack and charges it independently. This ensures that all cells peak equally and discharge at the same rate during use. Refer to the instructions that came with the battery pack regarding how to identify the balancing plug.
2. Charge each battery pack individually. Never charge battery packs in series. Charging packs in series may result in improper charger cell recognition and an improper charging rate that may lead to overcharging, cell damage and fire. We recommend using the Venom Pro Charger™ when charging your LiPO batteries. The Venom Pro Charger™ is designed to automatically peak charge individual pack cells (up to 6 cell packs) with convenience and ease. We carry the Pro Charger, the Pro Charger Plus and they are available in versions with power supply and without power supply.
3. Always check to make sure that your charger settings match those listed on the battery pack label. Refer to the battery label for the proper cell count and charging amperage setting. Selecting a cell count or amperage charge rate other than the one listed on the battery pack will damage the battery and may cause a fire.
4. Make sure the battery connections are connected in the correct polarity. A wrong connection will damage the battery and may cause a fire.
5. Always check battery pack voltage before charging. Do not discharge LiPO batteries below 3.0 Volts per cell. The voltage of a typical LiPO cell at rest is 3.7 Volts. If the battery pack appears swollen or damaged, DO NOT attempt to charge it. Check the voltage and follow Step 5 from the Safety Guidelines section.
6. Do not charge at over 1C current. C= battery pack mAh capacity ÷ 1000. Divide the battery mAh capacity by 1,000 to determine the proper charge rate. 

Example:  1200mah ÷ 1000 = 1.20 Amps

Charge Rate for Venom Power LiPO Battery Packs, example:
a. 800mah Capacity = 0.80 Amps
b. 1200mah Capacity = 1.20 Amps
c. 2000mah Capacity = 2.00 Amps

Some packs will let you charge at greater than 1C, but you'll shorten their overall lifespan if you do.

7. Do not peak charge to more than 4.2 Volts per cell. Example: A 2S Battery Pack contains two cells, therefore the peak voltage should not exceed 8.4 Volts.
8. Battery Temperature is critical. Please use the following guidelines:

a. Charge Temp Range: 32 - 110Fº / 0-43Cº
b. Discharge Temp Range: 32 - 140Fº / 0-60Cº
c. Storage Temp Range: 40 - 80Fº / 4-26Cº

For optimum performance in cold climates, warm the pack to 100Fº/ 37Cº before use.

9. If the battery exceeds the temperature guidelines as above, isolate the battery pack and follow Step 5 from the Guidelines and Warnings section.

Breaking-In a New Battery

1. New LiPO battery packs may require 12 or more charge/discharge cycles before the battery’s optimum performance is reached.
2. During this time, it is recommended that the battery pack is not discharged over 7C. 7C = 7 x 1C, where 1C= battery pack mAh capacity ÷ 1000. Example: [(1250mAh ÷ 1000) x 7] = 8.75 Amps

Recommended Maximum Discharge Rates During Break-In Period:
a. 800mah Capacity = 5.4 Amps
b. 1200mah Capacity = 8.4 Amps
c. 2000mah Capacity = 14 Amps

Discharging Instructions

1. Never discharge a LiPO battery pack at more than the manufacturer’s recommended discharge rate. The discharge rate is:
Battery pack capacity (mah) ÷ 1000 x Pack C rating
Example for 15c packs: (3200mah ÷ 1000) x 15c = 48 Amps
Example for 20c packs: (2100mah ÷ 1000) x 20c = 42 Amps

If your speed control's low power shut-off has kicked in, don't reset it. The shut-off usually means your battery is at the low end of its voltage, and if you reset, you could cause it to drop below the recommended discharge rate, and damage your battery pack.

Storage Charge

If you are not going to use the battery pack for longer than one month, charge the pack with a storage charge. The cells will stay in balance longer and the pack will only lose a slight amount of voltage.

Battery Disposal Instructions

1. Discharge battery pack to 2.5 Volts per cell or less.
2. Fill a bucket with enough water to submerge the battery pack completely.
3. Add salt to the water until no more salt will dissolve; the water is now saturated with salt.
4. Place the battery pack in the bucket and leave submerged in the salt water solution for 24 hours.
5. Remove the battery pack from the salt water and test the voltage.
6. If the voltage does not read 0.0 Volts, re-submerge and re-test until the voltage reads 0.0 Volts.
7. Once the battery pack has been discharged to 0.0 Volts, it is safe to dispose.

It's Quick and Easy to safely dispose of your old rechargeable batteries: has developed a nationwide free battery (and cell phone) drop-off and collection program. Click the link below and enter your zip code to find locations of stores & businesses where you can drop off your old rechargeable batteries for safe disposal and recycling: Battery-Drop-off-Locations-Near-You  When we enter our zip, dozens of nearby businesses pop up. Give it a Try!

What's been your experience with LiPo's?  What's your favorite power source?  Would love to hear from you.

Here's a link to the RC Batteries Chargers and Power Supplies on my website.  Thanks for shopping at RC Planes and Copters!

Until next time, keep it safe and keep it flying!

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