PL8

[shirley_hkg]

https://www.wheelchairdriver.com/board/ ... =2&t=11225


https://www.wheelchairdriver.com/board/ ... =2&t=11685 …Here BM is looking at another one https://www.pp-rc.de/CHARGING-TECHNIC/A ... =2345V&p=6


This is the still the best charger with the highest CP value. https://www.wheelchairdriver.com/board/ ... start=1680

[LROBBINS]

I suggest contacting shirley_hkg about getting a PL8 and a modified ZXD power supply to go with it. Shirley has done a great job of locating PL8s, used but tested and in good condition, and the ZXD is versatile and very solid.

[Burgerman]

Thas what I would do too. All the rest are not a known quantity andthe devil is in the details. And the PL8s are computer controlable, and once you see how essential that is you cant be without it. Get 2. Or 3. Then you need not worry. But also get 6 of the malance connectors from shirley too, as they are almost impossible to get.

Or get one of the better iChargers.

[Burgerman]

I have 4. Used for almost a decade. Can break mine. Including 2 converted to blutooth. You were unlucky. Expresso had one that let out the smoke too. But nothing is 100% reliable. But these are better than most. Thats why I said get 2. Or 3.

[Burgerman]

i have just over $300 left in my bank

Well there are no cheaper ways that are any good.
You could use a shirley ZXD and a BMS but thats not what I would do for a bunch of reasons.

[LROBBINS]

Have you used a volt meter to check the balance connector cell-by-cell? Could the odd voltages seen by the PL8 be a problem with the balance wiring? I use a DB9 for my balance connector and have made a short cable with DB9 at one end and a board with the 9 leads spread out at the other, so it's easy for me to check this any time I've mucked about with the physical setup.

[Burgerman]

Because you dont understand what the pl8 measures.

The multimeter reads the everage voltage.
The pl8 charges in high frequency pulses. So it reads voltage in several different ways. All are different and all are correct. For e.g itreads the true battery voltage, during the OFF times during the charge. This is happening at 3 different high frequencies. It also measures cell voltage and battery voltage during the ON time. This gives a higher cell reading, because of the cell internal resistance. And thats how it measures resistance. It also displays actual cell voltages, from one of these three readings, and an actual measured and averaged battery boltage. Which means that the sum of the cell voltages will not = the battery voltage either. On top of that it averages the group of cell voltages and makes a prettier graph, unless a cell is a fair bit out of Balance. You can enabe or disable this data averaging if you know how.

So you cant measure its accuracy or even get close by doing what you did. All a basic test meter can tell you is if the cells are all reading the same plus or minus say 5mv after the charger has fully balanced all cells fully, and you set the PL8 to monitor (not charge).

[shirley_hkg]

Over 20+ people here are using PL8 , and 10 of my friends locally use it too. None has failed, so it may not be a John's biased preference. A few do show incorrect voltage (≤10mv) with one or two balance pipelines due to a deteriorated resistor/capacitor over time.

Maybe we can help if you would let us know more about your PL8 was doing .

[Burgerman]

the PL8 was NOT in charge or discharge mode this what before even starting any cycle on the unit

It doesent read voltages unless charging or discharging.

And then, before you can get the PL8 to read any accurate voltages you MUST enable this 4 decimal place display, as shows below. It doesent just add another decimal place it removes the "neat graph" data averaging between high and low cells. And then you need to let us know what fluke you were using. Because you are measuring a square wave at high frequency. My fancy expensive fluke gives me FOUR correct but quite different voltages. It reads peak (at the top of the waveform) and low (at the bottom of the waveform) and average (between the two) and the instantanious measurement which is udated several times per second and is the true RMS figure. Tell me which one were you using?

Only the low one is correct and matches the fluke. My cheap fluke reads this waveform as a voltage that is wrong. How wrong depends on the amount of charging or discharging that is going on. The ONLY time the correct cell voltage will ever be displayed on the PL8 is if you choose monitor, and then measure with your test meter. AND tick the box below. Which also removes the data averaging that pulls the cells "closer" together. This is the ONLY way to make the PL8 display raw cell voltage data.

If you dont do this, MONITOR and Tick the box below, your readings are pointless. And do not show true voltage at all.

[Burgerman]

And here is what I mean about voltage reading.
This is my model fluke.
Notice that a meter that cannot do this, cannot read voltages from a pulsed square wave, or AC wavform. This is why theres is FOUR correct voltages. This is true on AC or DC measurements. All at once. The pl8 is digital, uses data averaging, and monitors many voltages at once. Like this fluke below. The meter runs at very high frequency. It can see the battery voltage, the peak (on charge pulse) voltage, the average between the two, and the true RMS instantanious voltage. All at once as you see it.

Tell me which voltage is the "correct" one below? They ALL are. The nature of measuring a DC voltage from AC waveform or a pulsed waveform. In the case of the PL8 its a pulsewidth waveform inside the charger, at high frequency. On/off squarewave, with breaks so it can read the low cell voltages. You cant just stick a "voltmeter" on it and understand what is going on.

This isnt to say your fluke isnt faulty. But you CANNOT test is in the way you did.

[Burgerman]

hmm so if you type the word G OD (with out the space) it changes it to "imaginary friend" ????

Yes it makes the correction for you.

[fishinjunky]

since my mobility scooter id down to a range of less than 1Km till i get my new cells and make then in to the 2 packs i have been stuck here for 4 + weeks and will be at lest a few more so i have been looking around and here are a few other possibility's to replace the PL8

what are your thoughts on them?

Some need a external power supply but that just makes them more versatile in there configuration

ToolkitRC M9 600W
CM1620 1100W 20A Lipo Battery Charger Charging Module for Rc Models 2-16S Life/LiPo/LiHv Battery ect
Q8 MAX DC 1000W Lipo Battery Charger,LCD Display Digital Smart Battery Balance Charger
Air8 Smart Lipo Charger,DC 500W 20A Balance Charger for 1-8S Lipo Batteries

I would not take a chance on those 3 chargers no one here has experience with them charging lifep04 they could work or they may not no one knows. I agree with everyone a used PL8 as a first choice. A second choice if your on a low budget would be a iCharger x8 and a 24v server psu all though not nearly as reliable as a ZXD psu. Im using a iCharger 4010 duo to charge my lifepo4 pack and a 24v server psu both are working fine ( but not enough of us using iChargers on lifepo4 packs to get an idea of reliability). I just wouldnt max out the iCharger x8

iCharger x8
https://www.progressiverc.com/products/icharger-x8

24v server psu (example)
https://www.ebay.com/itm/255994172704?h ... R_CSv-7WYQ

[fishinjunky]

Because you dont understand what the pl8 measures.

i am starting to see a pattern with you, you jump to conclusions to quickly and make assumptions about other people

the PL8 was NOT in charge or discharge mode this what before even starting any cycle on the unit

i have been using small lipo packs for over 10 years and hobby chargers for the same length of time i just havent delt with lifepo4 cells but i do know how to use and read a balance charger

i asked for others to look at the charges i listed and all i got was dont be stupid buy 10 of these ones i use
not i have looked at them and
<item name> looks <add opinion here>
<item name> looks <add opinion here>
<item name> g o d dont touch it

BM is just trying to help save you more heartache down the road

[Burgerman]

Correct.
I have used dozenz of hobby chargers, good, bad (most of them) and cheap, expensive and everything in between. I have been a consultant, for 3 manufacturers, including (unreliable) hyperions, and advised and worked with and against revolectrix to get that one working properly for our needs. That alone took 5 or 6 different firmwares, 6 yeaars of emails and hundreds of posts. I also have been using hobby chargers for 45 years! And selling various battery types commercially. I know whats needed, I understand all the problems, I know what we require. 99% of chargrs do not offer that.

Of course anything might work. To a degree. Try using a potato to charge. You can also use a diode, and resistor to get DC and limited current direct from the wall. That will charge too. Practically anything will charge! Just not properly, safely, or in a way that is good for the battery. You want to ruin your battery which is expensive by using a cheap charger. Makes no sense to me. But its your money.

[Burgerman]

The problem with those is that they never had PC control/graphing or info software and they did not have the same firmware mods that I managed to get changed on the PL8 over 6 years of working with their engineer/firmware testers. So it worked well for big LiFePO4 or lead packs properly. So I cant help. Will it charge LiFePO4? Yes sort of... You may get unexpected errors, timeouts, unstable balancing, and a bunch of charge voltage errors etc though. Thats what the PL8 did originally untill I got them to fix... They didnt fix the rest of the chargers only the PL8. As far as I know.
It did have a firmware flashing utility but no idea where you would get that or the firmware now.

The same with lead. Even their newest firmware will still do all the stuff the PL8 used to do.

[shirley_hkg]

Sell it on ebay. People are still going after it.