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EOS Sentry4 2~8S Battery Checker Balancer,

The EOS Sentry 4 is a quick, clever, and convenient device for checking your battery voltages. This handy little voltage meter is compatible for use with Lipo, LiFe, Li-Ion, as well as NiMH and NiCd batteries. The Sentry 4 shows at a glance the remaining capacity in your LiPo battery pack, cell balance, cell voltages and difference between cells. A unique feature of the Sentry 4 is it's Stand-alone Balance and Discharge Mode for Lithium batteries which is convenient for storing fully-charged packs down to 3.8v. Furthermore, the Sentry 4 also boasts a Servo and ESC tester by connecting a external power supply you can control and test the Servos frequency, Servo test range and ESC settings.

Product details

The Sentry 4 provides you with all information and tools necessary to maintain and keep your packs performing. Avoid costly mistakes and increase battery reliability by using a high-quality battery checker.


2S ~ 8S Lithium Battery compatible with HvLi LiPo, Standard LiPo, Li-Ion and LiFe
4S ~ 8S Ni-Cd/MH batteries support
Built-in Servo and ESC Tester
EOS Sentry 4 displays the total battery pack voltage and a percentage bar graph for estimated remaining capacity.
View screens for Minimum and Maximum cell voltages, and voltage difference between max and minimum cell.
Convenient Balance and Discharge function.
Parameter settings
Clear display and easy-to-use menu
Powered from the battery pack you connect for testing. No batteries needed for device.
Dimension: 85.4 x55 x 16mm
Weight: 52.4g
Lithium battery input: 2S - 8S (HvLi LiPo, Standard LiPo, Li-Ion and LiFe)
Nicd/NiMH input: 4S-8S
Discharge cut-off setting range: 2.000 - 4.200V
Servo Test Frequency setting: 50Hz, 60Hz, 100Hz, 125Hz, 200Hz, 250Hz and 300Hz
Servo Test Signal Range setting: 500 - 2500us or 1000 - 2000us
Sound switch setting: on , off
This battery checker is compatible with JST-XH balance adapter
WARNING: Do not keep your battery connected to the Sentry4 for long periods of time. Since this unit is powered from battery source, the parasitic draw while on standby will consume your battery, thus your battery will over-discharge. Once discharged and stored, disconnect the Sentry 4.

For Servo & ESC tester function, we suggest to use with 1000 - 2000 pulse setting. Also please set frequency value at 50Hz if you are not sure your servo's specific frequency.

Estimated remaining capacity percentage "%" is only a guide so please judge by remaining voltage.