Generac — Battery Voltage Drop Test
Testing & diagnosis · Battery and cables
From a Generac service manual covering: 10 KVA, 13 kVA, 8 kVA. Check it applies to your exact model before use.
Applies to: Generac EcoGen 6 kW, Generac GH-410 engine, Generac GH-426 engine, Generac GT-530 engine, Generac GT-530 engine, Generac GT-999 engine, Generac OHVI engine
Parts for this job
- 0H3421S Battery Amazon eBay $283.32
Part numbers from the service-parts list for Generac EcoGen 6 kW. Verify against your serial number before ordering; some links are affiliate links.
Procedure
- Remove T1 fuse.
- Set DMM to DC voltage.
- Connect leads to battery posts.
- Set controller to MANUAL.
- Measure voltage drop at test points V1-V4.
- Compare to specs.
Tools required
- DMM Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Max 0.00-0.10 VDC across connection
- 0.10-0.20 VDC ground connection
- 0.20-0.30 VDC across wire or cable
- 0.20-0.30 VDC across switch or starter contactor
- 0.40-0.50 VDC across entire circuit
Full service-parts list: Generac EcoGen 6 kW →
Source: Generac service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.