| LiPo Do's and Don'ts | | | | get it clear of all other items and be prepared for |
| There is a lot of confusion about LiPo batteries out | | | | flame to come out! If after many hours have passed |
| there especially after problems where they have | | | | (days) and the pack is still ballooned but have not |
| caught fire. This is mainly because of people that do | | | | combusted, discharge the pack slowly and dispose of |
| not have a clear understand of how to work with LiPo | | | | it in a proper way. |
| batteries and the do's and don'ts. Hopefully some of | | | | 9. If you have a crash with your lithium cells they may |
| these tips will help people in the right direction. | | | | be damaged internally! The pack may look fine but |
| LiPo batteries are big in the world of rc planes, rc jets | | | | may only balloon in time. If you have crashed, carefully |
| and radio controlled models in general, where the | | | | remove the battery pack from the model and watch it |
| advantages of both lower weight and greatly | | | | carefully for at least the next 30 minutes. Ensure the |
| increased run times can be sufficient justification for | | | | pack is cool to touch before transporting it. |
| the price for the rc hobby. However, lithium | | | | 10. Charge your batteries in an open well ventilated |
| polymer-specific chargers are required to avoid fire | | | | area. If a battery does become unstable you want the |
| and explosion. Fire can also occur if the battery is | | | | hazardous fumes and material to be vented from the |
| short-circuited, as tremendous current passes through | | | | room. |
| the cell in an instant. Radio-control enthusiasts must | | | | 11. Keep a bucket of sand nearby when you are flying |
| take special precautions to ensure their battery leads | | | | or charging batteries. This is a cost effective way to |
| are properly connected and insulated. Furthermore | | | | extinguish fires. |
| fires can occur if the cell or pack is punctured. | | | | 12. Do not think it won't happen to you! Safety is no |
| Using LiPo's properly and charging them correctly is no | | | | accident! |
| trivial task. There are many things to consider before | | | | Some useful tips for keeping your LiPos healthy: |
| using lithium cells for e-flight. But none is more important | | | | 1. Let your packs cool down before recharging. It is |
| than safety! | | | | very important to the internal chemical composition of |
| Safety is IMPORTANT! | | | | the cells not to run hot or worse be hot when charging |
| Until you are willing to follow all safety precautions, DO | | | | as only more energy and heat is being put back into |
| NOT use lithium batteries. If prefer just to just plug in a | | | | the cells. So wait 30min to 1hour before charging your |
| battery and not worry about it, run it flat, charge it hot | | | | packs again. |
| then LiPo technology is not for you! | | | | 2. Stick to the 80% rule! This basically means never |
| Lithium cells must be charged very differently than | | | | push more than 805 of its discharge rate and drain |
| NiCD or NiMH cells. Firstly they require a special | | | | more than 80% of the capacity of your LiPo battery |
| charger specifically designed to charge lithium cells, | | | | pack. When one drains more than 80% the capacity it |
| NEVER use NiCD or NIMH only chargers on LiPo | | | | starts to cause allot internal heating in the cell and |
| batteries! You must use a Lithium Ion or Lithium | | | | basically start eating away at itself. So basically if you |
| Polymer charger that is designed to handle the number | | | | have a 2200mah pack, you want to only put back |
| of cells you are trying to charge. Charging Lithium cells | | | | 1760mah when charging. Most chargers display the |
| is the most hazardous part of using lithium batteries. | | | | number of mah on a charge so you can adjust your |
| EXTREME care must be taken when charging them | | | | flight time, gearing, etc based on this figure to make |
| to avoid damaging the cells or worse causing them to | | | | your LiPos last longer. |
| catch fire. It is important to set your charger to the | | | | 3. Discharge your packs to storage levels if you not |
| correct voltage or cell count. There have been fires | | | | going to use them within a week or two of the last |
| directly caused by lithium batteries so PLEASE BE | | | | charge. This will help make packs last longer especially |
| RESPONSIBLE when charging lithium batteries. | | | | if you don't fly every week. If you leave LiPos fully |
| Here are some IMPORTANT guidelines when using | | | | charge for long periods it start causing deterioration |
| LiPo batteries: | | | | internally to the cell. Most new chargers have storage |
| 1. Only use a charger approved for lithium batteries! | | | | discharge options these days for this reason. If yours |
| You should clearly see Li-Po, Li-Ion marked on the | | | | does not have this option simply discharge to between |
| charger or specified in the operations manual of the | | | | 3.8 to 3.9volts per cell. Then you can store them in a |
| charger. Both batteries are charged in exactly the | | | | safe place. Some people also refrigerate their packs |
| same manner. | | | | when in storage. |
| 2. Make sure you set the correct cell count on your | | | | 4. Break-In (Cycle-In) your LiPo! LiPos don't really need |
| charger. This is important as it depicts the total voltage | | | | a break in period as such like a Nitro motor but they do |
| for the pack. Ensure that charger displays the correct | | | | require a few cycles to reach their full power potential. |
| cell count when you start charging. If you don't know | | | | After a few charge/discharge cycles you get the |
| how to do that, consult your chargers manual or get a | | | | chemical reaction established in the pack and they do |
| charger that displays this information. Each cell must | | | | start performing a little better after this. So ideally a |
| never be charged to more than 4.2 volts. | | | | pack should by cycled 3-4 charges before you make |
| Overcharging a cell will cause the chemical | | | | use of the battery's full potential. There are several |
| composition of the Lithium to become unstable which | | | | ways to cycle your pack, simply charge/ discharge |
| could lead to flames coming from the cell. | | | | them on your LiPo charger. If you use them in your |
| 3. Balance charge your LiPos. Having an unbalanced | | | | helicopter you can do short 2-3min hover flights and |
| pack can cause damage to the cells if cells are not | | | | recharge. |
| within 0.1 volts of each other. Most proper LiPo | | | | How puffed is puffed? |
| chargers come with a balance option, if yours does | | | | When you get you LiPo packs the covering looks like it |
| not have it we strong suggest you get one. Depending | | | | have been vacuum sealed together. If after a number |
| on how much current you drawing from you LiPo | | | | to cycles they might develop a slight bit of air between |
| each flight you may want to balance your packs | | | | cells it probably not a total wreck. I mean we are |
| every 3-5 flights to ensure each cell is individually | | | | talking a millimetre or so then you can most likely |
| charged to 4.2 volts so that they are all equal. If after | | | | continue using them. Just monitor that it does not get |
| every flight the cell of the pack is unbalanced you may | | | | worse. If the battery is puffed up like a bicycles inner |
| have faulty cell. Balance the cells more frequently to | | | | tube then dispose of it. |
| see if you can correct the problem. If the problem | | | | How to dispose of a LiPo? |
| persists consider replacing the pack. | | | | There is a couple of suggested ways of disposing of |
| 4. NEVER leave your batteries charging unattended. | | | | LiPos. The most common one is to take a bucket and |
| This is the number one reason for house fires. If | | | | fill it with salt water mixture. The put the LiPo in the salt |
| something goes wrong you want to attend to it quickly! | | | | water with the idea that the salt water creates a low |
| 5. Charge your batteries on a surface that will not be | | | | conductive current to drain the LiPo battery. Secondly |
| damaged by fire. Should a LiPo catch fire you want to | | | | the salt water will seep into the cells and neutralize the |
| avoid the problem spreading to other surfaces. Vented | | | | chemical reaction. |
| fire safes, pyrex dishes with sand in the bottom, | | | | Fire risk? |
| fireplaces, plant pots, are all good options to consider. | | | | The most common reason for LiPo batteries to catch |
| The most practical solution today is to purchase LiPo | | | | fire is because of improper charging. Whether it is |
| safe bags for charging. | | | | using the incorrect charging, wrong cell count setting on |
| 6. NEVER CHARGE AT MORE THAN 1C unless the | | | | the charger or charging the cells to over 4.2volts each. |
| battery pack vendor has explicitly proven it is safe to | | | | What happens at this point is the chemicals stay going |
| do so. Keep it at less than or equal to 1C of the | | | | into a thermal overload failure and start heating up, |
| battery's capacity rating if you are unsure. Many LiPo | | | | causing hydrogen gas to be emitted which cause it to |
| related fires are due to people charging at a greater | | | | puff to the point of fracture where then it vents fire. |
| current than what the LiPo is rated to be able to | | | | Best solution here is to buy some LiPo-safe charging |
| handle. The concept of fast charge should never be | | | | bags to do your charging in or store potentially fragile |
| applied to LiPos! | | | | packs. |
| 7. Never discharge your LiPo cells to less than 3.3volts | | | | Secondly you never want to short the cells or |
| per cell, not the total pack voltage. Most ESC's today | | | | puncture the casing as will also cause the chemical |
| will do a soft cut-off at 3.3volts per cell and a hard | | | | reaction explained above and can cause a fire risk. |
| cut-off at 3.0volts per cell. However some will not give | | | | LiPos won't just combust in storage unless there is |
| you and warning. Best advice is to fly with a timer and | | | | some damage to the pack externally or internally. |
| monitor the voltage and adjust your flying time if needs | | | | Therefore if you take care charging and using your |
| be. | | | | packs you should have no problems. |
| 8. NEVER puncture the cell, ever! If a cell balloons | | | | Hope this helps people understanding how to work |
| rapidly place it in a fire safe place immediately. If this | | | | with LiPos. If you follow these guides you should have |
| happens and smoke and heat is coming from the LiPo | | | | good success with LiPos and enjoy the RC Hobby. |