Investing in batteries for your multirotor can be an expensive proposition, and one that can be ruined by not properly caring for them.\u00a0 Lithium polymer batteries are some of the most powerful batteries available but are also some of the most sensitive.\u00a0 They definitely have a finite life span, making them one of the consumable components in the hobby.\u00a0 Following proper FPV battery maintenance, you can make your investment last, and keep your batteries performing at their maximum.<\/p>\n
If you are new to FPV, and are looking for more great information on batteries, refer to our All About Multirotor Drone Batteries<\/a> article for more great information![vc_row][vc_column][vc_single_image image=”1594″ img_size=”full” alignment=”center” onclick=”link_image”][\/vc_column][vc_row][\/vc_row][vc_column][vc_column_text]<\/p>\n Lithium polymer (LiPo) batteries are a great choice for model aircraft for a few different reasons.\u00a0 Based on their chemical makeup, they are among the most powerful batteries by weight that exist.\u00a0 They are particularly energy dense, and have the capacity for delivery that power extremely quickly on demand.\u00a0 LiPo batteries use a few different components to create a charge that you can use.\u00a0 Understanding that structure is key to understanding how to properly perform FPV battery maintenance.<\/p>\n LiPo batteries use a series of alternating structures that facilitate the transition of electrons from one layer to the next.\u00a0 These layers, the cathode and anode create a pathway for charge to flow.\u00a0 The cathodes use aluminum and is coated in an oxidizing lithium material. \u00a0The anodes use a copper material along with a carbon material, such as graphite.\u00a0 The anodes and cathodes alternate between a micro porous polymer membrane, the separator.\u00a0 The entire structure is suspended in a lithium gel electrolyte.\u00a0 Lithium itself is highly reactive to both air and water, and when the battery has a puncture or cut, can cause a fire.<\/p>\n When a battery is charged, the cathode passes lithium ions through the electrolyte and separator, to the anode, where they are stored for use.\u00a0 This gives your battery it\u2019s \u201ccharge\u201d.\u00a0 When discharging, the process is reversed; the anode passes the lithium ions back to the cathode, and that charge is pumped into your model for use by your electronics.[\/vc_column_text][\/vc_column][vc_row][vc_column][vc_column_text]<\/p>\n One of the primary indicators of battery heath is going to be the internal resistance of the battery.\u00a0 Generally measured in term of milliohms (m\u03a9)<\/strong>, the internal resistance of a battery determines how hard it is to pass the energy stored in the battery to the model aircraft.\u00a0 The higher the internal resistance, the harder it is to pass that energy.<\/p>\n During use of the battery, there are many things that can cause internal resistance to rise.\u00a0 When you deep discharge your battery (take it below the 80% discharge level), that can cause internal resistance to rise.\u00a0 Also, when pushing the battery to pump out maximum energy over an extended period of time, can affect internal resistance negatively.\u00a0 Batteries over time will naturally build up internal resistance.\u00a0 Lastly, excessive heat can also adversely affect internal resistance.\u00a0 When internal resistance becomes too high, there comes a point where the battery will stop delivering all the potential energy that it was originally capable of.\u00a0 At this point, you may need to remove the battery from service.<\/p>\n When selecting a charger, you may want to look for one that can measure internal resistance.\u00a0 In this way, you can be up to date on the health of your batteries.\u00a0 If your charger does not monitor internal resistance, there are devices out there, called ESR meters that you can use.<\/p>\n Internal resistance is one the primary concerns when we are discussing FPV battery maintenance.\u00a0 When you don\u2019t take the time and care with your batteries, their life span, and your investment, will be cut short.\u00a0 Believe me, I have experienced this firsthand.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column][vc_single_image image=”1604″ img_size=”full” alignment=”center” onclick=”link_image”][\/vc_column][\/vc_row][vc_row][vc_column][vc_column_text]<\/p>\n Proper charging protocols are the beginning of excellent FPV battery maintenance.\u00a0 When charging your batteries you want to take a few things into consideration.\u00a0 First, would be the capacity of your battery.\u00a0 Capacity is defined by how much charge your battery can both store, and deliver, and is rated in amp hours, or Ah.\u00a0 Because of the size of our batteries, that is often reduced to milliamp hours, or mAh.\u00a0 One of the most common capacities in use for multirotors would be the 1300 mAh battery, and as such will be the one that we will be using for our example.<\/p>\n When determining the proper amperage to charge a battery, one will directly reference the capacity.\u00a0 You will often here pilots talk about what \u201cC\u201d they charge their batteries at.\u00a0 You can determine \u201cC\u201d rating in amps by using the following equation; cA = mAh \/ 1000.\u00a0 In the example of our 1300 mAh battery, this equates to 1.3 amps.\u00a0 So now, when someone talks about charging their 1300 mAh battery at 2C, you can calculate that out to be 2.6 amps, using this equation; 2(cA) = (1300 mAh \/ 1000).<\/p>\n Most batteries will alert you to the maximum rate that you can safely charge your batteries at, either on the battery, or with the included documentation.\u00a0 For example, the Lumenier Batteries<\/a> are rated at a maximum of 5C charge rate.\u00a0 Now, the question is, does that mean that you should always charge your battery at this rate?\u00a0 Absolutely not!\u00a0 Charging a battery at that rate will accelerate the decay of the battery, and raise your internal resistance quicker. \u00a0Charging batteries is similar to creating good barbeque; low and slow.\u00a0 The recommended charge rate for any battery is going to be 1C. Charging at 2C should be the highest you go, and only if you are in a hurry.<\/p>\n On a safety note, never leave your charging batteries unattended.\u00a0 The hobby is rife with examples of LiPo fires taking out a pilots gear, garage, or entire home.\u00a0 Even with someone paying attention, these things can happen, but by being around your batteries when charging, you can react to a situation much quicker.\u00a0 Proper FPV battery maintenance always starts with good safety practices.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column width=”1\/6″][\/vc_column][vc_column width=”2\/3″][vc_single_image image=”1597″ img_size=”full” alignment=”center” onclick=”link_image”][\/vc_column][vc_column width=”1\/6″][\/vc_column][\/vc_row][vc_row][vc_column][vc_column_text]<\/p>\n Parallel charging can be a way to get several batteries charging at once, but use with caution.\u00a0 The way parallel charging works is by using a charging board specially designed to accomplish this task.\u00a0 When several batteries are hooked up to the board, the charger sees them as one large battery.\u00a0 In order to charge these batteries at the same rate as you would a single battery, you need to do a little more math.\u00a0 In our example, we are going to use the 1300 mAh battery again, and we are going to charge six of them together using a parallel board.\u00a0 Using this equation, we can determine what 1C is; cA=6(1300 mAh \/ 1000). \u00a0From this equation, we get 7.8 amps.\u00a0 Now if we wanted to charge at 2C, it would look like this 2(cA) = 6(1300 mAh \/ 1000), resulting in 15.6 amps.<\/p>\n There are three things to consider about parallel charging when considering proper FPV battery maintenance.\u00a0 Firstly, never charge batteries that have a different number of cells together.\u00a0 For example, do not charge 3S batteries with 4S batteries. \u00a0Doing so will damage your batteries, might damage your charger, and may start a LiPo fire, which we should avoid.<\/p>\n Secondly, batteries that are to charge together need to have very similar voltages.\u00a0 Optimally, they need to be within .10 volts from each other.\u00a0 If they are not, you may need to \u201cbump\u201d charge them to get them within that range.\u00a0 Not heeding this advice can lead to batteries with a higher charge dumping that charge into the lower charged batteries and a very fast rate, damaging both.<\/p>\n Lastly, and most important, internal resistance rears its ugly head here. Think of internal resistance as a virus that infects your batteries.\u00a0 That virus can “transmit\u201d to your other batteries through the parallel charging process.\u00a0 So if you have a bad battery, and you charge it together with other batteries, you can corrupt all the other batteries.<\/p>\n I\u2019m not going to tell you not to parallel charge, but ultimately if you want to make sure you don\u2019t corrupt your batteries, or don\u2019t want to have worry about matching voltages, you may want to look into a multiport charger.\u00a0 It\u2019s truly the safest option out there.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column][vc_column_text]<\/p>\n Alright, so we have our batteries charged, now we get to go out and rip with abandon right?\u00a0 Not so fast there, Sparky!\u00a0 Discharging your batteries through the use of them on your model is where the most damage to your battery can, and will, occur, and is the place where we absolutely must practice proper FPV battery maintenance.<\/p>\n First off, never discharge your batteries completely.\u00a0 This will cause your batteries to heat up to levels that are out of specifications for the battery.\u00a0 Remember, excessive heat builds up internal resistance.\u00a0 The maximum that a battery should discharge to is 80% of the total capacity.\u00a0 So in the case of our 1300 mAh battery, that equates to 1040 mAh drawn out.\u00a0 Additionally, never discharge any individual cell below 3.0 volts.\u00a0 In a 4S battery, using this standard, overall voltage should not come to a resting state below 12 volts (3 volts X 4 cells).\u00a0 Personally, I don\u2019t draw down my 4S batteries below 13.8 volts.<\/p>\n Another cause of battery damage is drawing the battery down too quickly with long duration high throttle.\u00a0 Doing so will over tax the battery, again leading to high heat generation. \u00a0Keep your boosts of throttle relatively short, optimally less than ten seconds in duration.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column width=”1\/6″][\/vc_column][vc_column width=”2\/3″][vc_single_image image=”1596″ img_size=”full” alignment=”center” onclick=”link_image”][\/vc_column][vc_column width=”1\/6″][\/vc_column][\/vc_row][vc_row][vc_column][vc_column_text]<\/p>\n When it comes to discharging batteries through use in your model, you want to select one that will provide the appropriate amount of power.\u00a0 Selecting a battery that does not have the capability to discharge the power needed by your motors, will cause your model to be slow and not perform as expected.\u00a0 It will also overtax the battery, thus damaging it.\u00a0 Printed on the battery you will usually see two numbers; the lower number is the constant \u201cC\u201d rating, telling you how much power the battery will be able to deliver relatively consistently over the discharge cycle.\u00a0 The second number will give you the burst \u201cC\u201d rating, which is the amount of power the battery is capable of pushing out for short burst, usually up to ten seconds.<\/p>\n Batteries are rated for their discharge rate using the same equation that we used for the charge rate, and using that equation, you can select the appropriate battery for you model setup.\u00a0 Let\u2019s take a quick look at the Lumenier 1300mAh 4s 75c Lipo Battery<\/a>.\u00a0 This particular battery is rated at 75C continuous, and 150C burst.\u00a0 When we apply our equation, you get some true numbers in terms of amp draw that you can relate to your model, and we will calculate that out below.<\/p>\n C(mAh \/ 1000) = Amps Capability<\/p>\n So in the case of our 75C\/150C battery, that looks like this:<\/p>\n 75(1300 \/ 1000) = 97.5 Amps Continuous<\/p>\n 150(1300 \/ 1000) = 195 Amps Burst<\/p>\n That\u2019s a lot of power available for your motors to use, and would be a good option for a moderately high power build.\u00a0 However, let\u2019s look at a lower \u201cC\u201d rated battery, such as a 40C \/ 80C battery.<\/p>\n 40(1300 \/ 1000) = 52 Amps Continuous<\/p>\n 80(1300 \/ 1000) = 104 Amps Burst<\/p>\n Now this battery would not be good to use on that same high power build.\u00a0 The motors might draw more than 52 Amps just at a medium high throttle, and there are chances that you would damage the battery.\u00a0 Does this mean that you should always go for high \u201cC\u201d rated batteries?\u00a0 No, not at all.\u00a0 In fact, what it does mean, is that if you have a model that does not require a higher \u201cC\u201d rated battery, that you could select one that will work for your build, and potentially save some money.\u00a0 Higher \u201cC\u201d rated batteries are usually much more expensive than one that is lower.\u00a0 Selecting the right LiPo for the job is another way to exercise proper FPV battery maintenance.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column][vc_column_text]<\/p>\n The last thing we are going to cover for proper FPV battery maintenance is the correct storage of your batteries.\u00a0 When you get home from the field, one of the first things you should do is to set all your batteries to storage charge.\u00a0 This will put them at the nominal charge for being put away on the shelf, and ensure that they are ready for the next flight session.\u00a0 This also puts the battery in a stable state, in which the likelihood for damage and build-up of internal resistance is much less.<\/p>\n If you have fully charged batteries that you aren\u2019t going to use relatively quickly, such as the next day or so, then go ahead and discharge those to storage charge as well.\u00a0 Leaving a fully charged battery to sit for longer periods of time will cause some damage.\u00a0 Nominally, the voltage for should be around 3.8 volts per cell to be at storage.<\/p>\n This also gives you a chance to inspect each of your batteries for any damage after your flight session.\u00a0 You want to look for issues such as cut cables, damaged connectors, holes and punctures, and dents or bends in the individual cells.\u00a0 Any kind of damage needs to be assessed for both safety and viability of the battery, and a decision needs to be made if the battery can be still be put back into service after repairs.<\/p>\n Batteries are expensive, and without them, you aren\u2019t going to be flying much.\u00a0 Taking the time and effort into proper FPV battery maintenance will protect that investment, and keep you in the air.\u00a0 It also means that you won\u2019t need to replace bad batteries as often, saving you money for all the other things you want, like new models!\u00a0 These practices will also keep you, your family, and your things safe.\u00a0 Remember, LiPo\u2019s can be volatile when not properly cared for![\/vc_column_text][\/vc_column][\/vc_row]<\/p>\n","protected":false},"excerpt":{"rendered":" Investing in batteries for your multirotor can be an expensive proposition, and one that can be ruined by not properly caring for them.\u00a0 Lithium polymer batteries are some of the most powerful batteries available but are also some of the most sensitive.\u00a0 They definitely have a finite life span, making them one of the consumable … Read more<\/a><\/p>\n","protected":false},"author":2,"featured_media":1618,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[133],"tags":[1878,421,1681,418,742,1874,1876,1877,1873,1875],"class_list":["post-1591","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-fpv-essentials","tag-battery-safety","tag-drone","tag-drone-battery","tag-drone-racing","tag-fpv-drone-racing","tag-lipo-battery","tag-lipo-charging","tag-lipo-safety","tag-lithium-polymer","tag-lithium-polymer-battery-charging","infinite-scroll-item","generate-columns","tablet-grid-50","mobile-grid-100","grid-parent","grid-33"],"_links":{"self":[{"href":"https:\/\/www.getfpv.com\/learn\/wp-json\/wp\/v2\/posts\/1591","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.getfpv.com\/learn\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.getfpv.com\/learn\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.getfpv.com\/learn\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.getfpv.com\/learn\/wp-json\/wp\/v2\/comments?post=1591"}],"version-history":[{"count":17,"href":"https:\/\/www.getfpv.com\/learn\/wp-json\/wp\/v2\/posts\/1591\/revisions"}],"predecessor-version":[{"id":4681,"href":"https:\/\/www.getfpv.com\/learn\/wp-json\/wp\/v2\/posts\/1591\/revisions\/4681"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.getfpv.com\/learn\/wp-json\/wp\/v2\/media\/1618"}],"wp:attachment":[{"href":"https:\/\/www.getfpv.com\/learn\/wp-json\/wp\/v2\/media?parent=1591"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.getfpv.com\/learn\/wp-json\/wp\/v2\/categories?post=1591"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.getfpv.com\/learn\/wp-json\/wp\/v2\/tags?post=1591"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Structure of a Lithium Polymer Battery<\/h2>\n
Internal Resistance<\/h2>\n
Proper Charging<\/h2>\n
What Amp Setting to Use?<\/h3>\n
Don’t Walk Away!<\/h3>\n
Parallel Charging<\/h3>\n
The Do’s and Don’ts of Parallel Charging<\/h4>\n
Discharging Batteries<\/h2>\n
Choosing the Right Battery<\/h3>\n
Calculating Battery “C” Rate<\/h4>\n
Storage of Batteries<\/h2>\n
FPV Battery Maintenance keeps your Investment Healthy<\/h2>\n