The Best 18650 Li-Ion Battery for FPV Equipment

In this post I will test various 18650 Li-Ion batteries and decide which one is the best 18650 battery for low current application. For example, powering equipment in drone racing and FPV, such as your FPV Goggles and radio transmitters.

Since I will only be using these 18650 batteries for low amp applications, I am not too concerned with max discharge current. Anything that can supply a steady 5A current would be more than enough.

I will focus on verifying the actual usable capacity of the batteries. And I will also try to test at least two different samples for each battery to get a better overview of the quality.

Further Reading: What’s the best battery for FPV goggles?

What’s the Best 18650 Battery

Please note the testing was to find the best 18650 batteries FOR MY OWN USE, I am only sharing my experience and results as I thought some of you might find it useful.

Test Candidates

I have selected these batteries because of their high capacity and good reviews. I will surely test some other batteries in the future, please let me know what  you want to see tested in the comment.

 Image Name Seller Price Weight
Panasonic NCR18650B 3400mAh Amazon $7 45.8g
LG MJ1 3500mAh Amazon $7 46.2g
Samsung 30Q 3000mAh Amazon
GetFPV
 $6.5 46.1g

Test Method

I will charge these batteries to 4.1V, then discharged them down to 3.1V with a constant 2.3-2.4A current. Data is recorded every 3 minutes, including the voltage and “mAh drawn”.

Why 4.1V and 3.1V?

You get much more cycles from 18650 cells if you use them between 4.1V and 3.1V. By charging them up to 4.1V you get roughly 2000 cycles, and that number drops to about 500 if you charge them to 4.2V.

This is what my iSDT SC620 charger does, it only charges Li-Ion batteries to maximum 4.1V. And 3.1V is the recommended “safe minimum” voltage for Li-Ion cells.

Results and Findings

I seemed to get more charge out of the Panasonic than the LG despite the lower rated capacity. And as expected, the Samsung 30Q provides the least usable capacity.

Note that we are not getting the advertised capacity because we are not charging and discharging the cells to their maximum and minimum voltages.

The Panasonic lasted the longest until the voltage reached 3.1V.

Rated Capacity mAh bet. 3.1V-4.1V Duration
Panasonic NCR18650B 3400mAh 2447mAh (72.0%) 64mins
LG MJ1 3500mAh 2377mAh (67.9%) 62mins
Samsung 30Q 3000mAh 2212mAh (73.7%) 58mins

Interestingly, the cells with higher capacity appeared to have the worse voltage sag during discharge, i.e. lower C-Rating. (Maybe that’s why 18650 batteries with high discharge current are usually lower in capacity?)

Conclusion

The weights and prices are very similar between these batteries I tested so far. Purely base on the result of this test, the Panasonic NCR18650B seems to be the best 18650 battery for low current application in FPV. They are the lightest yet they have the highest usable capacity. The LG MJ1 is not bad either, given the higher “C Rating”.

Beware of Fake 18650 Batteries

Some batteries can have exaggerated capacity, it’s rare to find batteries with capacity over 4000mAh. If you find a battery that claims to provide 10000mAh, it’s mostly likely to be fake (in some cases these turn out to be only 500mAh :) )

  • Buy from reputable sellers, check out reviews before purchasing
  • Fake 18650 batteries generally weighs less! The good ones I have come across all weighs around 40-50 grams while the fake ones weigh only half of that at around 25 grams

Charging 18650 Batteries

It’s recommended to charge your 18650 Li-Ion batteries with a dedicated Li-ion battery charger, like the iSDT C4 charger.

However you can also charge them with a LiPo charger if they support Li-Ion battery. In order to do that, you can connects the cells in series, this will allow you to charge multiple batteries at the same time – just less hassle and faster.

Don’t Solder Directly on Batteries

However, I don’t recommend soldering directly on the battery’s terminals, because overheating batteries can result in fire and explosion.

Build a DIY Case

Instead, get a battery holder and solder the connectors to it.

For example, here is how to make a case to connect 2 individual cells in series, and turn them into one single 2-cell battery. Parts list:

Pick whatever discharge connector you prefer, but you must connect the balance lead for charging. You can actually use this case to power your goggles!

You can use larger cell holder and build a 3S or even 4S case, it’s all up to you.

When charger, remember to…

  • Change battery type to “Li-ion” before charging
  • Only charge at 0.5C or lower to minimize the risk of fire

11 thoughts on “The Best 18650 Li-Ion Battery for FPV Equipment

  1. Oscar

    I use a 2s pack of 18650 sony vtc6 3120mAh to fly with a 5″. (the auw is 270gr, the battery 100gr). Motors 1306. About more than 20 min of soft flight. In Last flight the max power from all motor was 15a. Below 5.5v you must land or the quad “land” for you.
    And i use a 2s pack 18650 panasonic 3400 for the glasses. And another for the transmitter (Taranis q7x), but in this case i need to do more tests for if there are effects in power transmitted .
    Don´t like lipos, and thanks to electrical-smokers, there are powerfull 18650 models today.

    Reply
  2. Riquez

    You stated a constant 2.3A draw in your method. Is this comparable to real world use with goggles & receiver?
    The time of 64mins seems low, im sure I use my goggles for several hours in an afternoon flying. So Im wondering if the amp draw in the test is higher than general use?

    Reply
  3. Mark

    For NCR18650B, the website says unprotected. What is the meaning and the risk of having unprotected li ion (use for fatshark battery)?

    Reply
  4. rcschim

    Once again – great article here! I started to use 18650 cells in fatshark battery cage. first ones I got were horrible (only around 1000mah instead of 3000mah.
    The new ones I bought are Samsungs – and they are around 2500mah wich is fine.
    I will show this in a video soon since I tested the isdt C4 – which is a great charger for cells!

    Reply
  5. voodoo614

    Soldering to battery will generate a lot of hot. Especially if you don’t know what you are doing. Heat is bad for the battery. In addition, it will cause the battery to puff. Unlike the Lipo we use that is encase in slightly expendable wrap, Li-io is encased in a hard case. It can explode or cause fire.

    That is why manufacturers do not solder packs together. They use spot welding.

    Reply
  6. Oscar Post author

    I don’t think there is anything that needs to be changed. The whole purpose of this test is to find the battery that can give me the longest battery life for powering my FPV goggles, and it did.
    Meaningless? Please read my post again, there is so much info you can extract from those graphs.
    This test was meant to determine the best battery for my own use, I am only sharing my result because I thought someone might find it useful. Take it as a grain of salt if you don’t think it’s good enough for you.

    Reply
  7. Harry Herring

    You don’t need to set the charger to li-ion, regular lipo setting works fine on 18650’s, they can handle 4.2v max no problem

    Reply
    1. Oscar Post author

      I haven’t verified this myself, but I read somewhere you get more discharge cycles out of the battery if you charge them up to lower voltage such as 4.1V vs 4.2V… The difference is 800 cycles vs 400 cycles.

      Reply

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