Surveyor2 vs StandbyCalc Battery Calculator
Price, ratings, monetisation and update history for both apps, side by side โ with what reviewers say about each.
Surveyor2
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Live device states for IoT enabled Quantec systems using surveyor 2
StandbyCalc Battery Calculator
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StandbyCalc works out the standby battery you need for UK fire and intruder alarm systems in seconds. Enter the quiescent and alarm currents, pick the fire alarm category or the intruder alarm grade, and get the minimum battery capacity in Ah plus the next standard SLA battery size. Add the fitted battery to see whether it's above or below the calculated minimum. Every battery calculation is free. No ads, no tracking, no sign-up and no subscription. FIRE ALARM BATTERY CALCULATION - Based on BS 5839-1 - Categories L, M and P - 24 h standby, or 6 h where a standby generator is fitted - Category P premises left unoccupied: standby periods up to 72 h INTRUDER ALARM STANDBY - Based on BS EN 50131 and BS 9263, Grades 1 to 4 - BS 4737 (legacy systems) for older installations - Standby battery sizing for control panels and remote power supplies PSU AND SLA BATTERY SIZING - Standalone 12 V and 24 V power supplies with your own standby and alarm periods - Minimum Ah with de-rating applied, rounded up to the next standard SLA battery HOW IT WORKS 1. Enter the panel and device currents for standby and alarm 2. Choose the system type, then the category or grade 3. Read off the minimum capacity and the SLA battery to fit 4. Optional: enter the fitted battery to see if it's above or below the calculated minimum The working is shown in full: C = 1.25 x (I1 x T1 + D x I2 x T2) NEW IN 1.0.5 - Fitted battery: enter the fitted Ah and battery date, see whether it's above or below the calculated minimum, and copy a one-line result for your service sheet (free) - Fitted battery line on PDF reports (Pro) - BS 4737 now labelled "BS 4737 (legacy systems)" STANDBYCALC PRO (one-off ยฃ9.99) - Redesigned branded PDF reports with your logo - Full formula working on every report - Save calculations against a site and come back to them later - A clear PDF record of each calculation for your job file Built for UK fire and security installers, engineers and maintainers who need a quick standby battery calculation on site. Always check results against the panel and battery manufacturer's data. From D4N LTD. Support: https://d4n.io/projects/standbycalc/ Independent app, not affiliated with or endorsed by BSI.
Screenshots
Verdict
The clearest difference is in-app purchases: Surveyor2 at none against StandbyCalc Battery Calculator's 1. On price, update cadence, ads and device support there is nothing between them.
Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS
Both are free to download. StandbyCalc Battery Calculator sells 1 one-off in-app purchase. Surveyor2 asks for nothing beyond the download.
Surveyor2 ships an update every 2 months, StandbyCalc Battery Calculator every 5 weeks. The most recent releases landed on October 16, 2026 and October 24, 2026 respectively.
| Parameter | Surveyor2 | StandbyCalc Battery Calculator |
|---|---|---|
| Price | Free | Free |
| Update frequency | Every 2 months | Every 5 weeks โ better |
| Ads | No | No |
| In-app purchases | No โ better | Yes |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 17.6 | 17.0 โ better |
| Further details โ not scored | ||
| Size | 47 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | C-TEC (Computionics) | D4N LTD |
In-app purchases
Surveyor2
No in-app purchases
StandbyCalc Battery Calculator
- StandbyCalc Pro$9.99
Questions
Is Surveyor2 free?
Is StandbyCalc Battery Calculator free?
Do Surveyor2 or StandbyCalc Battery Calculator have ads?
Which is updated more often, Surveyor2 or StandbyCalc Battery Calculator?
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