GT Power LiPoly Low Voltage Alarm — 2S/3S
GT Power LiPoly Low Voltage Alarm — 2S/3S
A dead LiPoly battery is an expensive mistake. An over-discharged one is worse. The GT Power Low Voltage Alarm protects your 2S and 3S LiPoly packs by sounding a loud audible buzzer and flashing an LED the moment any cell drops to 3.3V — early enough to stop and recharge before you damage the pack permanently. Weighs 3.3 grams. Fits anywhere. Costs less than a battery. In stock and ships from the US.
- Compatibility: 2S and 3S LiPoly batteries
- Alarm threshold: 3.3V per cell (6.6V on 2S / 9.9V on 3S)
- Indicators: Blue/red LED + audible buzzer
- Dimensions: 13 × 25 × 11mm (0.51 × 1.0 × 0.43in)
- Weight: 3.3g (0.12oz)
$8.99
27 in stock (can be backordered)
Protect Your LiPoly Pack
Over-discharging a LiPoly battery doesn’t just shorten its life — it can kill the pack permanently. LiPoly cells pushed below their minimum voltage suffer irreversible damage to their chemistry. One deep discharge at the wrong moment and a battery that cost you $15 is a paperweight. The GT Power Low Voltage Alarm monitors your 2S or 3S pack in real time and warns you before you cross that line.
How It Works
Connect the red and black wires to your battery’s positive and negative terminals — on the bot side of your power switch, so the alarm is live when the bot is running but draws nothing when it’s switched off. Select 2S or 3S with the built-in slide switch. The blue LED stays solid above safe voltage, begins flashing as the pack runs low, shifts to red as the threshold approaches, and triggers both a flashing red LED and a loud audible buzzer when any cell hits 3.3V. You’ll hear it across the arena.
LED Indicator Reference
2S mode: Blue solid ≥7.4V | Blue flashing 7.4–6.8V | Red solid 6.8–6.6V | Red flashing + buzzer below 6.6V
3S mode: Blue solid ≥11.1V | Blue flashing 11.1–10.2V | Red solid 10.2–9.9V | Red flashing + buzzer below 9.9V
Small Enough to Go Everywhere
At 13 × 25 × 11mm and 3.3 grams, this alarm disappears inside any combat robot. Adhesive-backed foam is included so you can mount it without tools. Wire length is 9.53cm (3.75in) — enough reach to find a clean tap point without adding unnecessary slack inside a tight chassis.
In Stock — Ships From the US
We stock these because every bot that runs a LiPoly pack should have one. In stock here means it ships from our US location — no long wait, no customs delays. Build question? Email us: info@itgresa.com. A builder answers.
Features
- Protects 2S and 3S LiPoly packs — single slide switch selects cell count; one alarm covers both pack sizes
- Audible + visual alarm — loud buzzer and flashing red LED trigger when any cell drops below 3.3V; you’ll hear it before damage occurs
- Progressive LED status — blue solid, blue flash, red solid, red flash + buzzer; pack voltage at a glance at any point during a run
- Wires to main power leads, not balance port — tap on the bot side of your power switch so the alarm draws zero current when the bot is off
- Tiny and light — 13 × 25 × 11mm, 3.3 grams; fits inside any antweight or fairyweight build
- Adhesive-backed foam included — mount without tools, no fasteners required
- In stock, ships from the US — no long overseas wait, no customs delays
Specifications
| Specification | Value |
|---|---|
| Compatible Batteries | 2S and 3S LiPoly |
| Alarm Threshold | 3.3V per cell (6.6V on 2S / 9.9V on 3S) |
| Alarm Type | Audible buzzer + LED (blue/red) |
| Dimensions | 13 × 25 × 11mm (0.51 × 1.0 × 0.43in) |
| Weight | 3.3g (0.12oz) |
| Wire Length | 9.53cm (3.75in) |
| Cell Selection | Slide switch (2S / 3S) |
| Connection | Red/black wire leads to battery terminals |
| Mounting | Adhesive-backed foam included |
| Manufacturer | GT Power |
Frequently Asked Questions
Why do I need a low voltage alarm?
LiPoly batteries discharged below their minimum safe voltage suffer permanent, irreversible cell damage. Even one deep discharge event can destroy a pack. A low voltage alarm warns you before you cross that threshold — giving you time to stop and recharge. At under $9, it costs far less than a replacement battery.
How do I wire this alarm?
Connect the red wire to your battery’s positive terminal and the black wire to ground. The best tap point is on the bot side of your power switch — this way the alarm is live when the bot is on, but draws no current when the switch is off. Wire it the same way you’d connect an ESC: red to positive, black to ground.
How do I select 2S or 3S mode?
Use the built-in slide switch on the board. Set it to 2S for 2-cell packs (7.4V nominal) or 3S for 3-cell packs (11.1V nominal). The alarm threshold is 3.3V per cell in both modes — 6.6V total on 2S, 9.9V total on 3S.
What do the LED colors mean?
In 2S mode: blue solid (≥7.4V, all good) → blue flashing (7.4–6.8V, running low) → red solid (6.8–6.6V, getting close) → red flashing + buzzer (below 6.6V, stop now). 3S mode follows the same pattern scaled up: ≥11.1V, 11.1–10.2V, 10.2–9.9V, below 9.9V.
Will it fit inside my antweight or fairyweight?
Almost certainly. At 13 × 25 × 11mm and 3.3 grams, this is one of the smallest alarms available for this application. The adhesive foam backing lets you stick it to any flat interior surface. Wire length is 3.75in — plenty of reach inside a 1 lb or 150g robot.
Does this work with balance port connectors?
No — this alarm connects to the main power leads, not the battery’s balance port. This is an advantage for in-robot use: you tap into the same wiring your ESCs use, and the alarm draws zero current when your power switch is off.
