Thursday, October 08, 2009

TLC for the batteries

TLC for the batteriesJust before I installed my new inverter/charger, I serviced the batteries. Giving the tops a good clean and topping up the cells with the right amount of distilled water.

I know I should do this at regular intervals, but have not really got around to drawing up any kind of schedule for that kind of thing.

Anyway, I immediately see that the batteries are holding their charge so much better as a direct result of the proper charge cycle delivered by the inverter charger.

The now redundant charger, which you can see in the foreground, never delivered the amps the inverter charger delivers. Consequently I'm sure the batteries ended up not being charged as they should have been.

The new charging regime has an 'absorption' phase, where 50/60 odd amps are poured into the battery at the start of the cycle. This has the acid inside the battery bubbling away furiously, giving the contents a good old stirring up in the process. I gather this helps eliminate the stratification of the acid and water in the batteries.

This seemingly quite aggressive charging seems to be good for the batteries, whereas there's me thinking I was being kind to them these past years, only applying relatively low amperage charges.

More learning...

11 comments:

  1. Hows the decalcifyer system going? are you still using it? did it work?

    ReplyDelete
  2. Anonymous4:54 PM

    De-sulphate, I think. And if your batteries seem more lively and able to hold a charge, my bet is that it is due to the success of the desulphating gizmo.

    The charge phases are usually "Bulk" which is the high amperage phase, "Absorption" which is less amps for a longer period, "Float" or "Trickle" which is a maintenance charge and "Equalization" which is a short over-voltage charge meant to even out the charge level in the various cells. Equalization would be a periodic maintenance activity.

    ReplyDelete
  3. Hi Rob

    Anonymous is right - de-sulphate.

    Regards

    Tim

    ReplyDelete
  4. Hi Anonymous

    Hmm, I should have written that post a little clearer I guess.

    On my charger, as per the standard configuration, the bulk charge brings the voltage up to 28.8 volts (high amps).

    The Absorption keeps this voltage at 28.8 using high amps until the amps drop off to < 10 or 2 hrs have passed. This is the high amps I was referring to.

    The Maintenance charge reduces the voltage to 27.2 V, and keeps this indefinitely while the generator is running.

    I can set the charger to periodically step the voltage back up to absorption, to de-stratify the acid and water, and can also set it to do the equalisation thing.

    I've not got my head around the equalisation bit, so have not tried anything in that department yet. My thinking being I'd rather not until I know what I'm doing.

    So fas as the batteries holding their charge better goes, I've been seeing a very slow but steady improvement in the voltage being maintained.

    The device only works when the battery voltage is above 25.6V, so does not work all the time of course. There is no doubt though that the gizmo has been doing it's job.

    Anyone who has spent time on board can tell you I track the battery voltages regularly.

    What I saw with the new charging system was a noticeable step change of about 0.2 volts, which on my 920ah battery bank is a significant jump.

    The new charging regime can be the only reason for this step change.

    Regards

    Tim

    ReplyDelete
  5. Anonymous9:08 PM

    Something you may want to keep in mind now that you have a high current charger is that when the flooded cells gas out, you are creating (1) a fine mist of sulphuric acid, and (2) an explosive mixture of H and O. Having these things regularly happen 50 cm below your expensive electrics is a sub-optimal arrangement. I would recommend a long range plan to put ventilated cabinet around the batteries to keep the nasties away from the expensive electrical thingumies.

    ReplyDelete
  6. I don't know much about batteries except that yes, they do need regular TLC

    ReplyDelete
  7. Hi Anonymous

    Thanks for that.

    Yes, the batteries already have a cover which goes over them for just that reason.

    You can see the unfinished version here: http://www.flickr.com/photos/timzim/3525219368/ The finished version has a fiddle (lip) all the way round it, and is painted up for beauty's sake.

    This also stops metal things, such as wrenches etc. being dropped across the terminals:)

    Regards

    Tim

    ReplyDelete
  8. This comment has been removed by the author.

    ReplyDelete
  9. Hi Valley P

    When I get roundtoit I'll make a proper schedule.

    It may be interesting for other folk as well.

    Regards

    Tim

    ReplyDelete
  10. My mistake, I was thinking about the use of calcium sulphate in batteries as mentioned in
    http://books.google.com/books?id=5Rwryml3YMEC&pg=PA127&lpg=PA127&dq=calcium+sulphate+in+batteries&source=bl&ots=kKE9BqEkzL&sig=gKRiL_QtfxsdV3cf9RWjPPTFito&hl=en&ei=svHOSun3M8OO_AaS2aDZAg&sa=X&oi=book_result&ct=result&resnum=1&ved=0CAsQ6AEwAA.
    My mistake once again for which I apologise! :o((

    ReplyDelete
  11. Hi Rob

    I feel a post coming on in response to this, as the reply got a bit long...

    Cheers

    Tim

    ReplyDelete