[rm105]

It's long been said that most LiPo batterys are over rated, IE they may claim to be a 69Ah 420C monster but in actuality are closer to a 1Ah 15c kitten. I recently realized I have the right tool on hand to actually measure capacity and internal cell resistance in LiPo packs (needed to calculate C & max continuous current draw) which means we can put some real data behind that claim... So, let's do a science :3

Device used for charging, resistance checks, discharging:
Turnigy Accucell C150

Goal:
Document true / real-world performance of various LiPo battery packs commonly used in Airsoft applications
Determine which brands, if any, can be relied on to accurately rate their LiPo packs

Method:
Balance charge new/unused LiPo w/ 1A charging current until steady 4.2v/cell
Allow to stabilize / reach ambient temp for ~1hr (~75f)
Measure Internal cell resistance, note highest individual value of 5 tests
Discharge battery fully w/ 2A max load (regulated by controller) until steady 3.2v/cell
Record total measured capacity

Notes:
In this post I will only included data from brand new / unfielded LiPo batteries
In a later post I will share data for a few batteries which have seen years of real-world use and abuse
I am open to testing more batteries if there's any popular requests
I tried to get the same form-factor packs for testing
Internal cell resistance is measured in milliohms
I did not re-balance cells after stabilization / cool-down period
I do not have a standardized method to measure burst current or C rating (yet)
Most batteries were changed to Deans before test - will do a deans/molex comparison w/ same battery at later date
C Rating and Max Continuous Discharge will be calculated using this web tool
The 'score' is the averaged summed percentage accuracy of capacity and C ratings, higher is better

This is not a conclusive test! Data collected from a single cycle of a single pack, which may be golden or defective, does not condone nor condemn an entire brand - please be mindful when drawing conclusions from such limited data.


Turnigy 1200mAh 15-25c 3s 11.1v (stick) ★
Fully charged: 4.204v 4.204v 4.204v
Internal resistance: 22 25 25 (26 highest)
Fully discharged: 3.247v 3.242v 3.249v
Measured capacity: 1194 mAh
Calculated C Rating: 14.2c
Max Continuous Current: 16.95A
Score: 97

Turnigy 1200mAh 25-50c 2s 7.4v (stick)
Fully charged: 4.204v 4.204v
Internal resistance: 27 26 (29 highest)
Fully discharged: 3.243v 3.237v
Measured capacity: 1168 mAh
Calculated C Rating: 13.6c
Max Continuous Current: 15.88A
Score: 75

echo1 1100mAh 25c 3s 11.1v (stick)
Fully charged: 4.204v 4.204v 4.200v
Internal resistance: 24 20 45 (47 highest) <--- bad IR reading indicates low QC
Fully discharged: 3.376v 3.218v 3.416v
Measured capacity: 834 mAh
Calculated C Rating: 12.6c
Max Continuous Current: 10.50A
Score: 63

echo1 1100mAh 25c 2s 7.4v (stick)
Fully charged: 4.204v 4.202v
Internal resistance: 21 23 (24 highest)
Fully discharged: 3.203v 3.224v
Measured capacity: 1054 mAh
Calculated C Rating: 15.7c
Max Continuous Current: 16.54A
Score: 79

Lancer Tactical 1500 20c 3s 11.1v (brick)
Fully charged: 4.204v 4.204v 4.204v
Internal resistance: 13 15 17 (19 highest)
Fully discharged: 3.257v 3.401v 3.247v
Measured capacity: 1111 mAh
Calculated C Rating: 17.2c
Max Continuous Current: 19.10A ★
Score: 80

Lancer Tactical 1300mAh 25c 2s 7.4v (stick)
Fully charged: 4.195v 4.204v
Internal resistance: 22 25 (27 highest)
Fully discharged: 3.203v 3.224v
Measured capacity: 1197 mAh
Calculated C Rating: 13.9c
Max Continuous Current: 16.63A
Score: 73

Crazepony 2000mAh 30c 3s 11.1v (stick)
Fully charged: 4.202v 4.204v 4.204v
Internal resistance: 14 15 15 (17 highest)
Fully discharged: 3.247v 3.242v 3.249v
Measured capacity: 922mAh
Calculated C Rating: 20c ★
Max Continuous Current: 18.44A
Score: 56

Venom Fly 800mAh 30c 3s 11.1v (brick) ★
Fully charged: 4.204v 4.204v 4.204v
Internal resistance: 14 18 20 (20 highest)
Fully discharged: 3.218v 3.218v 3.226v
Measured capacity: 949mAh
Calculated C Rating: 18.1c
Max Continuous Current: 17.17A
Score: 89

Goldbat 1300mAh 25c 3s 11.1v (stick)
Fully charged: 4.204v 4.204v 4.204v
Internal resistance: 18 16 19 (20 highest)
Fully discharged: 3.213v 3.255v 3.211v
Measured capacity: 1283mAh
Calculated C Rating: 15.6c
Max Continuous Current: 13.98A
Score: 80

Observations: <---- aka the TLDR
Venom Fly was an unexpected stand-out with 949mAh measured vs only 800mAh advertised, although the stated C rating on the pack is likely 'burst' which kept it out of the top spot - I will definitely be taking a look at another pack from this brand.
Turnigy took home a solid win with the highest score / closest to advertised metrics on their 3s pack.
Lancer Tactical 3s pack rather surprisingly demonstrated the ability to deliver the highest constant current of the lot. This pack is also one of the bricks which may skew the data - will test a 3s Lancer stick when possible.
Crazepony scored the lowest of the lot but if it were advertised as a 1000mAh stick it would be extremely competitive given it's low internal resistance / high discharge rate; even though it 'lost' by one metric it very well might be worth picking up anyway. May test another from this brand.

Beyond these base observations, data is to limited to contextualize the numbers and confidently state brand X is objectively 'the best' in terms of accurate labeling.


I'll close by re-iterating, I am open to testing additional batterys by popular request - it would be valuable to document commonly used packs and the occasional oddball here for community reference. I will update this thread with data for a few more packs currently in the mail plus data from a couple used packs as I find time: it takes ~2hrs minimum per pack to collect the data

 

[aotsukisho]

Thanks for doing the legwork and contributing to testing batteries. I've been putting all of my test results in the thread Guges started here if you want to take a peek at what I've tested so far. Objective Battery Test Titan LION vs. Kypom LIPO vs. HV... I have a low priority project of compiling the data into a webpage for much easier reading as I do realize my data presentation needs work for non-technical people.

Also a few things with your methodology

Balance charge new/unused LiPo w/ 1A charging current until steady 4.2v/cell

Charging should be done at 1C, not a generic rate. Most 850mAh lipos aren't able to safely be charged at 1.0A

Allow to stabilize / reach ambient temp for ~1hr

What is ambient temp? 75°F? Need to be specific

Measure Internal cell resistance, note highest individual value of 5 tests

I assume you take the average and just make note of the highest, which is good

Discharge battery fully w/ 2A max load (regulated by controller) until steady 3.2v/cell

Similar to charging, discharge testing should be a function of capacity not an umbrella choice. I understand not all chargers can handle heavy discharge loads (10W max usually) so this may be difficult. I run discharge tests at 2C, higher discharge rates will yield lower mAh and I think will better represent field usage on the workbench. Short of just running an AEG in full auto until the battery dies, I think it's a good compromise. I've managed to balloon some low quality batteries (like some Nanotech lines) even at this seemingly low amp draw so I think it's a good compromise.

Also, LVCO should be 2.5v/cell for discharge testing under load. Lipo cells are safe down to 2.5v/cell, we just set LVCO on our AEGs to >3v/cell due to the lack of taps to account for cell imbalance

In this post I will only included data from brand new / unfielded LiPo batteries
In a later post I will share data for a few batteries which have seen years of real-world use and abuse

Very good, if testing used batteries then approximate age and cycle count is necessary for proper evaluation

I do not have a standardized method to measure burst current or C rating (yet)

That's fine since it's an irrelevant number anyway.

The 'score' is the averaged summed percentage accuracy of capacity and C ratings, higher is better

I've kept these two ratings separate, as 'missing' capacity is generally better than than lower C (higher IR).

Turnigy 1200mAh 15-25c 3s 11.1v (stick) ★
Fully charged: 4.204v 4.204v 4.204v
Internal resistance: 22 25 25 (26 highest)
Fully discharged: 3.247v 3.242v 3.249v
Measured capacity: 1194 mAh
Calculated C Rating: 14.2c
Max Continuous Current: 16.95A
Score: 97

Compared to mine, your capacity was much better. Perhaps I got a mislabeled 1000mAh battery? Also our IR readings are very similar which corroborates the accuracy of our findings
IR: 22.50 22.48 22.20 mΩ
Average capacity (5 cycles): 941mAh (78.4%)
Constant C rating: 14.8C (98.9%)
Continuous A rating: 17.8A

Some of my older testing was done with 4 cycles (2 charging and 2 discharging) but the last batch I did for Guges was done over 10-12 cycles to get a wider data set. Little over 1 hour per charge cycle and 1/2 hour per discharge cycle, plus time letting the packs and equipment sit to temperature equalize...yep it's a chore.

 

[rm105]

Charging should be done at 1C, not a generic rate

Yep, but for these tests I chose 1A as this matches generic balance chargers; goal was to charge packs the same as most users will to collect 'real world' data rather than ideal/lab. Controller monitors internal temp etc so I wasn't to worried.

What is ambient temp? 75°F?

Yes.

Similar to charging, discharge testing should be a function of capacity not an umbrella choice.

Controller regulated the discharge, all I could do was set a upper limit and watch.

I've kept these two ratings separate, as 'missing' capacity is generally better than than lower C (higher IR).

My goal was to compare actual vs advertised so combining both made sense. Fortunatly everything is documented for data integration

Compared to mine

Very cool to see correlation! I have a couple duplicate packs on hand, I'll compare to see if there's natural capacity variation between them despite having similar IR. I'll have to check if we have any other packs that overlap. Just tested another 1.1Ah echo1 3s stick and the third cell IR was again ~2x cells 1 and 2, rather odd.

Indeed, but it's been interesting and my bias has been shaken which I suppose was the point. Scared to test my favorite packs lol, already making excuses

 

[aotsukisho]

Yep, but for these tests I chose 1A as this matches generic balance chargers; goal was to charge packs the same as most users will to collect 'real world' data rather than ideal/lab. Controller monitors internal temp etc so I wasn't to worried.

Generic tap-only balance chargers are generally 100-500mA charge rates though

Very cool to see correlation! I have a couple duplicate packs on hand, I'll compare to see if there's natural capacity variation between them despite having similar IR. I'll have to check if we have any other packs that overlap. Just tested another 1.1Ah echo1 3s stick and the third cell IR was again ~2x cells 1 and 2, rather odd.

Indeed, having multiple batteries of the same line will provide more data points. ID numbering them will avoid mixups

I've considered the idea of running individual cell charge/discharge cycles to determine the per-cell capacity, but I think that time is better spent running more charge/discharge cycles as a whole. Mismatched cell IR is a good indication of poor construction/QC that can be read much more quickly

Indeed, but it's been interesting and my bias has been shaken which I suppose was the point. Scared to test my favorite packs lol, already making excuses

Sadly there are very few people who are this open-minded.

 

[rm105]

Generic tap-only balance chargers are generally 100-500mA

Tenergy TN267 was my reference, the ubiquitous little silver unit we all know and love.

 

[Guges Mk3]

That Crazy Pony is the same pack on Amazon that we toasted as a Hongjie at 2000?

It was puffing and not even breaking 1000mah...after one cycle.

 

[mr. potatohead]

I'm not proud to say I bought one of those for like $30 when I didn't know any better...

 

[Guges Mk3]

I bought 4...was able to return 3 for not as advertised...

 

[rm105]

Externally it looks identical, even the same remarkably thick leads. Haven't tested it other than for data collection, was hopeful the low IR would make it actually viable as a 1Ah pack but will see if it puffs

 

[Guges Mk3]

I have noticed that anything in the "size" that is over 1400mah at 15C is "mislabeling".

 

[Huntress]

I am really happy to see Lancer's did so well. I personally run them and have had zero problems but I read/hear people bash Lancer as a brand that sucks.

 

[Guges Mk3]

Lancer Tactical 1500 20c 3s 11.1v (brick)
Fully charged: 4.204v 4.204v 4.204v
Internal resistance: 13 15 17 (19 highest)
Fully discharged: 3.257v 3.401v 3.247v
Measured capacity: 1111 mAh
Calculated C Rating: 17.2c
Max Continuous Current: 19.10A ★
Score: 80

Lancer Tactical 1300mAh 25c 2s 7.4v (stick)
Fully charged: 4.195v 4.204v
Internal resistance: 22 25 (27 highest)
Fully discharged: 3.203v 3.224v
Measured capacity: 1197 mAh
Calculated C Rating: 13.9c
Max Continuous Current: 16.63A
Score: 73

These numbers are really not that "good". You want a battery that supports around 25A and at the 30.00 price point...they should be better.

 

[mr. potatohead]

Furthermore, this whole experiment doesn't test duplicate battery packs...essentially your sample size is 1, and stats will tell you your data will be skewed...

 

[rm105]

I think we need to be careful what we call 'good' here; I set out to document how accurately individual packs were rated not how well they perform. Crazepony is a perfect example; very poorly labled so it's 'bad' from the perspective of my origional intent, but the pack has very good IR and has the 2nd highest max constant current of the lot. Lancer surprised me as well, not for the accuracy of it's lable but in it's strong performance relative to the other packs I was able to test.

I will collect and share more data in the near future, have a few duplicate packs and as mentioned a pile of well used ones I'm curious about. Just need to find the time lol

 

[Guges Mk3]

I would not recommend CrazyPony at all. It's false advertising.

I can't imagine the intricacies of telling some to buy the 3S 2000mah pack on Amazon that is really a 900mah pack that is 20C and not 30C for the price of $22.00, but it has a history of bad cells.

There is so much wrong in that.

 

[ATIS]

Finding a LIPO that fits the stock and supports 25amp discharge is the difficult part.

 

[mr. potatohead]

Finding a LIPO that fits the stock and supports 25amp discharge is the difficult part.

I gave up on that...just a fat brick velcroed under the stock.

 

[rm105]

 

[mr. potatohead]

Is that supposed to be that thing on the back of an ar pistol?

 

[rm105]

It's a brick battery stock lol, APS made them for an ARP line of AEGs. This is the small one