Mini 3 pro

[dirkclod]

Can a bigger battery be charged buy a regular Mini 3 charger or do you have to have
A differant charger / yes -no

 

[old man mavic]

@dirkclod yes it just takes longer thats all ,you can charge standard batteries and + batteries mixed in the hub

 

[dirkclod]

@dirkclod yes it just takes longer thats all ,you can charge standard batteries and + batteries mixed in the hub

Thank you

 

[a2tomm]

Can a bigger battery be charged buy a regular Mini 3 charger or do you have to have
A differant charger / yes -no

same charger

 

[Macinfo]

Can a bigger battery be charged buy a regular Mini 3 charger or do you have to have
A different charger / yes -no

Charging has come up a couple times, and you could charge your battery with an old 5W iPhone charger, though it would probably take a day or more to do it..

DJI offers a 30w charger for the Mini 3 separately. But i just got one at local store. USB-C charger, 60w. it charges my devices relatively quick, just be aware that despite it being a 60W charger, the device being charged will only take the amount of current it needs...

There are a number of YT videos showing people charging various devices with a USB Power Meter inline, and whatever they are charging never exceeds what the device needs no matter how large the charger in watts.. if your using a smaller charger then a device wants, it merely takes longer to charge it. And then videos show that smaller chargers are only delivering what the charger is rated for until the size of the charger exceeds what the device wants then it stops and stays at the device limit, while you wait for charging to complete.

 

[jphoto]

Charging has come up a couple times, and you could charge your battery with an old 5W iPhone charger, though it would probably take a day or more to do it..

DJI offers a 30w charger for the Mini 3 separately. But i just got one at local store. USB-C charger, 60w. it charges my devices relatively quick, just be aware that despite it being a 60W charger, the device being charged will only take the amount of current it needs...

There are a number of YT videos showing people charging various devices with a USB Power Meter inline, and whatever they are charging never exceeds what the device needs no matter how large the charger in watts.. if your using a smaller charger then a device wants, it merely takes longer to charge it. And then videos show that smaller chargers are only delivering what the charger is rated for until the size of the charger exceeds what the device wants then it stops and stays at the device limit, while you wait for charging to complete.

It's just a little matter of fire prevention. If they didn't current-limit batteries and chargers, the could ignite. A few Li-ion batteries do anyway.

 

[Macinfo]

It's just a little matter of fire prevention. If they didn't current-limit batteries and chargers, the could ignite. A few Li-ion batteries do anyway.

Still need to take care of course. Have not seen as many battery fire or poof stories recently, but some probably still occur. I usually do not leaving charging batteries un-attended. and disconnect them when I note they are charged.

 

[jphoto]

Still need to take care of course. Have not seen as many battery fire or poof stories recently, but some probably still occur. I usually do not leaving charging batteries un-attended. and disconnect them when I note they are charged.

There seems to be a bigger issue with larger batteries like those in e-bikes. Saw a recent story that there have been 100+ battery explosion fires in NYC that resulted in injury or property loss. Other than using similar chemistry they are nothing like a drone battery in capacity, size, current, etc. But they burn down homes, so they make the news. I doubt they are as “smart” as a DJI drone battery. But I’m burning petrol in my scooter for the foreseeable future.

 

[Macinfo]

There seems to be a bigger issue with larger batteries like those in e-bikes. Saw a recent story that there have been 100+ battery explosion fires in NYC that resulted in injury or property loss. Other than using similar chemistry they are nothing like a drone battery in capacity, size, current, etc. But they burn down homes, so they make the news. I doubt they are as “smart” as a DJI drone battery. But I’m burning petrol in my scooter for the foreseeable future.

E-bike batteries probably take more abuse too, people dropping the bike could generate impacts, depending on how well its protected.

Yeah, going all EV I don't think its all that great of an idea, the batteries are not always stable, and not sure they can make them super stable, but that's a topic for an entirely different discussion....

 

[Droning on and on...]

It's just a little matter of fire prevention. If they didn't current-limit batteries and chargers, the could ignite. A few Li-ion batteries do anyway.

This is not accurate.

All batteries have an "internal" resistance, and this is what limits current draw during charging at a fixed voltage. Charging at the maximum (i.e. a 4.2V supply with sufficient power to deliver the current draw at the battery's resistance, V=IR applies) it'll probably get hot, but is very unlikely to explode or catch fire.

What causes lithium chemistry batteries to fail catastrophically is overcharging, which results in the production of hydrogen gas in the pack. Eventually the pressure causes rupture, the battery shorts, and the full energy of the battery is released quite spectacularly.

Overcharging is the result of an overvoltage at the terminals – >4.2V (4.35 for HE cells). During charging, current is controlled by adjusting the voltage presented to the battery. The charging process is a bit more complicated, first delivering Constant Current with the voltage slowly climbing to 4.2, then switching to a fixed voltage while the charge current gradually declines.

Current is limited generally to 1C (1x the rated capacity in mAh, in Amps – i.e. a 3000 mAh cell optimally charges at 3000mA rate, charging in about an hour). This is to preserve capacity, mainly, and cycle life. There are rapid-charge applications that used exactly the same cells but charge at 3-5C, sacrificing pack life in favor of expediency. These packs are simply replaced (a lot) more often. EMS applications are an example.

While the cell can probably charge much faster, the reason the BMS limits charging current primarily preserves capacity, not for fire prevention.

 

[jphoto]

The current crop of e-bike Li-ion battery fire reports contain many instances of charging OEM batteries with OEM chargers with the proper charge management. The cause is not necessarily over-charging, but battery failure, damage, or abuse.

Here's one reference (yeah, they are selling a product):

E-bike battery fires : How safe are you ?- LithiumSafe

There is a growing number of E-bike battery fires. Lithium batteries can catch fire unexpectedly. A serious risk for consumers and shop owners.

www.lithiumsafe.com

This one lists causes for Li-ion fires, and does include "using the wrong charger", which may imply and over-charge situation, but it's only one of several causes:

Causes of E-Bike Fires and What to Do When They Happen | JD Supra

A recent surge of electric bike fires in NYC has brought new attention to the dangers of lithium battery fires and increased scrutiny of safety...

www.jdsupra.com

This reference lists thermal runaway as the cause, result of defects, damage, excessive temperature, and over-charge.

E-bike battery fires and how to stop them - Features - BikeBiz

A rise in fires involving e-bike batteries recently prompted the London Fire Brigade to issue a warning, urging people to only use trusted batteries and be careful to charge and store them correctly. asecos’ Les Day explains the risks and how storage cabinets can protect against fires and...

bikebiz.com

 

[jphoto]

This is not accurate.

All batteries have an "internal" resistance, and this is what limits current draw during charging at a fixed voltage. Charging at the maximum (i.e. a 4.2V supply with sufficient power to deliver the current draw at the battery's resistance, V=IR applies) it'll probably get hot, but is very unlikely to explode or catch fire.

All true assuming a good battery with reasonable ambient temperature and no defects or damage.

What causes lithium chemistry batteries to fail catastrophically is overcharging, which results in the production of hydrogen gas in the pack. Eventually the pressure causes rupture, the battery shorts, and the full energy of the battery is released quite spectacularly.

Overcharging is the result of an overvoltage at the terminals – >4.2V (4.35 for HE cells). During charging, current is controlled by adjusting the voltage presented to the battery. The charging process is a bit more complicated, first delivering Constant Current with the voltage slowly climbing to 4.2, then switching to a fixed voltage while the charge current gradually declines.

Current is limited generally to 1C (1x the rated capacity in mAh, in Amps – i.e. a 3000 mAh cell optimally charges at 3000mA rate, charging in about an hour). This is to preserve capacity, mainly, and cycle life. There are rapid-charge applications that used exactly the same cells but charge at 3-5C, sacrificing pack life in favor of expediency. These packs are simply replaced (a lot) more often. EMS applications are an example.

While the cell can probably charge much faster, the reason the BMS limits charging current primarily preserves capacity, not for fire prevention.

That's an excellent description of proper charging and over-charging. What's missing is what goes wrong and causes them to explode. Over-charging is one possibility, but given that battery charge management has been a well known fact of life for the last 40 years or so, it would be kind of a surprise unless someone uses the wrong charger, which is also possible.

My other post lists more likely causes.

At least some of the investigations into battery fires have shown it was an OEM battery and charger, which doesn't mean over-charging was impossible, just fairly unlikely.

 

[Droning on and on...]

The current crop of e-bike Li-ion battery fire reports contain many instances of charging OEM batteries with OEM chargers with the proper charge management. The cause is not necessarily over-charging, but battery failure, damage, or abuse.

Yup. There are plenty of reports of DJI batteries too, swelling, some even more catastrophic failures, all while charging on well-engineered power supplies working properly as designed.

Batteries, like all manufactured items, have an inherent defect rate.

What does this have to do with overcurrent during charging good batteries, which is what you asserted risks causing li-ion chemistry batteries to spontaneously burst into flames?

That's what I was responding to.

 

[jphoto]

Yup. There are plenty of reports of DJI batteries too, swelling, some even more catastrophic failures, all while charging on well-engineered power supplies working properly as designed.

Batteries, like all manufactured items, have an inherent defect rate.

What does this have to do with overcurrent during charging good batteries, which is what you asserted risks causing li-ion chemistry batteries to spontaneously burst into flames?

That's what I was responding to.

I said, " If they didn't current-limit batteries and chargers, the could ignite. A few Li-ion batteries do anyway."

There's nothing inaccurate there. The confusion probably came from the above being a very general statement, and of course they do current limit in several ways, so not typically applicable. But, I didn't assert that the lack of current limiting was THE cause of li-on batteries exploding in flames.

Otherwise, the links sited include many more realistic cases.

We both seem to tend toward the pedantic in our quest for accuracy. Nothing wrong with the quest, but I'll try to current-limit my pedanticism so it doesn't cause the thread to explode in flames.

 

[Droning on and on...]

I said, " If they didn't current-limit batteries and chargers, the could ignite. A few Li-ion batteries do anyway."

There's nothing inaccurate there.

Well indeed there is. We've come full circle. I already responded to what you repeated, in post #10, explaining why there is a current limited, Constant Current phase of charging.

I am very clear that you don't accept this. Let's move on.

 

[jphoto]

Well indeed there is. We've come full circle.

"Well indeed there is" is hardly an invitation to "move on", now is it?

We're attempting to have a technical duscussion, so objectivity should be present. Which means, when a statement is made, it should be able to be backed up with reference (otherwise it's a opinion, which is subjective). If an inaccurate or incorrect statement is made, it's more helpful to cite a reference than just claim a statement is and say "lets move on".

Lets define over-charging:
"Overcharging occurs when a battery is charged to a higher than specified voltage."

And how do you get the terminal voltage higher? You first have to eliminate current limiting, with the result being a higher voltage. ANY proper current limiting will prevent over-voltage. Without current limiting the terminal voltage, after charging to the correct level, will continue to go up. If you simply regulate the terminal voltage to the maximum permissible, you have, in essence, provided a type of current limiting, though excessive cell heating will likely still result.

Now lets define the cause of li-ion explosions:

"Why Li-ion Batteries Explode" (important reference from this link is below)

"Normally, it’s a manufacturing defect, and apparently that was the situation with the Note7 phones. But the underlying issue is that Li-ion batteries contain a lot of energy in a compact package—which, of course, is why they are used in everything from phones to Tesla electric cars.

A Li-ion battery has an energy density of up to around 160 watt hours per kilogram (Wh/kg), roughly twice that of a fresh alkaline battery or a NiCad rechargeable battery. To produce that power it relies on three main components: the positively charged cathode, which is made of metal oxide, the negatively charged anode, which is made of graphite, and the liquid electrolyte—a solvent containing lithium salts—that enables the electric charge to flow between the two poles.

Like two troublemakers in a grammar school classroom, the cathode and the anode need to be physically separated. Lithium-ion batteries accomplish that with a permeable polyethylene separator, which can be as little as 10 microns thick. As batteries improve and engineers try to pack more power into a smaller package, that thin plastic separator is taxed to its limit.

“The separator has really gotten thin,” says Isidor Buchmann, founder and CEO of Cadex, a battery equipment manufacturer that also runs the educational website Battery University. “And when that happens, the battery becomes more delicate.”

When the separator is breached, it causes a short circuit, which starts a process called thermal runaway. According to Abraham, this is one of the major ways that fires begin. The chemicals inside the battery begin to heat up, which causes further degradation of the separator. The battery can eventually hit temperatures of more than 1,000° F. At that point the flammable electrolyte can ignite or even explode when exposed to the oxygen in the air.
Will these catastrophic failures, rare though they may be, spell the end of the Li-ion battery? Not likely, says Buchmann. While safety is a concern, it’s just one of a number of factors in battery design. Most of the others are related to energy density, battery life and charging performance."

Notice that overcharging is not mentioned specifically, and that's correct, it's not the usual cause, but it is a cause. Here's the reference for that:

"In a lithium-ion battery, overcharging can create unstable conditions inside the battery, increase pressure, and cause thermal runaway. "
(from Is it Ok to Leave a Lithium-Ion Battery on the Charger? And Other Forklift Battery Charging FAQs)

I already responded to what you repeated, in post #10, explaining why there is a current limited, Constant Current phase of charging.

As to post #10, there are plenty of inaccuracies there to deal with.

"Charging at the maximum (i.e. a 4.2V supply with sufficient power to deliver the current draw at the battery's resistance, V=IR applies) it'll probably get hot, but is very unlikely to explode or catch fire."

If you regulate the charging voltage to the correct maximum terminal voltage you have just applied a current limit as well. And "unlikely" also means "could".

"What causes lithium chemistry batteries to fail catastrophically is overcharging, which results in the production of hydrogen gas in the pack. Eventually the pressure causes rupture, the battery shorts, and the full energy of the battery is released quite spectacularly."
Overcharging is only one cause, and not the most common. In fact, overcharging is one method that can induce thermal runaway. I've already posted links that clear up this inaccuracy.

"Current is limited generally to 1C (1x the rated capacity in mAh, in Amps – i.e. a 3000 mAh cell optimally charges at 3000mA rate, charging in about an hour). This is to preserve capacity, mainly, and cycle life. There are rapid-charge applications that used exactly the same cells but charge at 3-5C, sacrificing pack life in favor of expediency. These packs are simply replaced (a lot) more often. EMS applications are an example. While the cell can probably charge much faster, the reason the BMS limits charging current primarily preserves capacity, not for fire prevention."

We go back to "Why do li-ion batteries explode/catch fire.

Here's a reference that deals with the real cause of li-ion fire:
"Why do Lithium Batteries Catch Fire?
Most fires that occur from lithium batteries are due to thermal runaway. A thermal runaway happens when conditions are met that cause reactions to occur and cannot be easily stopped. These reactions are exothermic, meaning that they give off heat, and that heat may be enough to cause a fire.

We know that physical damage or electrical abuse, such as short circuits, overcharging, and exposure to elevated temperatures, can cause a thermal runaway. Additionally, manufacturer defects, such as imperfections and/or contaminants in the manufacturing process, can also lead to thermal runaway.

Thermal Runaway in Lithium Batteries​

During thermal runaway of battery, a reaction can occur, which vaporizes the organic electrolyte and pressurizes the cell casing. If, or when, the case fails, the flammable and toxic gases within the cell are released. Once a thermal runaway starts, the process cannot be stopped, even by unplugging the battery. Even worse, you may not know when this runaway starts. Therefore, it is best to make sure that the battery is being charged in a safe place where other fuels will not be ignited.

To minimize the possibility of thermal runaway the battery, charger, and device manufacturers use battery management systems to make sure that the batteries are operated within a voltage, current, and temperature range that is considered safe. For example, if a lithium-ion powered device says the battery is dead and the device will not operate, the actual battery is not dead, instead, it has reached the lower level of safe operation and a good management system will not allow the use of the device."

The above reference outlines the real and common failure mechanism of a li-ion battery. The bold sentece above shows that thermal runaway is possible without proper and safe charging.

Lack of current limiting is one potential cause of thermal runaway, because to limit current in a way that controls the cell temperature you must also regulate terminal voltage.

Thermal runaway is the acutal root cause of li-ion fires.

A provable improper charging design that produces excessive heat becomes the cause of thermal runaway, which is the cause of fire. Li-ion battery fires have already caused 66 fires and five deaths in NYC alone as of August 3, 2022. The totals are no doubt much higher for the global scope.
Reference here.

Now, if you're an OEM, and designing any product with a li-ion battery, your legal department will have something to say about your excessive heating charging circuit once they've received the law suit citing liabilitiy for a death. And now, your BMS is all about controlling liability, and preserving battery life becomes secondary.

What's not in the news is fires caused by exploding drone batteries. Or are they? A quick google search turned up this:

Recharging Drone Batteries Burns Fire Department to the Ground​

But, frankly, it is one story. And while not the only drone battery fire on record, drone battery fires are far fewer in number than e-bike battery fires and electric car battery fires currently in the news. But they are still a non-zero risk.

This might be useful to some, re: battery use and care information.

https://psflight.org/10854/recharging-drone-batteries-burn-fire-department-to-the-ground/
https://psflight.org/10854/recharging-drone-batteries-burn-fire-department-to-the-ground/
I am very clear that you don't accept this. Let's move on.

I'm all for moving on, but not at the expense of accurate information so that all here may learn. Myself included.

 

[Droning on and on...]

Cool @jphoto, you're obviously much smarter!

Let's move on.

 

[jphoto]

Cool @jphoto, you're obviously much smarter!

Thanks, but that's not the point (nor true). I just believe that forum readers deserve the most accurate information available, it's not about who is right or wrong or why. We all benefit from the collective knowledge.

Let's move on.

Done. I'm off to shoot some drone camera evaluation tests.