Video: IBAR

Video transcript

What the IBAR measures in a battery, how the probes go on each cell, and how a whole bank is tested and turned into a trend. A backup battery can show a normal voltage and still be failing. Its internal resistance rises as it ages, long before the voltage shows anything. Measured cell by cell and compared over the years, it points at the cells to replace. Resistance from zero to 5 ohms in 4 ranges, down to one micro-ohm, and voltage up to 60 volts.

About two seconds per reading, in half a kilo. Everything is done from the front with one hand: the display, the power and backlight keys, the range key in the middle, and MEM, SET, ENTER and the arrows to move through the menus. The test leads plug into one four-pin connector on top: two wires inject a one kilohertz test current, and two sense the voltage. At the bottom, the charger input and the USB port. In the case: the power adapter, the PC software with its USB cable,

the test lead set with pin probes, and the zero calibration board. Angled probes are an option. Four checks first. The battery, for damage or leaks. The instrument and its leads. The battery offline, away from charger and load, which is what makes the readings repeatable. And no flammable gas, because a probe can spark. For one cell: the lead into the instrument, the red probe on the positive terminal, and the black probe on the negative of the same cell.

In U plus R mode, resistance and voltage come in one reading. The same probes check the link between two cells: black on the negative of one, red on the positive of the next. A loose or corroded strap reads higher than its neighbours. U plus R measures resistance and voltage together, because resistance depends on the state of charge. U mode reads voltage only, to support a capacity test. The range is found automatically, or set by hand.

SET opens the settings. Test settings choose the mode and the string and test numbers. Then the clock, the comparator, the automatic functions, and the general menu, where the zero adjustment lives. The comparator gives a verdict. Enter the reference resistance, the warning and fail limits as a percentage above it, and a reference voltage. Each cell is then flagged pass, warning or fail as it is measured.

Zero adjustment removes the leads' own resistance. Stand both probes upright on the zero board, spaced like the battery terminals. It runs through every range in about 20 seconds, with a pass or fail for each. Then testing a bank is a walk along it. Choose the string and the test, place the probes, and read. Auto hold keeps the result, and auto save stores it and moves on to the next cell number. Over USB, the PC software imports the tests.

Cells past the warning limit turn yellow, past the fail limit red. Histograms, trend charts and reports follow, in Excel, PDF, Word or RTF. If the readings look doubtful, check the instrument on a known shunt. At 3 milliohms, the reading should fall between 2.965 and 3.035. Three warnings. Overload: the value is above the fixed range, so choose a higher one or auto. Overvoltage: more than 60 volts. Bad connection: a probe is not touching the zero board.

It is made for stationary batteries: substations, power plants, protection and control, telecoms, UPS systems and data centres, in lead-acid, VRLA, nickel-cadmium or lithium. Battery testing, from Amperis.