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Re: (ET) HL-Controller vs The E-meter
Jim, your calculations are good on
paper but in real life when I use the tractor starting with a Full
battery I can run for about 2 hours. This brings the battery down
to about 80% DOD. With the Landis controller in the charger,
plugged in all day and night when I start using the tractor the next day
I can only run for about 20 minuets before the tractor slows WAY down
from weak batteries. The E Meter confirms this
"Battery at 0%" condition. You are correct that the E
Meter is difficult to program. It takes me several tried to get is
set to the tractor.
R.
>
I think that the E-meter and the Harry Landis Controller may be
mutually
>exclusive (I say never having tried it).
>
>The e-meter has a lot of great features but all the
programmable
>parameters can make it tricky to use. So bear with me for a
longish
>explanation...
>
>When the tractor is in use, the e-meter counts actual Amp-hours
used
>(although the % remaining 'fuel' gauge is corrected based on
Puekert
>number, but that is another story). So far, so good.
>
>When the tractor is charging, the e-meter shows *corrected*
amp-hours
>put back into the pack. This correction is based on the
"Charging
>Efficiency" (CEF) that the e-meter calculates based on past charge
>cycles. For instance, if the CEF is 90% then when 10 actual amp-hours
>are returned, the e-meter will show that 9 amp-hours have gone in. I
>won't tell you how many years of using an e-meter it took for this
>detail to penetrate my skull.
>
>The CEF is recalculated with each complete charge cycle. A complete
>cycle (or "reset to zero") requires 5 conditions to be met:
>1) At least 10% of the batteries capacity must be used (so very shallow
>discharges don't count)
>2) 100% of the KWhrs removed must be returned by the charger
>3) The pack voltage must rise above the 'charge voltage' parameter (say
>40 volts)
>4) The current must fall below the 'charge current' parameter (say 4.4 amps)
>5) Conditions 3 & 4 must be met for ***at least 5 minutes***.
>
>With a standard battery charger, the charge cycle starts off with a high
>current (say 20 amps) and the pack voltage starts slowly rising as the
>battery charges. As the bulk of the charge gets done, the voltage rises
>more quickly as the current falls quickly. If the charge parameters on
>the e-meter are correctly set, the meter sees a complete cycle and is
>happy. Out of the box, the e-meter starts with a CEF of 90% and then
>updates this value each cycle as it learns about the particular battery
>pack.
>
>If the charger keeps going after the e-meter sees it as full, positive
>amp-hours are accumulated, but as soon as you start driving/mowing it
>jumps back to zero and starts counting negative as it should.
>
>Now add a Landis controller to the charger. As I understand it, the
>charger no longer runs continuously until done, but rather cycles on and
>off. On an empty battery the off time is short, and becomes longer as
>the battery reaches full charge. So now even when all the KWhrs have
>been returned to the battery pack, the 5 conditions for a reset may not
>be met - particularly #5 that requires the conditions to hold for at
>least 5 minutes.
>
>The result may be that the e-meter never sees a "complete" charge
>cycle, so it doesn't reset to zero properly and it doesn't recalculate
>the CEF. Or worse yet it occasionally does see a reset after sitting on
>the charger for days and ends up calculating a horrible charge efficiency.
>
>Some options to get the e-meter to reset to zero on complete cycles
>might be:
>
>- Make sure the 'charged voltage' is below the final voltage of the
>charger & HLC combo; make sure the battery capacity is set correctly
>
>- Increase the 'charged current' parameter from say 2% to 4% of the pack
>capacity, so the charge current doesn't have to fall off as far
>
>- Change the time to meet the charged parameters from 5 minutes to 1
>minute (F05)
>
>- Manually set the CEF (F06) - "not recommended" per the instruction manual
>
>Could also set the e-meter to count KWHrs in/out, which are not
>corrected in any way (F04) and use the human brain instead of the
>e-meter brain to track things.
>
>I'll be curious to hear the results of any experiments.
>
>
>oleoranch aaahawk com wrote:
> > I have several "Landis controllers" and I had one on a tractor
> > with an E Meter. The E Meter keeps track of all battery functions
> > including ah out and back in. With the Landis controller the
> > charger was never able to replace all the ah I has used. Even
> > if I let the tractor sit plug in for 2 weeks. The Landis controller
> > is fine for maintaining full batteries for long periods of sitting
> > but will never fully recharge the batteries if you use the tractor
> > on a regular basis.
> > R.
>
>_________
>Jim Coate
>1992 Chevy S10
>1970's Elec-Trak
>
>
>
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>Elec-trak cosmos phy tufts edu
>
- No trees were destroyed in the creation of this E Mail, however many
electrons were severely inconvenienced! RAV
(DofTI)