Cutting through the marketing hype and exposing the good, bad, and ugly.
We all know how important the right battery is. There are many opinions out there, and even more batteries. Is it worth spenind more on the big name brands? Do the budget brands deliver enough performance? This review looks at a few of the most popular batteries and uses some real world ways to evaluate them alongside some objective tests.
C ratings have become all but useless. How much trust should you put in them? What brands are more honest than others? Are any actually accurate?
The Batteries Tested
The batteries that have been tested are:
- Nanotech 1300mah 45C 3S
- Multistar 1400mah 40C 3S
- Lumenier 1300 60C 3S
- Lumenier 1300 35C 3S
- SMC 2800 65A "True Spec" 3S
This is not meant to be a scientific approach with lots of detailed charts and graphs made using complex hardware. Rather it is designed to be something you can do yourself, yet still provide meaningful and comparable data.
Each battery is charged using a Turingy Reaktor charger (functionally the same as the iCharger chargers, same firmware and nearly identical hardware). Batteries are balanced charged to 4.2V, then left to stabilize at 75-80F for one hour. After this time the Internal Resistance (IR) is taken 5 times. The lowest values for each cell are what are used here. IR is at its best when the battery is fully charged and the battery is warm. 77F is what is generally considered the standard temperature to use. 75-80 is the average indoor room temperature so provides a good range others can use.
The battery is then flight tested. For these tests a mini FPV quad-copter was used:
- E-Max Nighthawk Frame
- DYS 1806 2300KV motors
- ZTW 12A ESCs
- Dragonfly32 Pro Flight controller with Cleanflight with telemetry enabled
- FrSky Taranis and D4R-II
- 200mw VTX and Sony 600TVL camera
- DAL 5045 props
- All Up Weight (AUW) of 520 grams.
Testing has two phases. The first is a simple hover test. The model was hovered 6-8 feet off the ground for 5 minutes. 5 minutes was chosen because the battery voltage is left very close to storage level and its a nice round number. A second flight test is then conducted where it is flown in a circuit at the local soccer field. Flight is only 10-20mph. The hover test produces an average current of 8 amps. The forward flight test produces an average current of 10 amps with 20A burst. The max amps measured on full throttle punch outs is about 30 amps. These are well within the ratings of all these batteries.
During each flight the Taranis was programed to report when the voltage dropped below 11.1V (3.7V per cell) and 10.8V (3.6V per cell). The time at which this occurred was recorded. This indicates how the battery handles the load and how much the voltage sags.
After the flight the battery temperature was taken and the highest recorded value is recorded.
Each test was conducted multiple times. The results posted are averages or ranges taken from these multiple tests.
Nanotech 1300mah 45C ($15)
Turnigy Nanotech batteries are loved and hated by many. Some praise them for their value and performance. Others love the value, but tolerate the waning performance as they age. Others hate them and avoid them at all costs. In this test this pack did quite well.
The advertised weight was conservative, this one weighed 116g.
Out of the box the IR was 6/6/8. After a few charging cycles this settled in at 6/6/6.
It would make it to the full 5:00 mark without triggering the voltage warning (either 3.7 or 3.6) in the hover test. The forward flight test was similar, making it 4:15 before the initial alarm at 3.7V. It did not hit 3.6V in flight. Final resting voltage was 3.77V.
The battery temperature was quite good. Even in upper 90F heat the battery was barely above ambient at 99F. On cooler days with 75-80F temperatures it measured in at 80-84F.
This pack performed very well. It never felt like it was losing power and balances very nicely when charged. This is clearly a good value, however long term health is an area of concern and will be monitored (one of the common complaints).
Multistar 1400mah 40C ($16 )
The Multistar line of batteries are Hobby King's multi rotor specific line of components. Most of the Multistar batteries are 10C for the low amp needs of larger multi rotors. However the huge mini quad market demands an exception, and thus we get this 40C variety. It is really just a rebrand of their popular 1400mah 40C battery for the car market. They put a new color shrink wrap, and new label, and a useless XT30 connector on it and viola. The Multistar 40C 1400mah.
Advertised weight is accurate at 115g.
Out of the box the IR was 6/6/6. After a few charging cycles this settled in at 5/6/5.
It would make it to the full 5:00 mark without triggering the voltage warning (either 3.7 or 3.6) in the hover test. The forward flight test was similar, making it 4:30 before the initial alarm at 3.7V. It did not hit 3.6V in flight. Final resting voltage was 3.79V.
The battery temperature was also quite good. It was 101F with an ambient of 96F.
This pack also performed very well. It never felt like it was losing power and balances very nicely when charged. This is clearly a good value, however long term health is an area of concern and will be monitored (one of the common complaints). The only issue is the absurd XT30 connector. XT60 is practically the standard that Hobby King established. The battery is theoretically capable of 56 Amps (1400 mah x 40C), yet it uses a connector rated at 30A constant?
Lumenier 1300mah 35C ($17)
The Lumenier line of batteries are GetFPV's in house batteries.
Advertised weight is accurate at a category best 100g.
Out of the box the IR was 13/12/14. After a few charging cycles this settled in at 12/12/14. Already this one shows some cause for concern. Clearly it gets that 100g weight by using lower quality cells. But does this IR reading translate to reduced performance?
Yes. This one had some clear performance issues. It would only make it to the 3:30 mark before triggering the 3.7V warning in the hover test. The forward flight test was worse, making it 3:00 before the initial alarm at 3.7V, then at 3:30 it triggered the second 3.6V alarm. Final resting voltage was 3.77V.
The battery temperature was warmer than the others. It rose to 108F with an ambient of 96F.
This pack did not perform very well. It felt like it was losing power after a few minutes. The hover value was 42% compared to 35% for the other packs. This shows it takes more throttle to get the same rpm/lift. Flight times show that any efficiency gains from the light weight are lost with the voltage sag. As one of the more expensive options, it is not a good value.
Lumenier 1300mah 60C ($22)
The Lumenier line of batteries are GetFPV's in house batteries, and this is the premium line.
Advertised weight is accurate, but at a category worst 119g.
Out of the box the IR was 5/6/7. After a few charging cycles this did not change.
This one was much better than its 35C cousin. It would not trigger any of the alarms in the hover test. The forward flight test was good, making it 4:30 before the initial alarm at 3.7V, and never triggering the second 3.6V alarm. Final resting voltage was 3.78V.
The battery temperature was good, rising to 101F from an ambient of 96F.
This pack did perform very well, similar to the Nanotech and Multistar. However at $6-8 more is it worth it? Time will tell if the Nanotech or Multistar don't hold up.
Here is a chart of the test data. As you can see, the cheapest options provide the best performance (matched by the more expensive 60C Lumenier) and appear to offer the best value.
The Nanotech and Multistar are the leaders when you consider cost. The Lumenier does have the edge with the numbers if you don't care about cost or get free batteries. For most of us, cost matters so they would rank:
- Nanotech 45C
- Multistar 40C
- Lumenier 60C
- Lumenier 35C (its poor performance ranks it below the more expensive 60C version even for value)
What is next?
More batteries and some objective bench top testing with discharge curves at various loads.