Need two batteries to start JD LT 166

   / Need two batteries to start JD LT 166 #11  
The meter registers 12.4v on my other three 12v batteries. Would the meter not work on the one battery?

No - the meter is fine. It’s that one battery that’s reading 3.8v that is screwy.

If it were me, I’d consider that 13.8v battery to be bad.
 
   / Need two batteries to start JD LT 166 #12  
The meter registers 12.4v on my other three 12v batteries. Would the meter not work on the one battery?
no your battery has a issue, prolly sulfated. if you use a different battery does it start without issue?
 
   / Need two batteries to start JD LT 166 #13  
You might want to invest in a decent battery tester, I bought one of these a few years ago and find it to be very useful. It tests the CCA of the battery and will tell you if the battery is bad, or just needs to be re-charged.
1691463084568.png
 

Tractor & Equipment Auctions

2016 Ford Escape SUV (A56859)
2016 Ford Escape...
NEW Skid Steer Attachment Plate (A59000)
NEW Skid Steer...
1990 MACK RD688S (A58214)
1990 MACK RD688S...
2021 Boss 990 Fuel Trailer, VIN: 1F9BT1028MB503652, Honda GC 160 Gas Fuel Pump, Tandem Axle, GVWR: (A59076)
2021 Boss 990 Fuel...
205196 (A52706)
205196 (A52706)
Mini John Deere Truck (A55853)
Mini John Deere...
 
Top