I have found an upcoming 4.4v plus per cell nominal LiPo source, likely going to snowball, after all, who does not want a bit more?:-

https://www.grepow.com/blog/increase-fli...repow.html

So, what have I uncovered during faulting a 1S charger that is overcharging 4.35v LiPo and so supplying HV capable equipment with 4.4 up to 4.47v?

1. Most existing HV capable equipment and models are set up for 4.35v.

2. I have now tested and quickly found TWO mainstream models with commonly used AIO hardware that are HV 4.35v compliant, but that will NOT operate on 4.4v, as it forces their ESCs into failure, their AIO's jagging/stuttering all four props, an imminent failure (or worse) beckoning to those not quick to react!

Probably its worse that some models accept that voltage without visible symptoms, as its unknown if and by how much over safe limits they really are!

3. There's no inherent SAFE way AFAICT to tell a 4.4v (plus) compliant existing hardware item from a non-compliant likely to be damaged item. Certainly not by the current specs/adverts stating HV capable.

Quite concerning, as:-

1. People who just trust their equipment to function as expected without check (not me!) will likely be charging cells limited to 4.35 to plus 4.4, possibly approaching 5v.

2. People who charge to 4.4 approaching 5v and then use these cells will be risking damage, possibly fire, to their existing unsuitable (but notionally HV compliant) hardware.

Seems to me there should be a connector chosen for 4.4v plus use to be different and unique, not allowing connection to older equipment unless people choose to be silly and change it.  

Be VERY careful, it seems its going to get "interesting" !!! ???

It would be great if some standards could be agreed upon for this, but that seems to me like a ship that has sailed long ago. Now we have manufacturers experimenting with marketing voltage binned cells. We had lipo 4.2, then hv at 4.35, now what, hv2 at 4.4, then hv18 at 4.85? These aren't agreed upon standards, and history has taught us all about how that plays out in reality. I don't even want to think about the mix of chargers, devices, and packs the cutting edge crowd will have to deal with in keeping up with all this.

I won't buy these anyways if they won't make a big diff in flight time or performance. Right now I find 4.35 is only really relevant for 1s300 tinywhoops, because they see appreciable gains in flight time vs 4.2. I haven't seen any added value using HV for larger stuff; upping kV or props is always all I've ever needed to stay happy flying cheap 4.2 packs.

(02-Aug-2023, 05:27 PM)BadRaven Wrote: I have found an upcoming  4.4v plus per cell nominal LiPo source, likely going to snowball, after all, who does not want a bit more?:-

https://www.grepow.com/blog/increase-fli...repow.html

So, what have I uncovered during faulting a 1S charger that is overcharging 4.35v LiPo and so supplying HV capable equipment with 4.4 up to 4.47v?                          
                                             

1. Most existing HV capable equipment and models are set up for 4.35v.
     
        Maybe my chargers are just , but...the assorted HV (4.35v) batteries don't always charge
        to 4.35v per cell. Often a battery will register as full and the charging stops at a lower voltage,
        yet...higher than 4.20 v per cell. 
        
2. I have now tested and quickly found TWO mainstream models with commonly used AIO hardware that are HV 4.35v compliant, but that will NOT operate on 4.4v, as it forces their ESCs into failure, their AIO's jagging/stuttering all four props, an imminent failure (or worse) beckoning to those not quick to react!

          Now, I am curious about what gear you are using the UHV (4.4v) batteries in?

          Question here is what are the components rated for and what voltage (or cell count) batteries?
          Most of my gear, especially FC/ESC, are rated for input voltage between 2S-4S with some up
          to 6S. That would be voltages from 6v (the low side of 2S) to 17.4v for 4S and 26.1v (the high
          side of 6S).
          
          Now, I mostly run 3S, high mAh, batteries since I am an endurance pilot rather than a stunt
          pilot. That puts my "high side" voltage at 13.05v for a 4.35v HV battery. It would be 13.4v for
          a 4.4v UHV battery which is still well within the acceptable operating voltage for all components
          including the ESCs.

          In my brain, logic suggests that any voltage less than the maximum rated input for the
          component should be safe. I would never power anything with a battery that has a higher
          voltage than that of the lowest rated component. Yeah, that would just be asking for
          trouble. 
        
  
Probably its worse that some models accept that voltage without visible symptoms, as its unknown if and by how much over safe limits they really are!

3. There's no inherent SAFE way AFAICT to tell a 4.4v (plus) compliant existing hardware item from a non-compliant likely to be damaged item. Certainly not by the current specs/adverts stating HV capable.

        Unless otherwise specified, I consider 1S craft to have a maximum rating of 4.20 volts.
        Even though it seems that most will run with an HV battery charged to not more than
        4.35 volts, I consider this to be marginal and basically the top of the margin. 

        From my experience, most gear will run with HV batteries without incurring damage.
        OK, most of my chargers actually don't seem to charge right up to 4.35 volts per cell.
        That said, I still consider the HV batteries to be at the top of the margin unless the
        manufacturer has specifically rated the components for the higher rating.

Quite concerning, as:-

1. People who just trust their equipment to function as expected without check (not me!) will likely be charging cells limited to 4.35 to plus 4.4, possibly approaching 5v.

         Totally agree. First, do NOT overcharge a battery. As for the gear, I do not use batteries
         with a voltage higher than the rating of the lowest component. In fact, I like having a
         bit of margin.

        How do you charge something to 4.4v when the charger seems to limit the charging
        to 4.35v (or almost)? In my opinion, charging any battery to 4.4 volts per cell or higher
        is not feasible until chargers are manufactured to provide that level of charging.

2. People who charge to 4.4 approaching 5v and then use these cells will be risking damage, possibly fire, to their existing unsuitable (but notionally HV compliant) hardware.

        Totally agree. Simple rule, don't use a power source with a voltage higher than
        the lowest rated component. 

Seems to me there should be a connector chosen for 4.4v plus use to be different and unique, not allowing connection to older equipment unless people choose to be silly and change it.  

        Yet...there is no connector difference between 4.2v per cell batteries and
              4.35v per cell, HV, batteries. Plus, what about the quad? A different
              connector specific to slight voltage differences and not being able to
              use a lower voltage battery? Hmmm.   Think about this 

              I have put an XT30 connector on my last 1S build. Hmmm. So, how
              would that work?  In my mind, the connector should not be a factor
              in the maximum per cell charging limit. 

Be VERY careful, it seems its going to get "interesting" !!! ???

          >> NOTE: I use red as it is high contrast to black. Only to differentiate my comments <<


Hi BadRaven,

My first question is where do you get a charger that will charge to 4.4v per cell and limit it to that?
Do you have to "jerry rig" an existing charger? Until chargers are available with a 4.4 or 4.5 volts
per cell option, then it is a moot point for me. 

My chargers are either specific to a voltage (4.20v or 4.35v per cell) or user selectable between 
4.20v and 4.35v per cell. For me, the charger would need to be able to charge to the higher
voltages whether specifically or selectable in order to charge batteries to that level. 

Unless a battery is specifically listed for 4.4v or higher per cell, then I would never charge it to 
that voltage. My batteries get charged according to the markings on the battery. Even though some 
say that you can charge a 4.20v per cell battery to 4.35v per cell, I don't do that. I charge to what 
the battery is marked.

Now the question is would I buy a 4.4v or 4.5v per cell battery?

Not without an appropriate charger that has that charging option. 
I will not be modifying any battery charger; just NOT going to happen. 

Not for a 1S craft unless the manufacturer specifically rates the craft for the higher voltage. 

Why not? Well, first I would expect a 1S craft to have a maximum voltage rating of 4.20v and 
certainly not over 4.35v. Plus, 1S craft don't fly that long anyway unless you are running a Li-Ion 
cell. For me, trying to squeeze an extra few seconds from a tiny 1S rig is simply not worth it. 
If I want more than 5-7 minutes from a 1S, I will use the highest mAh battery that I can find 
which is probably a Li-Ion cell. Fly time is better extended by using higher mAh cells rather than 
higher voltage. Safer, too. 

I might consider it for 2S+ quads if an appropriate charger is available.

However, I would not push the maximum voltage for any component. That is, if the component 
with the lowest rating was 4S, then I would not use a 4S Ultra High Voltage Battery. However, 
I might use a 3S (4.4v or 4.5v) battery since that would still keep the voltage within the acceptable 
voltage range. 

As always, these are just my thoughts and opinions.  
Yet...they do work well for me. 

Later, iFly  

Not sure how you assumed I'd hacked/modified a charger, I was talking about a commercial 4.35v 1S HV charger that was dangerously (IMO) faulty from new supply and ACTUALLY charging HV 4.35 rated cells to between 4.45 and 4.47. 

Neither am I talking about charging std 4.20v rated cells to HV levels.

MY tests were carried out with Flywoo HV cells and GNB HV cells, both makes listed for 4.35 MAXIMUM voltage cells, that in reality were being overcharged by 0.1-0.12v on a charger sold by a mainstream manufacturer and stated as "very safe" for 4.35v HV.

More testing has revealed that one of the 6 way outputs is cutting off higher than the rest, but they all overcharge on the supplied HV 4.35 setting. 

NO other 1S HV charger I have (and I have a few!) overcharges HV cells beyond 4.35v....... at all......... not even the USB dongle type so beloved of and included with cheap budget chinese quad sellers.

The charger is (oddly) DESIGNED with shorting pads which when solder bridged are supposed to lower the charge cut off voltage to std 4.20. I have now done this and five charge to 4.20-4.23, and the "high" one charges to 4.27 (on average)

I have been promised a replacement, so now we wait.

Hi BadRaven,

Sorry. I misunderstood and didn't realize that the charger was bad from the factory.
I will scratch that.

To clarify, I didn't say the you suggested over charging batteries, I said "some say" that
a 4.20v LiPo can be charged to 4.35v...and they do; I have seen this more than once,
however, we both know that it is Not recommended.

You are also correct that many of the battery chargers out there are a bit unreliable.

Yes, I believe you to be correct. My comments were merely meant as an adjunct to
yours and express my opinions in the various sections. How I power my quads, and
my thoughts about quad batteries over 4.35 volts. Mostly, food for thought. 

Would I intentionally buy those "over voltage" batteries? Probably not. To me it seems
like trying to squeeze out the very last drop of voltage.

Anyway, Happy Flying. 

Later, iFly 

Gotta say, some situations would greatly benefit from a higher voltage range. The first one that came to mind was the 1S Walksnail board that will start to fuzz out around the bottom end of a battery, even if there's still enough to keep going. That said, I'd really prefer it if batteries just had a flatter voltage curve. Not that I can complain too much as I don't have the know-how to design a new type of battery cell.

From my experience, the 1S craft suffer the most with voltage. Consider that a Li-Po can
be drained down to 3.0 volts (sometimes less) although at 3.5 volts a lot of quads just
won't fly. Also consider that the AIO FC might be constructed to handle low voltages,
but a lot of external components require at least 5 volts to operate properly. In the past,
I have used a 5V step up BEC in 1S rigs to power a combo cam/VTX setup. This helps,
but a 1S battery still only has so much juice.  

For me, a 1S tiny whoop is ok indoors even if it is only in the air a few minutes, however,
the quads that I fly outdoors are 2S and up. The extra voltage helps; when a 2S is drained
down (even to 3.0 volts per cell), the voltage is still above 5v so everything still works when
the quad will no longer fly. 

My Tiny-Black-85 is an 85mm framed tiny whoop with 2-inch props and can be powered
by 2S and 3S batteries. It might fly on 1S, but I have not yet tried it. This whoop flies quite
well both outdoors and indoors. For a whoop it is a bit heavy so probably wouldn't be a 
very good ACRO stunt craft, but it works great for how I fly. 

Hi , i was researching about overchargin lipo to 4.5V and your post came up, the brushed whoop jumper x68t has a charger and a 1s lipo inside the box which it charges at 4,5V and than the led turns off, this is the second time i purchase this model the first one consumed its motors before the battery started getting puffy , it works but the battery dont last that much? i was curious cause all of the scare talk about charging 10mv higher and here i am overcharging at 4,5 with a factory charger from jumper fpv, they think its safe , its a tiny racer, longevity of the cell don't mater in race, i still got the first cell , its dead from to much use no fires , in fact i never had a lipo smoke or anything i have overcharged and discharged batteries 3s 1,3mah to 22v-0 by accident they just get warm super puffy and die with no smoke , the pile of dead lipos from all the years are just puffy, In my experience all the scare talk is parroted misinformation, lipo's are safe, i never drilled one.

(18-Feb-2024, 03:34 AM)tsiouflyer Wrote: Hi , i was researching about overchargin lipo to 4.5V and your post came up, the brushed whoop jumper x68t has a charger and a 1s lipo inside the box which it charges at 4,5V and than the led turns off, this is the second time i purchase this model the first one consumed its motors before the battery started getting puffy , it works but the battery dont last that much? i was curious cause all of the scare talk about charging 10mv higher and here i am overcharging at 4,5 with a factory charger from jumper fpv, they think its safe , its a tiny racer, longevity of the cell don't mater in race, i still got the first cell , its dead from to much use no fires , in fact i never had a lipo smoke or anything i have overcharged and discharged batteries  3s 1,3mah to 22v-0 by accident they just get warm super puffy and die with no smoke , the pile of dead lipos from all the years are just puffy, In my experience all the scare talk is parroted misinformation, lipo's are safe, i never drilled one.

one persons experience is not enough to overrule industry wide information. you've been lucky to not experience any fires from lipos. there are posts all over with people who's lipos catch fire during flight(more often crashes) and during charging. Lipo's are safe(r) if treated properly, but there is always a chance a fire could occur. Cell phones with li-ion batteries have caught fire, and lipos are far more reactive.


also 10mv is .01v. youre talking about overcharing by 100mv+. someone who knows how safe lipos are better than the parrots could easily make such a mistake though...

(18-Feb-2024, 03:43 AM)matt0725 Wrote: one persons experience is not enough to overrule industry wide information. you've been lucky to not experience any fires from lipos. there are posts all over with people who's lipos catch fire during flight(more often crashes) and during charging. Lipo's are safe(r) if treated properly, but there is always a chance a fire could occur. Cell phones with li-ion batteries have caught fire, and lipos are far more reactive.


also 10mv is .01v. youre talking about overcharing by 100mv+. someone who knows how safe lipos are better than the parrots could easily make such a mistake though...

Hi , i know my experience as i explained, might be just the  the cells i buy, yes people are debating at posts about 10 or 20mv above if its gonna catch on fire or not.

(18-Feb-2024, 03:34 AM)tsiouflyer Wrote: Hi , i was researching about overchargin lipo to 4.5V and your post came up, the brushed whoop jumper x68t has a charger and a 1s lipo inside the box which it charges at 4,5V and than the led turns off, this is the second time i purchase this model the first one consumed its motors before the battery started getting puffy , it works but the battery dont last that much? i was curious cause all of the scare talk about charging 10mv higher and here i am overcharging at 4,5 with a factory charger from jumper fpv, they think its safe , its a tiny racer, longevity of the cell don't mater in race, i still got the first cell , its dead from to much use no fires , in fact i never had a lipo smoke or anything i have overcharged and discharged batteries  3s 1,3mah to 22v-0 by accident they just get warm super puffy and die with no smoke , the pile of dead lipos from all the years are just puffy, In my experience all the scare talk is parroted misinformation, lipo's are safe, i never drilled one.

Lets lay your "parroted misinformation" statement to rest.

I do not have a large number of people in my flying group. Its a small club, 65ish, but likely only around 25 active, and over half of those fly i.c. power only.  Yet two of my circle..............

1. An electrical engineer had a 2200mAh 3S catch fire in his attached garage late one evening.  It had completed charge a couple of hours back ready for the next day and was not connected to anything.  It took the garage, and the sparks from its roof fire got up into the house roof eaves. By the time the fire service arrived the main roof and upper story were alight. The fire service water extinguishing that ruined the ground floor. He was out of his property for six months plus while it was partially rebuilt. It had no roof left, no ceilings, all contents were lost/ruined and all the plaster had spalled off the walls for a start. It still smells now, many years later.

2. A retired aerospace engineer heard noises in his model room at night, woke him up. He went to investigate and his wife followed him. She touched a flight case standing on the floor with her leg and jumped as it was hot. The metal flight case, insulated with foam sheet, contained three 4000-5000 mAh 6S, and one had started thermal runaway. Again, it was not connected to anything and in this case had been at storage voltage.

These are DIRECT from affected people in my small group, not heresay or unwarrented scare talk.

I'm ignoring other known direct from reliable "horses mouth" or directly observed instances where user action directly contributed to the incident, handling/charging errors. The "funniest" one was one guy who pulled the battery connector apart, byt holding the battery and tugging. The connector came off the battery lead and he was left holding a large battery with fireworks from the shorted leads, like a LoonyTunes cartoon!

Myself?  I have had a couple of large 6S try to run away during 1C charging, caught as I monitor all charging and heard the pack start to expand, promptly feeling its temperature. NO prior symptoms, IR was OK before charge. Not been abused.

Most recently as thread start I bought a 6 way Flywoo 1S charger.  Standard was OK, 4.20v on the nose (which the user had to solder a pair of pads to gain), but HV, its default, was charging to getting close to 4.5v.  Caught initially as a couple of cells got too warm during charge, I was too trusting that the charger was fit for purpose.

SO, your published experience and "nothing to see here, carry on" usage advice is frankly unhelpful. You suggest your charger charges to over voltage but it must be OK as they sell it like it.  That's assuming FAR too much on the quality in design and construct of a lot of model gear sold!


LiPo are useful, currently irreplaceable, essential to our sport, but need careful use, handling, and above all care in control over charging and then storage in a safe manner and place.

I agree with NOT overcharging batteries, any batteries. If I had a charger that
overcharged my batteries, well, I would use something different or use a voltage
limiting device between the battery and the charger.

Do NOT overcharge batteries.

(18-Feb-2024, 09:01 AM)BadRaven Wrote: LiPo are useful, currently irreplaceable, essential to our sport, but need careful use, handling, and above all care in control over charging and then storage in a safe manner and place.

This story sure puts things into perspective. So essentially lipos have to be stored in a fire safe container at all times when unattended. I store my lipos in a lockable ammo container.

What about Li-ion? We have them in power tools, in every smartphone etc and they don't spontaneously combust (too often).

Were do people store Li-ion batteries?

Interestingly, I don't store other types of Lithium batteries anywhere special, 
the back of truck, in the garage, just where ever I am using them. I don't have 
a particular location for Li-Ion batteries. Even though the chemistry is basically 
the same, the Li-Ion batteries don't seem to be a fragile as Li-Po batteries, 
maybe it has something to do with the polymer used.

That said, Li-Ion batteries have and do sometimes explode and cause fires 
in things like EV cars, laptop computers, and other things. While it is a concern, 
you don't see' folks doing anything special with them. What? You gonna put your 
laptop in a "safe" container every time you shut the thing down. Get Real.

So, why is it that Li-Po batteries require extra special care and other packaging 
of Lithium Ion batteries do not? The only thing that I can reasonably think of is 
the particular polymer used in the construction of Lithium Ion Polymer batteries. 

Well, there is one more thing and that is our usage in an aircraft that subjects
the battery to "stress" and even damage:  physical damage due to crashes even
though it might not be seen externally and stress from hard use might also 
factor into it. Now these are just possible considerations as I have no empirical
evidence to prove it. 

Yes, there are horror stories about Li-Po batter explosions, so I do exercise a bit
more caution with them at least when storing and charging. Otherwise, I am the
worst at good battery management. 

Anway, just my 2 cents worth.

more voltage range for the same capacity is a downside about handling and tuning.
i would like a cell which provides capacitiy between lower voltage range, that would give us benefits. better quality cells is what i aim.
hv is just 0.15v tuning on 1s for maybe 5second of the whole flight, elswhere is no benefit when it comes to hv cells in my eyes. i am waiting for better and smaller batteries on 1s, hopfully hv trend on 1 does stop when better quality will come.

betaflight will be in trouble reading 3different voltage and translate in to cellvoltage xD it would result in wrong voltage readout per cell, lots of possible trouble.