Is Romoss Power Bank Safe?

Power bank explodes

This morning, my girlfriend forwarded a message about the exploded of a Romoss Power Bank.

I was a little surprised because I just bought two Romoss power banks half a year ago, one for each.

Then I began to search for answers of this brand.

Comment 1: Everyone has experiences of an exploded power bank.

Comment 2: Used for X years without it being exploded.

Comment 3: Probability event of getting a bad batch.

Comment 4: Various conspiracy theories.

Until I saw a reliable article, that pointed out that the Romoss power bank does not have temperature monitoring.

I started searching for the ROMOSS LT20 PowerBank teardown.

Romoss   open 2 Open

The inside of the power bank.

There are only two wires connecting the positive and negative ends between the PCB board and the battery.

The full teardown article did not mention about its temperature monitoring.

Then I searched for teardown evaluations of other power banks.

Xiaomi Mi Power Bank 3

The core manufacturer is ATL, which is made up of 2S PACK, i.e. two series of power cells, with a single full voltage of 4.35V discharge platform 3.7V ,  37Wh.

The yellow high temperature-resistant tape on the side of the battery pack can be seen, with the NTC temperature probe deeply inserted in the middle of the two cores, the probe is buried in silicone to conduct heat more efficiently, used to disconnect the output when overheat, provide overheat protection.

Xiaomi mi powerbank 3

xiaomi powerbank 3 teardown

Meizu M10 Powerbank

A barrier of sponge to avoid electricity leakage to the casing.

meizu power bank

Temperature-controlled protection probe.

Meizu powerbank m10

OnePlus Power Bank

Two protection circuits consisting of ANO 3814 and VZTL.

Oneplus powerbank

Red Color Temperature-controlled protection probe.

Oneplus powerbank

Sony CP-V10 Powerbank / Portable Charger

sony powerbank

Main control is Sinwealth SH79F1615P, which integrates ADC and PWM.

Sony Powerbank

The CP-V10 also has thermistors for overheat protection

Sony Power bank

ZMI Power Bank

ZMI Power Bank

Protection circuit

ZMI Power Bank

The thermistor is arranged similarly as Xiaomi Power Bank.

Whether it’s safe or not, you decide.