Lutron Sivoia QS Application Note: Alkaline Battery Screening and Diagnosis (048562, rev A)

Facts Lutron states in 048562

The values Lutron document 048562 states, as published:

Recommended testers

ZTS Pulse-Load multi-battery testers MBT-1 and Mini-MBT. Both test alkaline D cells, only the MBT-1 tests lithium AA cells

What the tester reads

Terminal voltage under a known load, shown as state of charge in 20% steps. Bar graph of 6 LEDs on the MBT-1, 5 on the Mini-MBT

Acceptance for new batteries

Every battery going into a shade must read 100% out of the package

Why one battery matters

Shade batteries run in series, so one weak battery limits the whole stack. The shade hibernates on purpose to stop the weak battery over-discharging and leaking

Test method

Positive end (raised bump) held on the front terminal, black negative lead touched to the flat end

When to diagnose

Shade moving at half speed, slow red blink or solid red LED. Test each battery and look for the one reading lower than the rest

Replacement rule

All brand-new batteries from the same manufacturer, preferably from the same package

Normal readings

80% shortly after installation is normal. 20% after low battery feedback is normal, a reserve for hibernation, feedback, listening for radio commands and avoiding leakage

Signs of a defective battery

Readings of 20% to 40% early in life, readings that change erratically, or readings that rise over time

Example stacks

Figure 4.1 shows six-battery stacks on the MBT-1 6-LED graph in nine cases. Well matched, poorly matched and latent defect stacks, each new, partly discharged and dead

Latent defects

Lower capacity can develop after a few months, even in a new, high-quality, well-matched set from a reputable maker