PL8 settings for headway charging

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PL8 settings for headway charging

Postby headrc » 07 Aug 2018, 03:53

I am following your lead here folks and have purchased headway cells to build a 24 volt 8s3p with 20ah headway cells. Before I build the pack with balance leads I want to charge the cells to the proper top voltage of 3.6V. I understand that is what they should be charged to. I also bought a PL8 on the recommendations here. Can someone please give me a setting for the PL8 for the individual cells ....and then if it would be different (other than more cells and balancing function) for the pack when built I would appreciate a setting that too. I know this has been gone over all over the place here but I could not find one thread that just gave the basics. And since you have sussed out the proper settings I thpught I owuld just ask here. Thanks ...you guys are the power users in my opinion. RH
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Re: PL8 settings for headway charging

Postby Burgerman » 07 Aug 2018, 04:18

I didnt know there were 20Ah headway cells?
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Re: PL8 settings for headway charging

Postby Burgerman » 07 Aug 2018, 04:36

So 60Ah?

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LiFe PO4 60Ah 24V 8S 300thC T.PS8.ZIP
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LiFe Charge ONE 10 to 20Ah Cell.PS8.ZIP
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Re: PL8 settings for headway charging

Postby headrc » 07 Aug 2018, 04:44

Yes 60ah ..I am using it for a rc controlled tool carrier for mowers, weedeaters etc. And yes Headway now has 20ah cells .. purchased off alibaba from Headway direct I believe. Here is a link to them. https://www.alibaba.com/product-detail/ ... 2fc2C7X7DM .
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Re: PL8 settings for headway charging

Postby headrc » 07 Aug 2018, 04:52

And TY for those presets ....I find the PL8 not as straight forward as the previously used Hyperion. Meaning I could not find a straight up LifePo4 setting that I could modify. So this helps .... although I still don't see where you choose a particular's cells chemistry ...yet .... but I will keep studying.
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Re: PL8 settings for headway charging

Postby headrc » 07 Aug 2018, 04:56

I just loaded those presets too ...is that 8s balancing setting at 3.5v mean the cells must be a 3.5 to balance? Can you explain this please. No BMS is involved. Thanks Burgerman ...I will do my best not to bother you too much on this. Hopefully that info on the 20ah headway was of interest....RH
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Re: PL8 settings for headway charging

Postby biscuit » 07 Aug 2018, 09:06

Maybe those aren't lithium iron phosphate cells? it just says lithium ion on the spec. So then the chemistry might not be good for wheelchairs.
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Re: PL8 settings for headway charging

Postby Burgerman » 07 Aug 2018, 09:52

They look like 10Ah lithium ion phosphate Headway cells, just two in parallel. To give 20Ah.

How many blue cells do you have in total?
For 60Ah you must have 8 groups x 6 cells = 48 total blue cells.

Why balance at 3.5V? Thats the point where it begins balancing. It continues to do so at CV. You cannot balance Lithium ion Phosphate cells at a lower voltage as this puts them OUT of balance. State of charge below this point is not the same as voltage. And can even be reversed. Many BMS do this all day long!!!

There is no suitable existing preset to modify that will work properly. There are half a dozen changes behind the scenes that are not user adjustable in my presets. So if you really want to make your own, use mine as a starting point. Same for lead...
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Re: PL8 settings for headway charging

Postby LROBBINS » 07 Aug 2018, 10:15

Product listing details show those cells as cylindrical, D43 x H184 whereas the 10 AHr cells are D38 x H120.
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Re: PL8 settings for headway charging

Postby biscuit » 07 Aug 2018, 10:31

Is the cell voltage of 3.2V the guide to tell if it's LiFePO4? Some other ions seem to be 3.7V. But what those are, idk. TNT maybe, or some other chemical soup in one half of the battery.
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Re: PL8 settings for headway charging

Postby woodygb » 07 Aug 2018, 11:45

http://www.cobox-ebikes.com/296/basic-u ... fepo4.html

Note that B.M. may disagree on some of the technical aspects ...but this link should hopefully give you an understanding of the various chemistry's involved.
An expert is a person who has made all the mistakes that can be made in a very narrow field.
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Re: PL8 settings for headway charging

Postby headrc » 07 Aug 2018, 16:24

So ...I made a mistake on getting these cells then ? They are not LifePo4? The listing definitely states they are LifePo4 but then I see the spec states Lion and the max charge voltage states 3.65. If they were Lion would that not be 4.2?
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Re: PL8 settings for headway charging

Postby Burgerman » 07 Aug 2018, 16:41

They are headway cells. You bought 10Ah headway Lithium Ion Phosphate -- LiFePO4 cells. Eacth 20Ah you bought got you 10Ah x 2.
These.
http://www.evassemble.com/index.php?mai ... 0vu8e01jq1

So as I asked. HOW MANY CELLS do you have total?
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Re: PL8 settings for headway charging

Postby headrc » 07 Aug 2018, 18:53

I have 24 of them ...and I am now wondering if they will do the job for me. I screwed up and did not review the C rate upon purchase. They don't have the same C rate as the ones you are using.
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Re: PL8 settings for headway charging

Postby Burgerman » 07 Aug 2018, 19:51

So you only have a 30Ah battery? Is this an addon pack?
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Re: PL8 settings for headway charging

Postby LROBBINS » 07 Aug 2018, 19:53

John,

Did you see my post above? From the listing details it appears that these are single, larger cells not pairs of 10 AHr cells.
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Re: PL8 settings for headway charging

Postby LROBBINS » 07 Aug 2018, 19:55

Biscuit,

3.65 is the maximum charging voltage (and you should almost surely use lower than that). Charging voltage has to be higher than nominal cell voltage or you can't pump anything back in. A 3.2V LiFePO4 Headway will indeed have a maximum charge voltage of 3.65V.
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Re: PL8 settings for headway charging

Postby Burgerman » 07 Aug 2018, 20:04

No I didnt. Hovever, the:

Product listing details show those cells as cylindrical, D43 x H184 whereas the 10 AHr cells are D38 x H120.Product listing details show those cells as cylindrical, D43 x H184 whereas the 10 AHr cells are D38 x H120.


Orange blocks are 40mm or 41 if the interlocking tabs are included... As per the photos on that site?
And the length of 120 is without screws, washers, bus bar, eack end, or the orange blocks with the 4 spacer pins that allow safe clearance of the screws/bus bars etc. So its likely that the extra length measurement is wrong, and is actually the 150mm of the 10Ah cell complete. (170 for the 12Ah).

So without info confusion remains!
A decent photo and a few measurements would help clarify?
No site I frequent mention any 20Ah headways. 8Ah 20C high rate, 10Ah 10C same physical size. And the 10C 12Ah, 15Ah, and 16Ah updated ones are all that I see.

In china anything is possible. Incorrect figures, incorrect capacities, and incorrect C rate. Plain lies to sell, relabeled used batteries. And new limited run products intended for a specific purpose, batches of strange cells, clones, copies, back door rebranded, so its anybodies guess!
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Re: PL8 settings for headway charging

Postby steves1977uk » 07 Aug 2018, 20:22

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Re: PL8 settings for headway charging

Postby Burgerman » 07 Aug 2018, 20:59

Those have been around for a bit. Intended for solar storage etc as they are quite low rate.
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Re: PL8 settings for headway charging

Postby headrc » 08 Aug 2018, 01:58

24 of these should give me a 60AH battery if the 20AH rating is correct. They may not be the C rate because of my mistake but they are 20ah batteries. Unless I really misunderstood this as well. I can take a photo and measurements tomorrow if this will help.
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Re: PL8 settings for headway charging

Postby Burgerman » 08 Aug 2018, 02:02

Yes. But I cant find a headway 20A one without seeing 2 cells. So I am a bit confused. I THINK but may be wrong, that they are adding the two cells Ah together. Basically dodgy marketing. Also non shown on the headway corp site. So not really sure what you have there.
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Re: PL8 settings for headway charging

Postby headrc » 08 Aug 2018, 02:08

Me either now as far as knowing what I have. I appreciate all your input in trying to figure this out. I have another questions for you regarding charging these. I did use your preset to do that today on a couple of these cells and after reaching the 3.6 volts and end of charge the cells did not hold that voltage. They drifted down to about 3.45 volts and then seemed to hold that voltage. Would this be normal with Headway Lifepo4 cells too? If not looks like I am about to see how good Alibaba's trade assurance really is. Ahhh ...the lessons of life.
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Re: PL8 settings for headway charging

Postby Burgerman » 08 Aug 2018, 02:35

Thats normal for all LiFePO4 cells. If you were to set a low CV termination point they will float down more slowly. But that takes a lot of time. And many of us are charging 70 or 80 cells! So the single cell preset you have is set to terminate CV quickly.
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Re: PL8 settings for headway charging

Postby shirley_hkg » 08 Aug 2018, 02:36

It's normal . Cell won't stay @3.6V , and will go as low as 3.33x V after charge .
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Re: PL8 settings for headway charging

Postby headrc » 08 Aug 2018, 04:24

Ok thanks, I am used to Lithium Ion cells that don't drift down that much right after a charge. I just wanted to make sure before I went ahead an built a pack to see how it performed in my situation ...although I am feeling a little pessimistic on this due to be own shortsightedness. I have corresponded with the seller about the AH rating and one comfort factor is she responded fast and said she was going to communicate with engineering to see what is up. So so far, good customer service response and I believe I am doing business with Headway itself. Her email address is at Headway.com ...but who knows in this crazy world nowadays.

Burgerman, do you have a patch for the PL8 that could check the actual capacity of these cells with the specs they are advertised with? If not I can figure one out although again the PL8 is new to me. Do you use A123 patches for LifePo4 and modify?

I will keep posting here with updates on what happens. Thanks everyone for helping.
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Re: PL8 settings for headway charging

Postby Burgerman » 08 Aug 2018, 11:22

Burgerman, do you have a patch for the PL8 that could check the actual capacity of these cells with the specs they are advertised with? If not I can figure one out although again the PL8 is new to me. Do you use A123 patches for LifePo4 and modify?


Patch? Preset?

A123 no. I use my own presets, made from modified LiFePO4 presets. A123 ones are hopeless. But mine have many fields that you do not have access to or see. I modified them internally changing those that will cause problems with our packs. Such as allowing higher or lower cell voltages during the first few mins, and removing the stupid safety charge .5A thingy that kicks in if the cell differences exceed 150mV and a bunch of other stuff. So if you want to charge either A123 or LiFePO4 you are better to modify my presets as posted on here.

Yes the PRESETS that I posted will already measure Ah down to a safe level.
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Re: PL8 settings for headway charging

Postby headrc » 09 Aug 2018, 02:54

Thank you ...you really know the PL8. An update on my little situation, the seller has stated speaking with the engineers. They want an outline of what I am testing with and the testing parameters ...and then the results of course. I am going to do a charge/discharge test using your presets and see what I get for a capacity test. Any suggestions on that would be appreciated. I have not really checked capacity yet, just charging. Thanks, Richard
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Re: PL8 settings for headway charging

Postby Burgerman » 09 Aug 2018, 06:15

the seller has stated speaking with the engineers.


What seller? engineers?

Dont you think that the first thing you need to do is ask them exactly what you bought? Is it 2x 20Ah cells? Or 1x 20Ah being 10Ah each? Claimed C rating etc? As it stands we dont know what you have. And as such cant properly set up a charge or discharge for them.
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Re: PL8 settings for headway charging

Postby Burgerman » 09 Aug 2018, 06:37

Also, if you charge at 3.650V and then discharge to 2.500v then thats very extreme. Its what they will expect to measure full capacity, but its not what I would want to do to any of the cells I was going to use. If building a pack I usually get an extra cell. And do a test on the extra one I dont use.

So we charge at a slightly lower accurate 3.600V initially, and in service 3.550V to 300thC as it hurts the cell less and they will live a longer life. Likewise discharge to 2.500V wil be more than is healthy and can increase the natural self discharge level. And int resistance. So we discharge generally to approx 2.900V if a row rate discharge and 2.700V if at a slightly higher rate. The result of that is that you may see for e.g. 11.3Ah from a 12Ah cell.
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