Batteries and connectors
Cell count sets the voltage everything else has to tolerate, and the connector sets how much current can get through before it becomes the weakest part of the aircraft.
Cell count is the number that constrains everything
A lithium-polymer pack is described by how many cells it has in series: 1S, 2S, 4S, 6S. Each cell contributes a nominal 3.7 V and a fully charged 4.2 V, so a 6S pack arrives off the charger at 25.2 V.
Every part that touches the battery has a voltage range it tolerates. An ESC rated to 4S is destroyed by a 6S pack, so this is a hard compatibility rule rather than an advisory one. Your charger has the same constraint from the other side: it supports a range of cell counts, and a pack outside it cannot be balance-charged.
- How to Choose FPV Drone MotorsOscar Liang · Editorial · read 2026-07-27
Connectors
Roughly in order of size. The current figure is what the connector itself will pass continuously.
| Connector | Continuous current | Typical use |
|---|---|---|
| PH2.0 | about 2 A | 1S whoop |
| BT2.0 | about 9 A, peaks near 15 A | 1S whoop, noticeably less voltage sag than PH2.0 |
| A30 | not confirmed | 1S and 2S micro |
| GNB27 | not confirmed | 1S micro |
| XT30 | about 30 A | 2S whoop, toothpick, 3–4 inch |
| XT60 | about 60 A | The de-facto standard from 3 inch up, and standard at 4S and above |
| XT90 | higher still | Large and long-range builds |
- Testing A30, BT2.0, PH2.0, GNB27 and XT30 connectorsOscar Liang · Editorial · read 2026-07-27
Connector mismatch is a warning, not a refusal
A battery whose plug does not match the aircraft is a soldering job, not a dead end, and pigtail adapters are sold for every common pair. So Buildlas reports this as a warning rather than an incompatibility: it is something to know before the parcel arrives, not a reason to choose a different battery.
Voltage range is the opposite. There is no adapter for handing an ESC more volts than it tolerates.
- Testing A30, BT2.0, PH2.0, GNB27 and XT30 connectorsOscar Liang · Editorial · read 2026-07-27
See this against real products
The planner reads these same properties off every product in the catalog and tells you what each pairing does with your build.