# Battery fault on AB kinetix 350 servo drive



## Breakfasteatre (Sep 8, 2009)

we are commisioning two AB servo motors with absolute encoders connected to kinetix 350 servo drives.

some back ground, when we attempted to first start up, we realized that the encoder cable terminations were incorrect due to using the wrong connector wire layout

when we corrected the wiring, we get a battery fault. 

battery is a 3.6v lithium cell. It meters out at 3.6v

integrator has bypassed battery check on startup, and the servos move and home, and upon power down, encoder position is maintained in memory, so it seems as if the battery is fine.



any thoughts? AB tech support had no ideas

i would replace the battery but it meters out fine, unless it needs like 3.69V and ours only measures out at 3.63v or something sensitive like that?


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## paulengr (Oct 8, 2017)

Don't trust AB batteries and battery indicators!!! They are all defective, every single one. Swap it out now and get used to doing it on a routine basis. Whether it says "good" or "bad". Lithium batteries tend to maintain their voltage much better than the other types but it's a trap. You really won't know until the battery actually fails. You can't just go by voltage on lithium batteries like you can with NiCd's and alkaline...it's like carbon-air. The only decent accurate test is a load test.

So I'd just replace it now and not get surprised later. Not sure about Kinetix but I've been buying batteries either via Batteries Plus (locally owned) or PLC Cables because they're cheap and have "everything" AB wise.

I can't tell you how many PLC memory lost failures or faulty good/no good indicators I've had to deal with over the years. Way too many. Just don't trust them.


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