Re: (ET) The battery hunt (was: mounting a rotarty invertor?)

["Markus" <ev lorch net>]

Hi Kelly,

given your alternatives I would suggest the following

the 6V batts for $45 each seem to expensive, two years
ago Sam's Club had new 6V batteries at about $50, dunno 
the price today but would guess around 55-60. If you go for
6V batts then I would go for new ones given the alternative.
This will also let you use the built in charger and you have
ample capacity. With the 0.6 acre use they should last many
years.

Given my experience with the 12V SLA 100Ah (which were also 
used UPS batts) and the relatively small 0.6 acre lawn
I would argue that they are about sufficient. (If not you
give them an overnight charge). 
 
If you are not sure that the batts are all same age/ same
condition I would be very careful to stop mowing BEFORE 
the battery meter goes into the red as there is a good 
chance that one of them is fully discharged and you risk
a cell reversal. I'd go as low as 10.5V per batt, not lower.
I had "finished off" the yard a few times with low batteries
and killed one of my SLAs (I had a backup) due to extreme
discharging. Definitely DO NOT go with the build in or any
other 36V chargers if you have old/unequal batteries. Do not
use the built in charger for SLAs other than for a brief
charge to bring them up to 14V or so. (They gass as 14.5V and
that water can't be replenished)

The 3 12V Soneil/ACC chargers (they are exactly the same, see
my old posts in the archive) are good. I had the same ones and
I used them to do many tasks, including charge my car and
kids toys 12V batteries etc. They will charge the battery over
night and keep them on a float charge if you forget to unplug.
They are also pretty efficient compared to the built in charger.
(I recommend to unplug them after a day or so, also I recommend
to adjust the finish charge voltage of these chargers as the 14.7V
to which they charge is too much for the large UPS SLA. I have
instructions from Soneil on how to do it that will not void
the warranty (I had confirmed that with battery mart when I bought
mine several years ago)


So for you its $360-400 for new 6V, using the built in charger
 -> advantage, long range, long live, easy charging 
    (no fuzz with many chargers, wires)
 -> disadvantage, higher cost, acid mess & fumes  
or $200 for 3 12V SLA plus 3 chargers.  
 -> advantage, is lower cost, not acid mess, 
    double use of chargers for other purposes
 -> disadvantage, the batteries will prob. be "just sufficient" 
    which means you are fully using them and may have to get another
    set in new ones in 2 years or so, also you have to always
    hook up and plug in 3 chargers (unless you mount them on the
    tractor, but then there is no double use :)
 
My decision would be:
Use the SLAs to start with and "play" with your tractor plus learn 
how to take care of batts. (everybody ruins their first pack). Keep
looking for good, used 6Vs. 

hope this helps
Markus

> OK, here's the latest.  I can get some used returns
> for $40 each, only 4 instead of 6 unless I lean on the
> battery place.  I can get a set of seconds (probably
> Exide GC110) for $45 each.  I can get new GC110s for
> $71.50 each.
> 
> BUT - I can also get 3 used "UPS batteries", 12v, 13"
> wide but not as tall, for $25 each.  (I forgot to ask
> about capacity.)  SLA, VRLA, the guy says .  I'm sure
> I'll have to change my cable ends (or make cheesy
> adaptors using top-to-side terminal converters :-),
> but 3 of these plus 3 of the Soneil 1206's, or the
> version at
> http://www.batterymart.com/battery.mv?p=ACC-1206WB ,
> would still let me get away for less than a set of 6V
> seconds.
> 
> More thoughts?  What might the 12V SLA's be like in an
> E12M that wants to mow about 0.6 acre on a slight
> slope?
> 
> Kelly Williams
> Mount Joy, PA
> 
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