Pulsar EQUALizer from Elprog
It has been about two months since Elprog EQUALizer hit the market in Europe. Due to the disappointing US$ exchange this information is of little use for most of us, but European owners of PULSAR 2 would look at a PulsarEQUALizer as a practical alternative to make Pulsar 2, with all its bells and whistles, shine again among the current breeds of modern chargers.
I have been experimenting with this "duet" for a couple of weeks now and let me tell you, this thing is a blast. As some of you know Pulsar 2 is a powerful serial pulsing charger/discharger capable of delivering 250W up to 60V. The 12 cell capability of their new EQUALizer brings the usable 50V LiPo packs into the ballpark of a 5A charge and with packs of 12 A123 cells it is usually done in less than 20 minutes, perfectly balanced. Field results show that the Pulsar combo is a lot faster than Shultze NG units. Packs charged on a PULSAR are predominantly well balanced right of the charger due to intensive balancing during the charging process.
To describe this duet shortly:
-Powerful combination of single output charger/discharger (250W/250W - still in the league) with state of the art balancer (45W/750mA discharging capability).
-FAST charging and FAST balancing processing algorithms included
-extremely energy efficient ( both charger and balancer) in all modes
-widely adjustable (both charger and balancer)
-PC interface for both charger and balancer. If you have two serial outlets on your PC you can monitor EQUALizing and the charge progress at same time on two separate windows
-EQUALizer is the only independent balancer with its own PC interface and software
-EQUALizer data cycle is synchronized with the pulsing characteristic of PULSAR 2. This unique quality allows EQUALizer to measure cells at resting Voltages staying away from wiring and cell noise dynamics associated with high current charging.
-PC upgradable software for EQUALizer
How the Pulsars EQUALizer works:
The First and foremost:
EQUALizer is a discharge/charge type of balancer, not a bleeder. It will charge lower cells to the expense of higher ones.
As long as a balancer is part of the balancing charger this is not a big deal, for an independent balancer it is not something seen too often and shows how designers were obsessed with low energy losses. EQUALizer is powered from a balanced pack. It is essential to keep the energy consumption low. As you might expect, the back light on the LCD screen is not operational for that very reason.
Power applied in charging lower cells is in accordance to how far off they are against the average V value. These values are calculated between 0-100% in 9(10%) steps. It means that the cell nearest to the average Voltage will receive no charge or just 10% of the established maximum current (user definable in the 250mA, 500mA or 750mA range). It also means that, if the cell voltages are close to each other, the current will no longer flow to these cells or will flow at 10% of the defined "I" value for any cell falling behind more then 3mV. You could call it "soft finish" balancing. Thanks to this "variable current intensity" the balancing process is very radical at first and soft at the end with little energy loss.
Balancer diagnoses cell voltages at the resting stage between charging pulses from the Pulsar 2 charger.
This specific characteristic of slow pulse charging does wonders in regards to correct Voltage readings and helps balancing remain clear from the dynamics of wiring and cell resistance noise encountered with high current charging.
The Balancer does not operate at all times.
In FAST (coarse) mode, the balancer goes ON if the difference of 25mV is spotted and goes OFF if all the cells are parked within 12mV of the average value
In EQUAL (fine) mode, tolerance is narrowed from 10mV to 3mV. Balancer works on more cells with a wider power level distribution with very fine 25mV topping, if desired
Additionally, balancing does not occur below a certain Voltage level. It depends on the battery type (look at the chart in the manual)
In extreme cases, the balancer will go ON if there is approximately a 0.45V difference to rescue the first cell to fall behind.
Hefty (750mA) balancing impulse has an authority. All the power goes there.
EQUAL operates in three modes:
The balancer continuously monitors cell voltage without balancing them.
Safety disconnect and a balancer moderated charging current is still active
This mode is used to monitor the behavior of the cells during real load in the model
This is also an opportunity to watch how the charger alone handles discharge and charging process in real time.
In previous threads about the PULSAR 2 I was positive in using a reflex charging algorithm to let the cells self balance.
Monitoring this process through the EQUALizer proves this to be true.
-FAST mode (coarse)
Intended to be used with FAST (CC) charging mode of PULSAR, allowing it to balance with higher Current(I) rates without fear.
With a threshold of 25mV-10mV power applied to the cells has a different pattern then STD(EQUAL) mode and it does wonders
I am still investigating this mode
-EQUAL mode (fine)
The standard mode where all cells are under supervision between 12mV(ON)-3mV(OFF).
Again, max current is user definable and value can be applied in relation to the size of the battery pack
I am not an expert or professional in this field.
I am inviting all the experts and owners of ELPROG products to comment.
The complexity and smarts of their products are far from ordinary.
( No! CORO.... PULSAR is not what you are trying to compare it with... look at it closely ... and be an expert)
Unfortunately PULSARs are not made in China so they are on the expensive side, fortunately, though, they live long reliable lives.
Shultze... or Pulsar?
For a regular user like me a 6 page manual is plenty to get me confused
Smart simplicity is often a blessing
After more than 2 years of intensive use, PULSAR is still able to pleasantly impress me.
Now with EQUALizer on hand it shows what these guys have been thinking of for the last couple of years
Maybe this set is not as ordinary as it might look.
For reference links check my web site: LittleSoaringFleet
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Last edited by Smyk; Apr 15, 2008 at 12:31 AM.
Of course it was a balancing there
.75A is nothing against 6A charging
It was a pack straight from Dewalt container and some of the cell were realy behind.
Without balancing power the red cell would never go up to meet the rest of the pack. When the highest cell hit the 3.7V mark balancer has reduced the current couple of times for a next couple of minutes allowing the balancing boost to be more and more effective.
As you can see it did not take long to bring them in the ballpark of 25mV
Bar display shows time about 17 minutes and you can see the power is there
Red cell gets 100% at 750mA.
It seems like in FAST mode only lowest cells are charged
in Equal mode all needed take a proper share - the other end ( 57th minute)
Last edited by Smyk; Apr 14, 2008 at 11:28 PM.
I think I understand now
You do not see that little shark teeth on graph like in the case of Li-Ion
A123 have a such low internal resistance that extra 750mA impuls would not change a momentary voltage at all, while Li-Ion cells will respond noticable.
By the way big inpulses are from pulsing charger
balancing charge is hardly noticable and need close zooming on the graph to be noticed.
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Last edited by Smyk; Apr 15, 2008 at 11:46 PM.
This is well broken in and reliable unit being on the market in Europe for couple of years now. It does 12S1P A123pack in 22 minutes completely balanced
The thing is it goes along with new balancer with no issues spotted.
All of the confusion regarding the balancer is its complexity and concept philosophy not falling into common stereotype what balancing is all about.
We do not know what discharging current values are. We know that max charging current is 0.75A per cell. EQUALizer charges the lower cells in expense of higher cells. If it charges one cell at.0.75A it must discharge the other at 0.75A. Over all capability must be at least 2 X 0.75A at the same time.
Balancing power is at 45W level. Find me any other balancer at this value
If considering 225W average power doing 12S1P of A123 pack ( It depends how good the supply battery is) 45W balancing power falls in 1/5 (20%) range of Pulsars charging capability (250W)
10mV on LCD screen
1mV on the computer graphing
12mV - 3mV on EQUAL mode
balancer goes ON if 12mV difference is spotted
and goes OFF if cells fall in 3mV range and waits until 12mV delta builds up
Because clock on the PC graph is different then measuring timer you can see balancer goes ON and OFF while graph values oscillate between 5mV and 10mV
In FAST mode (coarse) threshld is between 25mV and 10mV with more radical balancing power distribution toward lower cells
Check the above graph again
you can see at 59 minute time frame rapidly narrowing balancing values from 25mV to 10mV in the matter of 1 minute
I have just switched from FAST balancing to fine EQUAL balancing mode
Additionally if you connect balancer in series with a charger (any charger) it will trigger emergency shut off in case one of the cells goes too high.
However to take full advantage of efficiency, precision and time devoted to charge large batteries packs use of the PULSAR 2 is essential.
Elprog Equalizer works also with Accumatic chargers in the a same manner like it does with Pulsar (triggering CV phase), but Pulsar 2 offers such interesting charging algorithms. This makes balancing jobs not only easier but also reduces the time of CV phase and post charging balancing is almost reduced to zero.
This is an area where Pulsar dominates performance of Shultze NG charger.
Time devoted to charge large battery packs has many flavors and is not only End Power of the charger responsible for it
If you use bleeding balancer which takes 20% capacity you are 20% of your time behind + waste of the energy
if you come to the end of the CC phase with highly unbalanced pack CV phase is taking forever to even them up + risk that pack might become shut off too early reducing over all charged capacity. Even though balancer is still at work End Voltage might end up much lower then we expected reducing capacity of the pack as well.
Pulsar Duo cleverly balances the pack on the initial slope going up hill of Voltage curve giving a chance to reach CV phase at average higher and more equalized Voltage level consequently shortening the rest of the CV phase to the minimum (big time saving) and have a balancer have some authority to finnish the job. Because EQUALizer is a charging balancer there is NO time or energy lost
I hope everyone likes these ideas
I forgot to mention that FAST(coarse) balancing is another feature to keep the cells in ballpark of 25mV during the charging process
It comes in EQUALizer features it means it would work with any charger
Goal is to keep more outer cells closer with median ones and keep the whole pack away from early termination especially due to one cell being too high or one lugging way behind and let the balancer to work forever on CV mode.
Observing the pack on the computer is another great learning experience what is your pack capable of. There is lots tricky and bad cell among A123 samples. I am poised to report some of my findings shortly.
Bad numbers can indicate a troubles , but pictures and graphs usually can give you a chance to have a clues why.
I believe the EQUALizer and PULSAR to be very sophisticated and powerful tools for maintaining batteries and appreciate your detailed description of their operation.
I am also acutely interested in your findings from analyzing the charge and discharge graphs of various LiFePO4 cells - please keep me/us posted and I look forward to your results.
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