I have been looking and can not find the Size of the Battery Pack, is it a single cell or multiple,
Tello Battery Pack
- Thread starter Dishnu
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It has a nominal voltage of 3.8 volts so it has just one cell.
The dimensions are : 62 x 25 x 9.5 mm
Jdbye
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Not necessarily, they could be connected in parallel.
But it's most likely a single cell as these types of batteries tend to be.
I am also looking to find out more about the batteries - I want to build my own charger for them and create a battery with higher capacity. I do not yet have my Tello (arriving later this month) but have already begun my research for modification on all sorts of things.
I have the following information so far;
Its an 1100mAh lipo battery with a voltage of 3.8V and has 4 pins.
Based on what we know so far, the pins are most likely power, temperature sensor and BSI.
On a device running a processor this advanced, I'd say BSI is absolutely necessary (check link below), and with names like Intel and DJI involved, there's almost definitely going to be a temp sensor. This is however still an assumption.
Otherwise, due to the idea that these four pins have been assigned as such, we can conclude that the battery is actually a single cell. This makes building a charger waaaaay easier.
Here's what I think the pinout might be;
1. Positive
2. ?? (BSI or BTEMP)
3. Negative
4. ?? (BSI or BTEMP)
Check out this video on an explanation of how these four pins work.
If anyone actually strips a battery, please post pictures. When I get my battery, I will heat it and look for changing resistance to identify BTEMP.
In order to create a battery with higher capacity that is also safe to use, we'll have to be able to replicate BSI. I have no idea how to do that. Otherwise, if you don't mind the (low) risk of damaging the firmware with an unplanned battery ejection, you could slap pretty much anything with a matched voltage on there and be fine.
I have the following information so far;
Its an 1100mAh lipo battery with a voltage of 3.8V and has 4 pins.
Based on what we know so far, the pins are most likely power, temperature sensor and BSI.
On a device running a processor this advanced, I'd say BSI is absolutely necessary (check link below), and with names like Intel and DJI involved, there's almost definitely going to be a temp sensor. This is however still an assumption.
Otherwise, due to the idea that these four pins have been assigned as such, we can conclude that the battery is actually a single cell. This makes building a charger waaaaay easier.
Here's what I think the pinout might be;
1. Positive
2. ?? (BSI or BTEMP)
3. Negative
4. ?? (BSI or BTEMP)
Check out this video on an explanation of how these four pins work.
If anyone actually strips a battery, please post pictures. When I get my battery, I will heat it and look for changing resistance to identify BTEMP.
In order to create a battery with higher capacity that is also safe to use, we'll have to be able to replicate BSI. I have no idea how to do that. Otherwise, if you don't mind the (low) risk of damaging the firmware with an unplanned battery ejection, you could slap pretty much anything with a matched voltage on there and be fine.
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I am also looking to find out more about the batteries - I want to build my own charger for them and create a battery with higher capacity. I do not yet have my Tello (arriving later this month) but have already begun my research for modification on all sorts of things.
I have the following information so far;
Its an 1100mAh lipo battery with a voltage of 3.8V and has 4 pins.
Based on what we know so far, the pins are most likely power, temperature sensor and BSI.
On a device running a processor this advanced, I'd say BSI is absolutely necessary (check link below), and with names like Intel and DJI involved, there's almost definitely going to be a temp sensor. This is however still an assumption.
Otherwise, due to the idea that these four pins have been assigned as such, we can conclude that the battery is actually a single cell. This makes building a charger waaaaay easier.
Here's what I think the pinout might be;
1. Positive
2. ?? (BSI or BTEMP)
3. Negative
4. ?? (BSI or BTEMP)
Check out this video on an explanation of how these four pins work.
If anyone actually strips a battery, please post pictures. When I get my battery, I will heat it and look for changing resistance to identify BTEMP.
In order to create a battery with higher capacity that is also safe to use, we'll have to be able to replicate BSI. I have no idea how to do that. Otherwise, if you don't mind the (low) risk of damaging the firmware with an unplanned battery ejection, you could slap pretty much anything with a matched voltage on there and be fine.
On Youtube there are several videos on connecting the lamps using the battery contacts. There is a video on the installation of an additional battery. Look, the authors are all talking about the battery.
Speaking of chargers, I was considering buying the DJI charger which costs about $17-20 (with tax + shipping). I just came across a cable which has USB on one end and a receptacle for the Tello battery on the other. It costs a total of $5 from AliExpress. Not the same as a 3 battery charger but at least I can charge my spare while using the Tello.
I found these pictures of Tello's battery ...
3.8V Lipo to a Cell. These are LiHV "High Voltage Lithium Polymer" batteries. It is similar to the LiPo battery but allows you to safely charge it up to 4.35 V per cell.
3.8V Lipo to a Cell. These are LiHV "High Voltage Lithium Polymer" batteries. It is similar to the LiPo battery but allows you to safely charge it up to 4.35 V per cell.
Guorium
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When I gently press the label side of tge battery, i see the sticker sink in some places revealing a grid pattern. It is the upside of the battery in the top picture you posted. However I see no grid there. Perhaps it is the structure of the black plastic casing? Got a picture of the casing?
Wow I didn't even know LiHV existed. That means we've got some leeway for the voltage cutoff on a potential charging circuit. Thanks for the pictures!
The place where I work has a dummy Tello on display with a dummy battery. Ill try and get some pics of that. It would be cool to 3d print the battery casing so the community can start playing around with different power cells.
I'm pretty sure the charger you're talking about does simultaneous charging. The original charging hub only does sequential charging. So I think you're in a win-win situation
Guorium
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Above the lid there are 8 holes (surely a safety in case the lipo swells).
I have no other photos, I can only tell you that the first and third pins are positive and negative.
Attachments
LiPo = max 4.20V/cella
LiHv = max 4.35V / cella
In addition, the higher voltage degenerates the batteries faster, and in fact (in general) LiHv have a shorter life than normal LiPo.
Measure the voltage of the newly charged Tello battery. It is usually about 4.35 volts.
Guorium
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Can confirm the battery voltage in flight log shows about 4300mV+ on takeoff.
Update: I was wrong, the log showed below 4300mV on start. I donno what is going on
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As soon as the charge is finished, it reads 4.35 volts, but if we leave them at rest the voltage drops a little ...
Ricardo Penders
Active member
Hello everyone,
I'm currently busy with a Battery mod project for Tello which I'm sharing here on this forum so check out my thread to see exactly what I'm doing and everything that I found out about the battery and the BMS board and the pinout, which pin does what.
Last thing you might want to know is that I'm in direct contact with a manufacturer that makes a cell for about €1.20 - €1.30 per cell and I'm at the moment trying to get those manufactured with a bit more battery capacity if that's possible.
Hope this is helpful to you.
I'm currently busy with a Battery mod project for Tello which I'm sharing here on this forum so check out my thread to see exactly what I'm doing and everything that I found out about the battery and the BMS board and the pinout, which pin does what.
Last thing you might want to know is that I'm in direct contact with a manufacturer that makes a cell for about €1.20 - €1.30 per cell and I'm at the moment trying to get those manufactured with a bit more battery capacity if that's possible.
Hope this is helpful to you.
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