ISDT P20

Chargers / In use

P20 Dual Channel Smart Charger. The build's charger for the flight pack on the bench.

Image: ISDT

ISDT (Shenzhen ISD Technology Co., Ltd.)

Input

DC 10 to 34 V, 35 A max, no mains supply (it needs a DC power supply or a battery)

Channels

2

Price

$113.99 (maker's shop, 2026-10-06)

• Maker's page
• Maker's shop
• P20 Dual Channel Smart Charger User Guide login
• Original PDF (maker's site)

With the flight pack

The P20 charges the 6S2P Molicel P50B flight pack: 10 Ah, 25.2 V full, 4.20 V a cell, 10 A maximum charge (parts list, row 13). These are facts from the two sources to compare before you set a charge task:

• The P20’s LiIon preset stops at 4.10 V a cell (24.6 V for 6S). Its LiPo preset stops at 4.20 V a cell (25.2 V), the pack’s full voltage. The user guide has the full table.
• One channel gives up to 20 A and 500 W, more than the pack’s 10 A charge limit, so the charge current is the pack’s limit, not the charger’s. At 25.2 V and 10 A the pack takes about 252 W.
• The parts list’s supply for the P20 is a Mean Well LRS-600-12: 12 V, 50 A, 600 W (parts list, row 13a). On it the P20 charges one pack at the full 10 A. Two packs at once get about 7.5 A each, because the P20 draws at most 35 A, which at 12 V is about 420 W (the planner’s “12 V, 50 A” row below).
• The P20 has no mains input. It needs a DC supply of 10 to 34 V that can give the power the task takes, or a battery. Set Max. input power to the supply’s rating, as the user guide says.
• Continuous trickle is on by default: after a charge, the charger keeps a lithium pack at full voltage until you disconnect it.
• The balance current is 1.5 A a cell, and the pack’s balance lead is a 7-pin JST-XH 2.54 (parts list, row 13).

Choose a DC supply

The charger has no mains input, so its DC supply sets how fast it can charge. It draws at most 35 A, so a low supply voltage limits its power: 10 V gives at most 350 W in, 24 V gives 840 W. Above that, the supply's own power rating is the limit.

Charge current into each 6S2P P50B pack, against the supply's voltage. The shaded bands are outside the charger's 10 to 34 V input. The pack takes at most 10 A; the charger draws at most 35 A. A supply of 560 W or more gives both packs their full current from 16 V up; one pack needs about 280 W. Efficiency 90 % (ESTIMATE: ISDT publishes no efficiency for the P20).

Supply	One pack			Two packs, one on each channel
	A, set by	Storage to full (5 Ah)	Nearly empty (9 Ah)	A each, set by	Storage to full, both
12 V, 30 A (360 W)	10.0 the pack's 10 A	0 h 42	1 h 06	6.4 the supply	1 h 05
12 V, 50 A (600 W)	10.0 the pack's 10 A	0 h 42	1 h 06	7.5 the charger's 35 A input	0 h 56
Car battery, engine running (about 13.8 V)	10.0 the pack's 10 A	0 h 42	1 h 06	8.6 the charger's 35 A input	0 h 49
24 V, 15 A (360 W)	10.0 the pack's 10 A	0 h 42	1 h 06	6.4 the supply	1 h 05
24 V, 25 A (600 W)	10.0 the pack's 10 A	0 h 42	1 h 06	10.0 the pack's 10 A	0 h 42
24 V, 42 A (1,000 W)	10.0 the pack's 10 A	0 h 42	1 h 06	10.0 the pack's 10 A	0 h 42
30 V, 20 A (600 W)	10.0 the pack's 10 A	0 h 42	1 h 06	10.0 the pack's 10 A	0 h 42
36 V supply (too high for the P20)	Not usable: outside the charger's 10 to 34 V input.

Your supply

Volts Amps Set current, A Charge to add, Ah

The model: the current is the least of the set current, the channel's 20 A and 500 W, and what the supply and the charger's 35 A input give after 90 % efficiency, at the pack's full 25.2 V. The time is constant current to about 80 % charged, then a constant-voltage finish at about half that current. Both the efficiency and the finish are estimates; time a real charge and correct them. Above 10 A the set current is more than the pack's rating.

Presets on one scale

Each bar runs from the preset's discharge stop to its full charge, and the tick marks its storage voltage, all per cell. The dashed line is the flight pack's full charge, 4.20 V a cell. Source: the maker's user guide.

1.01.52.02.53.03.54.04.5

pack full 4.20 V

LiPo3.304.20

LiIon3.204.10

LiHv3.404.35

LiFe2.903.65

Pb1.902.40

NiCd/MH1.101.40

Preset	Rated	Full	Storage	Discharge	Balance charge	Cells
LiPo	3.70 V	4.20 V	3.80 V	3.30 V	yes	1 to 8S
LiIon	3.60 V	4.10 V	3.70 V	3.20 V	yes	1 to 8S
LiHv	3.80 V	4.35 V	3.85 V	3.40 V	yes	1 to 7S
LiFe	3.20 V	3.65 V	3.30 V	2.90 V	yes	1 to 8S
Pb	2.00 V	2.40 V	none	1.90 V	no	1 to 12S
NiCd/MH	1.20 V	1.40 V	none	1.10 V	no	1 to 16S

Specifications

Input voltage	DC 10 to 34 V
Max. input current	35 A
Output voltage	DC 1 to 34 V
Charge current	0.2 to 20 A, each channel
Charge power	500 W, each channel
Parallel charge (one pack on both channels)	800 W, 35 A
Balance current	1.5 A a cell, max.
Discharge current	0.2 to 1.5 A, each channel
Discharge power	15 W, each channel (30 W, 3 A in parallel)
DC power supply mode (CH1)	2 to 30 V, 1 to 5 A
Max. input power setting	100 to 1,100 W
Min. input voltage protection	10 to 31 V
Working temperature	0 to 40 °C
Size	105 × 105 × 47 mm
Mass	about 350 g

Pictures

• 

  The P20 charging two packs at once, one on each side channel. Image: ISDT.

• 

  The P20 charging one pack in parallel, its main lead on a Y cable into both outputs. Image: ISDT.

• 

  The P20's screen in DC power supply mode, 24.0 V at 5.0 A on channel 1. Image: ISDT.

• 

  The P20's system settings menu in the dark theme. Image: ISDT.

• 

  ISDT's specification sheet for the P20. Image: ISDT.