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why does a good charged battery fail?

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Old 01-11-2018, 09:43 PM
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suzonka
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Default why does a good charged battery fail?

why do some RC lipo battery's charge good ,hold a charge yet when you fly your RC plane they die quick?

I use a 2S 7.4 volt 1300mah battery that came with my drone and the battery isn't swollen , looks, good yet will only fly the drone for 2 minutes, a good battery that I also have fly's the drone for 6-7 minutes
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Old 01-12-2018, 03:06 AM
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battery connection... either on the mainboard or the plugs ... are two area to look at.... the connection at the board maybe weak.. the plugs do get wear on them as well...
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Old 01-12-2018, 04:46 AM
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Cheaply made battery packs.
Could be the plug but more than likely it is the quality of the soldering of the bridge and the cheap cells used. Internal resistance can rise very quickly in these cheap cells and when it does the pack will not perform as it should. Internal resistance is not something you can see without using a charger that can read the internal resistance of a Lixx pack.
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Old 01-12-2018, 09:03 AM
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Just because a voltmeter says the battery is at full charge voltage does not mean it is a good battery. Put a load on it (such as the motors) and it dies quickly. New batteries can and do fail and it is not limited to LiPo's. Car batteries can do this as well. I think you have a bad battery, especially if another battery works normally in your quad.
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Old 01-12-2018, 10:27 AM
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How old is the pack? Older LiPos can look fully charged and still die out quickly. And life is not measured by how long you have had it but more by how many times you have recharged it.
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Old 01-13-2018, 04:20 AM
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Originally Posted by rgburrill View Post
How old is the pack? Older LiPos can look fully charged and still die out quickly. And life is not measured by how long you have had it but more by how many times you have recharged it.
+1, and how you have charged it .

I treat my LiPo batteries pretty good, and hardly ever go above a 1C charge rate. Not to mention picking out a proper "C" rated pack for RC/motor application is just as important. Just because a LiPo battery is included in a RTR package doesn't mean it's the optimal battery.

Last edited by RustyUs; 01-13-2018 at 04:28 AM.
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Old 01-14-2018, 03:06 PM
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Internal Resistance is most likely the culprit. As the packs go through cycles their internal resistance (IR) increases which is an indication of degradation of the battery. A good charger can give you an indication what your baseline is when you get a new battery. You can monitor the IR over time and have and idea of the overall "health" of your battery. Connectors as mentioned above also could be a culprit of short run times.

Keeping the LiPo at a storage charge (around 3.85v/cell) when not using helps to keep the IRs low. Storing the Lipo fully charged degrades the battery over time thus increasing IR. Not discharging the battery more then 80% of its capacity improves longevity. Heat is another enemy of the LiPo whether stored or running hard. Another thing to look at when charging keep an eye on each cell. A cell or two can go bad in a pack, bringing down the "health" of your battery and effect run times. Some chargers, when not using balance charging will overcharge a good cell(s) to satisfy the overall voltage (based on cell count) of the battery by compensating for the bad cell. This is dangerous (think fire) and can also kill battery run-times.

Usually a battery that has been designed for high discharge (low IR) such as a 25c (or above) battery can generally be charged above 1C with a good balance charger that monitors each cell. My 6 cell 5000mAh cells I regularly charge at 20 Amps safely. That's 4C and I have documented 300 cycles with 1miliohm change in IR. These cells are used in my 6000W 12 cell EDF jet.

Please note that the above is based on my experience of LiPo batteries and there are many other factors that can effect performance of batteries.
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Old 01-15-2018, 12:25 AM
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May be it is just not a suitable battery for your drone.
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Old 01-22-2018, 07:17 PM
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Default ​​​​​​​lipo bad shows good

Originally Posted by DrV View Post
Internal Resistance is most likely the culprit. As the packs go through cycles their internal resistance (IR) increases which is an indication of degradation of the battery. A good charger can give you an indication what your baseline is when you get a new battery. You can monitor the IR over time and have and idea of the overall "health" of your battery. Connectors as mentioned above also could be a culprit of short run times.

Keeping the LiPo at a storage charge (around 3.85v/cell) when not using helps to keep the IRs low. Storing the Lipo fully charged degrades the battery over time thus increasing IR. Not discharging the battery more then 80% of its capacity improves longevity. Heat is another enemy of the LiPo whether stored or running hard. Another thing to look at when charging keep an eye on each cell. A cell or two can go bad in a pack, bringing down the "health" of your battery and effect run times. Some chargers, when not using balance charging will overcharge a good cell(s) to satisfy the overall voltage (based on cell count) of the battery by compensating for the bad cell. This is dangerous (think fire) and can also kill battery run-times.

Usually a battery that has been designed for high discharge (low IR) such as a 25c (or above) battery can generally be charged above 1C with a good balance charger that monitors each cell. My 6 cell 5000mAh cells I regularly charge at 20 Amps safely. That's 4C and I have documented 300 cycles with 1miliohm change in IR. These cells are used in my 6000W 12 cell EDF jet.

Please note that the above is based on my experience of LiPo batteries and there are many other factors that can effect performance of batteries.
thank you.
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Old 03-30-2018, 01:44 AM
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Default battery failer in drone

Originally Posted by mushia View Post
May be it is just not a suitable battery for your drone.
could it be that being the c rating on the drones good batery that comes with it is not marked , that its a high C rating and the batteries I have are only 20C
yet in my airplanes with one motor they all work fine. ?
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Old 03-30-2018, 02:25 PM
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Default battery's die

Originally Posted by Mgfiest View Post
battery connection... either on the mainboard or the plugs ... are two area to look at.... the connection at the board maybe weak.. the plugs do get wear on them as well...
batte

The thing that is a mystery is when I hook up the original world tech battery and push it its slot inside the drone ,it works even outside the drone with Velcro it still works, I just shortened the connector adapter I made up and used new connectors on the ends and it still dont work with a known good battery that works in my RC airplanes/ hmmm
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Old 03-30-2018, 02:27 PM
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Default battery's tried died

Originally Posted by DrV View Post
Internal Resistance is most likely the culprit. As the packs go through cycles their internal resistance (IR) increases which is an indication of degradation of the battery. A good charger can give you an indication what your baseline is when you get a new battery. You can monitor the IR over time and have and idea of the overall "health" of your battery. Connectors as mentioned above also could be a culprit of short run times.

Keeping the LiPo at a storage charge (around 3.85v/cell) when not using helps to keep the IRs low. Storing the Lipo fully charged degrades the battery over time thus increasing IR. Not discharging the battery more then 80% of its capacity improves longevity. Heat is another enemy of the LiPo whether stored or running hard. Another thing to look at when charging keep an eye on each cell. A cell or two can go bad in a pack, bringing down the "health" of your battery and effect run times. Some chargers, when not using balance charging will overcharge a good cell(s) to satisfy the overall voltage (based on cell count) of the battery by compensating for the bad cell. This is dangerous (think fire) and can also kill battery run-times.

Usually a battery that has been designed for high discharge (low IR) such as a 25c (or above) battery can generally be charged above 1C with a good balance charger that monitors each cell. My 6 cell 5000mAh cells I regularly charge at 20 Amps safely. That's 4C and I have documented 300 cycles with 1miliohm change in IR. These cells are used in my 6000W 12 cell EDF jet.

Please note that the above is based on my experience of LiPo batteries and there are many other factors that can effect performance of batteries.
battery's tried died

The thing that is a mystery is when I hook up the original world tech battery and push it its slot inside the drone ,it works even outside the drone with Velcro it still works, I just shortened the connector adapter I made up and used new connectors on the ends and it still dont work with a known good battery that works in my RC airplanes/ hmmm
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Old 03-30-2018, 03:17 PM
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Trying to read and make sense of some of these posts is turning into a mystery !
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Old 03-31-2018, 02:29 AM
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High ir is a major cause .. false C rate is another . how you use and store battery
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