Monday, June 13, 2016

BATTERY ANOMALY PART TWO: Readings and observations

 I looked to the cause of why Battery 4 of my 48 volt Electric Propulsion bank was not charging properly. Since the terminals for this battery can best be accessed by the starboard  locker hatch I first had to empty out the locker and then squeeze my large frame down into it.

Taking off the protective caps on the negative terminal I had quite a bit of corrosion on it.

 This was because I had become somewhat  complacent in checking and cleaning the terminals. Mostly because up to now the battery charging had been operating normally.  The failure of battery four just happened a few days ago. After cleaning the terminals I used an battery tester to check it:

The readings above show a voltage of 10.87 volts and an internal battery resistance reading of 196.2 milli ohms. Which is a much higher resistance reading than when I last checked it on February 12, 2012.Which was 2.43 milli ohms. So obviously something had changed in this battery.  I will try a few more attempts at charging but, I don't think things will approve much. TO BE CONTINUED.


svfugu said...

How many seasons have these batteries given you?
I must admit it'S annoying when something that big and heavy needs to be replaced, but overall, it's not a bad service life.

For ease of future maintenance, is it possible to wire up a remote testing station?
For example, to have 5 leads taken from each pole of the 4 battery string to a connector that is easily reached (like at the nav desk) which allows you to to periodic readings without having to access the terminal directly. Or, are the individual resistances of the lengths of wire to allow this playing too much of a role in the measurements?

At any rate, it's got me thinking about season 3 with my 16-cell lithium pack. So many connections...
Thanks for posting this!



Capt. Mike said...

Jason the battery bank has gone through eight seasons this will be the ninth coming up. Yes they have been holding up well. I actually do have a meter monitoring each battery as well as total pack voltage and current for the pack. I also have the ability to disconnect them and maybe do the tests at the helm position. I'll do a check and see if there is a big discrepancy doing it at the disconnect or directly on the lugs. It certainly would make testing a bit easier.