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Don't Buy a Talent Cell or Other Power Bank Until You Read This

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#1 CA Curtis 17

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Posted 29 July 2023 - 11:09 AM

After owning a Talent Cell 8.3Ah power bank since the total solar eclipse of 2017 I was surprised to discover recently that most of these power banks from Talent Cell and other manufacturers advertised as 12V supplies do not actually put out 12V once a load, even a 1 amp load, is applied.  Worse, the voltage drops very quickly and at least 30% of the rated capacity is under 10V.  While much of the astronomy equipment we use is fairly forgiving with respect to 12V, not all is, and even then there is a limit to how low the voltage can go before the equipment no longer functions correctly.  I have seen reports of ZWO's AM5 and their ASIAIR not playing well with power banks.  So I bought 3 different power banks to bench test and then test on a couple of my mounts and with my Beelink mini-pc.  Once I dug into the design used for these power banks it was clear why they are not all true 12V batteries.  I put all of my tests and analyses into a short video which you can find here. https://www.youtube....Zm-tGT40No&t=1s  There is one Talent Cell power bank which truly is a 12V supply which I also show in the video.  If you are thinking of purchasing a power bank from any manufacturer you might want to check this out first.  If you have had trouble with one of your power banks you may find out why in this video.  

 

I would appreciate hearing back from anyone who has had trouble with their power bank and also from those who have never seen a problem with it powering their equipment.  Obviously it works, at least for some part of the rated capacity, for lots of equipment but not all and we are probably not getting the full capacity as advertised since the voltage drops so low so fast.

 

Best Regards,

Curtis


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#2 Oyaji

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Posted 29 July 2023 - 11:50 AM

This is one reason to use LiFePO4 batteries.  When charged they are about 13.6 volts but fairly quickly drop back to 13.4V.  And a 20aH LiFePo4 battery will easily last all night, never dropping below 12V.  And it is very light.  

 

I have never fried any piece of gear--mounts, cameras, focusers--using a LiFePO4 battery.  

 

State of Charge chart:  https://cleversolarp...-voltage-chart/



#3 JohnBear

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Posted 29 July 2023 - 11:55 AM

This is a nice informative  "short" (21 minute) video about 12V power banks..  Good presentation!

 

A suggestion;  Since you are testing and comparing four individual "12V" power banks, I would recommend use this video to edit/create 4 additional individual short (5 minutes or less) videos - one for each of 4 power banks - and maybe a short comparison summary video. 

 

My experience is that viewers tend to hesitate to click on videos that are over 5 minutes. So, by creating additional 4-5 short videos from this comprehensive video, you will have more available content on your channel for users to select from. 



#4 CA Curtis 17

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Posted 29 July 2023 - 01:51 PM

This is one reason to use LiFePO4 batteries.  When charged they are about 13.6 volts but fairly quickly drop back to 13.4V.  And a 20aH LiFePo4 battery will easily last all night, never dropping below 12V.  And it is very light.  

 

I have never fried any piece of gear--mounts, cameras, focusers--using a LiFePO4 battery.  

 

State of Charge chart:  https://cleversolarp...-voltage-chart/

This is not the correct take-away.  LiFePO4 batteries are great, but so are LiNiMnCoO2 which are used in Jackery portable power stations and a lot of other power stations.  The voltage on those also never drops below 12V until 100% of the capacity has been drained and the internal BMS shuts it down.  There is no more reason that you would fry something with one of these types of power supplies either.  In fact, they have a voltage regulator so the output is more stable than with a LiFePO4 battery.  But both are great.  The problem with most power banks is that they are not properly designed to provide 12V even for the first 30seconds of load.  Watch the video and you will come away with a better understanding of how both types of lithium chemistries work.

 

Best Regards,

Curtis



#5 Bill Lee

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Posted 30 July 2023 - 08:46 AM

The first thing I noticed about this specific power bank is that the charger only output 12.6V. Since the voltage of even four LiFePO4 cells in series is 12.8 (which only has 3.2V per cell), then this power bank doesn’t have 4 cells. Most likely, it has three cells of 3.6V, for a 10.8V. I’m sure that many things run fine off this voltage that is designed for a 12V lead-acid battery (which bottoms out at 10.8V), but I feel better using 4 cells.

 

My experience is that lithium cobalt oxide has been the earliest, most popular lithium rechargeable batteries and have become synonymous as “lithium ion” batteries. Indeed, I assume, unless otherwise specified, that “lithium ion” means lithium cobalt oxide.

 

However, lithium cobalt oxide has a disturbing penchant to burst into flames when damaged.  I generally build batteries out of LiFePO4 (lithium iron phosphate) chemistry batteries which tend not to burst into flames. These two are, in my experience, the two most widely available lithium for purchase by consumers.

 

In summary:

 

  • Lithium ion (aka lithium cobalt oxide)
    • Pros:
      • Higher energy density
      • Higher voltage of 3.6V per cell
      • Widely available, in consumer sizes A, AA, AAA, C, D sizes, as well as other cylindrical batteries used in cordless tools, rechargeable flashlights, etc; and rectangular (aka “prismatic”) sizes
      • Relatively inexpensive
    • Cons:
      • Prone to bursting into fire
  • ​LiFePO4 (aka lithium iron phosphate)
    • Pro
      • Safer
      • Also widely available
    • Cons
      • Lower energy density
      • More expensive
      • Lower voltage (3.2V)

Edited by Bill Lee, 30 July 2023 - 08:46 AM.

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#6 CA Curtis 17

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Posted 30 July 2023 - 09:21 AM

 

The first thing I noticed about this specific power bank is that the charger only output 12.6V. Since the voltage of even four LiFePO4 cells in series is 12.8 (which only has 3.2V per cell), then this power bank doesn’t have 4 cells. Most likely, it has three cells of 3.6V, for a 10.8V. I’m sure that many things run fine off this voltage that is designed for a 12V lead-acid battery (which bottoms out at 10.8V), but I feel better using 4 cells.

 

 

Seems like you did not watch the video, but you have the right take-away in that most of the power banks scrimp on the number of cells I believe to keep the cost, size and weight down.  That's fine until the decide to advertise it as a 12V battery which it is not.

 

 

My experience is that lithium cobalt oxide has been the earliest, most popular lithium rechargeable batteries and have become synonymous as “lithium ion” batteries. Indeed, I assume, unless otherwise specified, that “lithium ion” means lithium cobalt oxide.

 

LiCoO2 is most commonly used in phones and laptops but you will not find it in large batteries, portable power stations like the Jackerys and those from other manufacturers, nor in any power bank that I am aware of.

 

"Li Ion" means any lithium chemistry that produces electricity by moving Li ions from an anode to a cathode.  While that includes LiCoO2, it also includes LiFePO4, LiNiMnCoO2, and others.  There term "Li ion" is heavily misused, like you are doing here, and results in lots of confusion.  Even many sellers of Li ion products misuse the term.  Let's not continue to confuse people and use it correctly going forward 

 

 

However, lithium cobalt oxide has a disturbing penchant to burst into flames when damaged.  I generally build batteries out of LiFePO4 (lithium iron phosphate) chemistry batteries which tend not to burst into flames. These two are, in my experience, the two most widely available lithium for purchase by consumers.

 

In summary:

 

  • Lithium ion (aka lithium cobalt oxide)
    • Pros:
      • Higher energy density
      • Higher voltage of 3.6V per cell
      • Widely available, in consumer sizes A, AA, AAA, C, D sizes, as well as other cylindrical batteries used in cordless tools, rechargeable flashlights, etc; and rectangular (aka “prismatic”) sizes
      • Relatively inexpensive
    • Cons:
      • Prone to bursting into fire
  • ​LiFePO4 (aka lithium iron phosphate)
    • Pro
      • Safer
      • Also widely available
    • Cons
      • Lower energy density
      • More expensive
      • Lower voltage (3.2V)

 

Indeed, LiCoO2 has a low thermal runaway temperature and can more easily burst into flames than LiFePO4 or LiNiMnCoO2 if abused by over charging or operating at too high of a temperature.  This is the chemistry which we hear most often about causing fires on airplanes.

 

You left out LiNiMnCoO2 which is the chemistry of choice for high energy density and reasonably high thermal runaway temperature, second only to LiFePO4.  It has a cell voltage of 3.6-3.7V and is found in power tools, ebikes, portable power stations and many Tesla designs.

 

Best Regards,

Curtis



#7 Bill Lee

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Posted 30 July 2023 - 12:19 PM

Seems like you did not watch the video, but you have the right take-away in that most of the power banks scrimp on the number of cells I believe to keep the cost, size and weight down.  That's fine until the decide to advertise it as a 12V battery which it is not.

 

No, I didn’t watch the video (there wasn’t one on Amazon smile.gif ). I’m betting that “12V” means “about 12V”. I’m sure we both know how these things go…. Caveat emptor! I tend to now follow Hanlon’s Razor to these sort of things: "Never attribute to malice that which is adequately explained by stupidity." (I came to this mindset after a lifetime of trying to explain technical things to non-technical people.)

 

Sorry I left out LiNiMnCoO2. I stand corrected. 

 

I should have also added a warning that people make sure they are understand watt hours vs. amp hours. I’ve seen vendors use watt hours to make it seem like their power packs contain more energy than those rated in amp hours. People need to know the difference between power and current….

 

Cheers,

Bill


Edited by Bill Lee, 30 July 2023 - 12:20 PM.

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#8 CA Curtis 17

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Posted 21 October 2023 - 10:19 AM

Looks like TalentCell added a second LiFePO4 power bank to their offerings of small portable batteries.  This one is slightly lower capacity but has an LCD digital power display instead of the 4 green lights.  

 

Again, I only recommend the LIFePO4 versions of their small portable batteries as true 12V supplies and not any of the many other ones they call 12V but which are, in my view, more accurately called 11V supplies.  Check the video if you want all the details.


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#9 pk_davidson

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Posted 19 April 2024 - 04:02 PM

Very interesting and useful info. 
I have been using the low end Talentcell on a couple of low draw scopes without issue. 
However, I haven’t run them for more than 4-5 hours max and it was only the motors & controller drawing. 
 

I am working toward a much bigger OTA setup with AP so the 4 cell design makes sense. 
Thank you

 

maybe you could post a summary page here with the links for purchase?

or does that violate clodynights protocols?

 



#10 mich_al

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Posted 19 April 2024 - 07:48 PM

I'll also add that I have used a 12V Talentcell on both my CGEM and Losmandy G11 mounts with good results.  My usage is generally 3-4 hrs and recharge the next day.  Never had a problem in several years of use,


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#11 HeyJP

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Posted 20 April 2024 - 02:07 PM

Great thread! Thanks Curtis for explaining this and especially the subtlety that it’s not the LIFE by itself but LIFE coupled with four cells. I used the older talent cells for many years with my Celestron telescope and iOptron mounts. Could run all night without a problem. But as soon as I picked up my AM5 mount this year, those same bstteries started screaming within minutes. So I picked up one of the LIFE 4-cell talent cells, and it works much better.

 

Thanks!


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#12 ButterFly

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Posted 20 April 2024 - 03:17 PM

Talentcell 12V batteries have a 9V regulated supply port.  The 9V remains constant, whereas the 12V varies between about 12.6 at full and 10.4 at dead.

 

Talentcell 24V batteries have a 12V regulated supply port.  If you need a constant 12V supply, opt for a Talentcell 24V battery with a 12V regulated supply.

 

Note that the regulated supplies on both the 12V and 24V batteries have different connectors than the unregulated higher voltage supply port.  This is to avoid accidents.  The unregulated higher voltage supply is typically 5.5x2.1mm whereas the regulated lower voltage supply is 5.5x2.5mm.  This is so that you can't plug into the 12V by accident if you want 9V.

 

For most of my uses, the unregulated 12V port has been fine.  One 11Ah battery powers my AVX for five or more days, and my ServoCat for about 3-4 days.  When I have a computer connected as well, or when I'm tracking satellites with ServoCat, I want a regulated 12V supply, so I just use a buck-boost converter between the battery and the devices.  A 60W (12V 5A) buck boost converter isn't large, and handles all of my field needs.


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#13 CA Curtis 17

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Posted 21 April 2024 - 09:28 AM

Talentcell 12V batteries have a 9V regulated supply port.  The 9V remains constant, whereas the 12V varies between about 12.6 at full and 10.4 at dead.

 

 

The 12V port only provide 12.6V if there is no load.  Once a load is supplied the voltage drops below 12V immediately.  This is because of they use a 3S design with LiNiMnCoO2 cells instead of a 4S design which would require a voltage regulator for the 12V output.  Of course, their LiFePO4 model does provide 12V + over 95% of its capacity as I have said.  You can see the voltage versus capacity curves for 4 different TalentCell "12V" power banks in video link I provided in post #1.

 

 

 

Talentcell 24V batteries have a 12V regulated supply port.  If you need a constant 12V supply, opt for a Talentcell 24V battery with a 12V regulated supply.

 

It certainly is true that the 24V models do supply a regulated 12V output and these can probably be used as a 12V supply without the problem described with their "12V" models.  They do not indicate the number of cells in series used in their 24V models but from the spec (29.4V - 21V)  I am guessing it uses 7 LiNiMnCoO2 cells in series since 7 x 4.2V = 29.4V.  LiNiMnCoO2 cells have an infinitesimally small capacity at 4.2V so the battery will show 29.4V with no load but then drop down to 7 x 3.6V = 25.2V once a load is applied just like the 3S cell designs show 12.6V with no load.   And the voltage will drop to 7 x 3.0V = 21V when the output is shut down by the internal BMS.  If that is correct, these would also supply 24V with a load, but I am not sure for what percentage of the capacity since there obviously is no regulation at 24V.

 

For most of my uses, the unregulated 12V port has been fine.  One 11Ah battery powers my AVX for five or more days, and my ServoCat for about 3-4 days.  When I have a computer connected as well, or when I'm tracking satellites with ServoCat, I want a regulated 12V supply, so I just use a buck-boost converter between the battery and the devices.  A 60W (12V 5A) buck boost converter isn't large, and handles all of my field needs.

I think I have already mentioned that I have been able to use one of the unregulated 12V Talentcell power banks to run my 6SE and uncooled camera for public outreach events without any problems.  I did not actually know for several years about the internal design limitations.   But, some equipment will not be happy with the low voltage supplied ( 11V and even 10V) for most of the capacity.  My recommendation still remains to get the model labeled as using LiFePO4 because it uses 4 cells in series and, therefore, doesn't need a voltage regulator to provide an output voltage under load of >12V for 95% of its capacity.  



#14 ButterFly

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Posted 21 April 2024 - 02:55 PM

It certainly is true that the 24V models do supply a regulated 12V output and these can probably be used as a 12V supply without the problem described with their "12V" models.

Probably?  It's a 12V regulated supply.




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