In this guide 6 sections
Record the bank on the day it goes live: cell or block voltages, specific gravity or internal resistance, charger settings, room temperature and a timed load test. Sign it and file it by serial number. Later complaints can then be compared.
Why day one is the only baseline you get
A customer calls eight months later and says the backup time has dropped. Without a starting record you cannot tell a weak cell from a bad charger setting or a load that has grown.
On day one the bank is new, the settings are yours and the site is clean. Every later reading is a drift from that moment. If you did not write it down, the moment is gone.
The record also protects you. A float voltage set by a visiting electrician last month shows up against the value you left.
Identity and installation details
Start with who and what. Customer, site, installer, date, and the battery make, model, chemistry and capacity. Add the serial number of each unit and the manufacture date code printed on the case or label.
Photograph the nameplate, the rack and the cable layout before closing the cover. Note the room temperature and whether ventilation is blocked, because heat shortens battery life.
Record the connected load and the wiring. Cable size, lug torque, and fuse or breaker ratings matter when a terminal later turns black.
- Serial numbers and date codes for every unit
- Photos of nameplate, rack and terminals
- Room temperature and ventilation notes
- Connected load and cable sizes
Measurements to take before the first discharge
Measure open circuit voltage on every cell or monobloc after the bank has rested, and write each reading against its position number. For flooded cells add specific gravity with the electrolyte temperature. For sealed lead acid, lithium or gel types, record internal resistance or conductance if your tester allows it.
The spread matters more than the average. One cell sitting far from its neighbours on day one is a warranty question you should raise immediately, not a mystery to solve a year later.
Take the string voltage and note the polarity check. A reversed link is easy to make and hard to find afterwards.
Charger settings and the load test
Photograph the charger or inverter settings screen. Write down float voltage, boost or absorption voltage, current limit, low voltage cut-off and any temperature compensation. These numbers explain most early failures.
Then run a timed load test at a known load. Record the start voltage, the load in watts or amps, the time to reach the cut-off, and the voltage at fixed intervals. A short test is better than none.
Recharge fully and note the recharge time. A bank that takes far longer to recharge next year tells its own story.
- Float, boost and cut-off voltages
- Current limit and temperature compensation
- Test load, duration and voltage at each interval
- Recharge time and final float current
Use the record when the complaint arrives
File the sheet by customer and bank serial, in a place the service team can open from the customer’s phone call. Attach the photos to the same record.
At each service visit, repeat the same short set of readings in the same order. Put the two sheets side by side. The weak cell, the changed setting or the heavier load will be obvious.
Make the day-one sheet a condition of closing the job. No signed record, no completion certificate.
Battery bank commissioning sheet
The form has four blocks. Block one holds customer, site, make, model, chemistry, capacity, serials and date codes. Block two is a table of cell or block positions with voltage, specific gravity or resistance and temperature. Block three holds charger and inverter settings. Block four holds the load test log with time, voltage and current, and signature lines for engineer and customer.
Open a blank worksheet to printQuestions owners ask
Do I need specific gravity for every battery type?
No. It applies to flooded lead acid cells. For sealed and lithium types, record voltage and internal resistance or conductance if you have a tester, plus the management system readings.
How long should the commissioning load test run?
Long enough to show a steady discharge curve at a known load, without harming a new bank. Follow the maker’s guidance for the first discharge.
Where should the record be stored?
Against the bank serial number in the customer record, with photos attached, so anyone in service can find it without calling the original engineer.
Should the customer sign it?
Yes. A signature shows the settings and readings were agreed on the day, which settles later arguments about who changed what.