Comparison

PROJOY M vs HERF Battery

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head

About

PROJOY M

Features

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PROJOY M-Cloud V2 is a solar plant monitoring application used by endusers or installers for Projoy products. You are able to manage different plants add devices, configure the devices in batch, review real-time and historic power generation data, calculate your yield on your mobile phone. In addition, you are able to build a layout of your solar panels and monitor the perfomance of each panel individually.

About

HERF Battery

Features

Read full description

HERF Battery is a mobile application specially designed for balcony solar battery systems. It not only provides customers with a more convenient funtion of adding device and consise visual interface, but also enables to set personalized discharge time, helping users better manage the system.

Screenshots

PROJOY M4 screens

HERF Battery3 screens

Verdict

The call

The clearest difference is update cadence: HERF Battery at every 2 days against PROJOY M's every 4 months. HERF Battery also leads on iOS requirement (11.0 vs 13.0). On price, ads, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

PROJOY M ships an update every 4 months, HERF Battery every 2 days. The most recent releases landed on September 17, 2026 and September 9, 2026 respectively.

Scorecard2 real differences · 4 level

PROJOY M versus HERF Battery: the parameters behind the verdict, then further details
Parameter	PROJOY M	HERF Battery
Price	Free	Free
Update frequency	Every 4 months	Every 2 days — better
Ads	No	No
In-app purchases	No	No
Devices	iPhone, iPod	iPhone, iPod
Requires iOS	13.0	11.0 — better
Further details — not scored
Size	40 MB	94 MB
Age rating	4+	17+
Developer	Projoy Electric Co., Ltd.	JUAN WANG

In-app purchases

None

PROJOY M

No in-app purchases

None

HERF Battery

No in-app purchases

Questions

Is PROJOY M free?

PROJOY M is free to download, with no in-app purchases.

Is HERF Battery free?

HERF Battery is free to download, with no in-app purchases.

Do PROJOY M or HERF Battery have ads?

Neither PROJOY M nor HERF Battery shows ads.

Which is updated more often, PROJOY M or HERF Battery?

PROJOY M ships an update every 4 months, and HERF Battery every 2 days. Most recently, PROJOY M was updated on September 17, 2026 and HERF Battery on September 9, 2026.