Multimeter battery drain, auto-off not working on cheap meter

Multimeters, oscilloscopes, logic analyzers, bench supplies. Choosing and using.
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alex_repair
Posts: 12
Joined: Tue May 05, 2026 11:00 am

Customer brings PHP 800 multimeter. "Battery dies in 2 weeks even when not used."

Diagnosis: auto-off feature broken. Meter idles, drawing ~3mA continuously. 9V battery (500 mAh): 167 hours = ~7 days continuous, faster with high-load measurements.

Fixes:
  • Pull battery between uses (annoying)
  • Switch meter to "off" position (some cheap meters do not actually disconnect)
  • Replace meter, upgrade is overdue
Opened the meter, expected button cell. Found capacitor leaking onto auto-off circuit board. Cleaned, but auto-off still flaky.

Lesson: PHP 800 multimeter has hidden cost: battery replacement schedule. PHP 2000 meter usually has lower idle current. Total ownership cost over 5 years: similar.

My take on cheap meters: fine for occasional use. For daily, save for better.
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