PL8 settings for headway charging

[headrc]

The seller is the one I sent you a link to. Same company name as is on the Headway site. And I did ask about what I bought and they tell me they are 20ah individual cells. Unless the woman I am dealing with there is confused ...but again the spec is 20ah individual cell ...not for two cells. Open issue though is is someone giving the wrong spec information. That is why I want to do a capacity test and send the results to her.

And I agree with you about discharging to 2.5V ....I think what I will do is to discharge to 2.9V and give those results and see what the response is.

[headrc]

Here is my update on these cells. According to a discharge capacity test using a patch from Burgerman these cells are 20AH cells and meet the manufacturer spec. Here are graphs from the capacity/discharge test I did and then the charge test that I did:

[Burgerman]

Looks good for the cells. If thats 1 cell. rather than a pair.

I wouldnt send that set of graphs though. Looks very odd. Like your PC or USB port went to sleep twice during charge. Leaving 2 huge steps.

[headrc]

Yes it is one cell. I will turn the sleep mode off on the PC and do another one. I still do not like the fct that the cells drift down to around 3.35V after a full charge ....but next step will be to see how they perform. Thank you Burgerman ....and for all you other folks and what you do here. It is very informative and helpful. RH

[expresso]

Does this mean there are real 20ah Headway cells for sale ?

first i seen of them this size - are they the same size as the 15ah models ? the specs though are not the same as on the headway sites -

if all true and correct - same specs - C rated etc, - this is great - for future maybe - i would have been able to fit 120ah with these cells instead of 105ah with 15ah cells -

looking forward to see how they are in real life use over some time - good job in finding them

[Burgerman]

If he is measuring one cell, and not a pair. And if they ARE headway cells, and if they are not low rate solar storage cells, then yes!

[expresso]

The link to the Cells that was posted above - which he purchased i believe - it does show a different C rate than the Headways we used - shows 1C - and 6C Max burst - again if thats correct - we never know -

[Burgerman]

Yes thats a worry for powerchair use. 1C on a 100Ah pack is only half the amps we need/take when turning, wheelieing or climbing a threshold etc.

If you can get 200Ah of them on board, no worry. If its 60Ah then thats a big worry for longevity. And possibly performance. Theres a reason my RC helis use 70 to 90C with 130C pulse cells.

[headrc]

Yes I truly believe they are Headway and yes they are 20AH and yes they are a lower C rating. Now if that lower C rating will work for applications here ...as well as my own is the question. I will be doing a test for my purposes soon, but it is definitely different then what users here are using hem for. It was my bad to not look at the C rating and compare when I bought these. But the cells so far test to what the seller specs them at ...except for that top charge drifting down about 3% after a charge to 3.6 volts. I was not aware that Lifepo4 did that ...but I am new to Lifepo4. Here is another test with my PC going to sleep ...it again is of a single cell.

[Burgerman]

Is the test of a single cell, or of those two joined together as a block with the orange plastic? Because thats still not clear.

What are you planning to fit this to? And is it an addon or a complete pack.

[headrc]

It is one cell not a two cell block. No, it isn't an add-on. It would be the complete power source for an RC controlled tool carrier ...for electric mowers, weedeaters etc. for my farm's 3 acre yard. This yard is hilly and steep but I don't need a lot of run time as what I usually do with this carrier takes only an hour or two. However, it can pull amps upwards of 120A in spurts due to the steep areas. Most of the time it is pulling around 20 - 20A the way I use it, but climbing the steep banks pulls that 120A current. So I am not optimistic that what I bought will answer the need. Again, my BIG mistake was in not looking at the C rating on these cells and looking mostly at the 20AH rating. Just another one of the stupid things I have done in life. I currently have a Lithium ion pack that I built with a similar C rating as these headways and it performs satisfactorily to a degree. With what I assembled in parallel of those Lithium ion cells (18650 type chemistry, are Boston Power Swing 5300 cells) it has pretty much the same AH rating as these Headways. But my thinking was I was going to get a higher C rating with the same AH with the Headways. Of course that was a major oversight of mine. The plus of the Lithium Ion is I can charge them to a higher voltage of 4.2V ...and they hold that voltage after charge within about .01 to .02 volts. So I am starting with a lot more voltage with a comparable AH pack built out of them compared to these Headways. I may end up using these Headways for another purpose or selling them and looking for other alternatives for that Higher C rating.

[Burgerman]

If you fit twice as many it might last a while. Or risk it as it is and avoid steep slopes etc.

Try a cycle test on those Lithium ion cobalt cells. I dont think they go as high as 5AH... Sounds like optimistic marketing. My bet is half that. http://lygte-info.dk/review/batteries20 ... %20UK.html

Set up a profile and test.

[steves1977uk]

How about posting a pic of those 20Ah cells? Curious to see how much bigger they are compared to the 15Ah ones.

Steve

[steves1977uk]

These must be the cells that are 20Ah... https://www.alibaba.com/product-detail/ ... 1d0dfCW0pb

Steve

[headrc]

I will try and take a picture tomorrow and post it of the Headway's, although they petty much look like what I posted in the original link. Regarding the Boston Swing 5300's Lithium Ion Burgerman, they do perform as the manufacturer states. There is a pretty extensive test of these batteries here:

https://secondlifestorage.com/t-Boston-P...underheart

Although I can do a test on the PL8 to verify.

I have mixed feelings of really putting these Headways to the test for my application ....since I now realize their specs are not really any better than the Swing 5300's. I am leaning to sellingthem , using the Swing 5300 pack for now ...and then getting something with a higher C rating like the Headways many of you are using here and see how that performs.

[shirley_hkg]

Curious to see how much bigger they are compared to the 15Ah ones.

Steve

43---184
doesn't make a good form factor to be put into our G24 battery space .

[shirley_hkg]

This 5500mAh 40900 by HITACHI wins Boston Swing hands down .

Rated @30C ,higher than A123, need only 3 of them to start a 3.5L sedan .

[headrc]

Where can you find pricing and other specs on that Hitachi battery ...using what you stated I do not find either a vendor, pricing or specs for them. I would need that to compare apples to apples. And I certainly was not offering the Swing 5300 as an alternative here ....just saying it is something I have tried and it works fairly well for my application. But we all could use higher C ratings, more AH and cheaper pricing!

[shirley_hkg]

Above is $4.00 a piece .

There are many to choose from , if you are not limited to LiFePO4 .

This 26Ah by Sanyo has very good reviews .

10C rated , @US$12.00

[headrc]

Shirley ...are you a vendor for these batteries? If so ...where can more information be found and a purchase be made if someone wants to make a purchase? If you are not a vendor ...where are you finding them? Product numbers would be helpful.

[Burgerman]

You would need 7S as they are lithium ion (fire, smoke etc) so not really a good idea to be sitting on them unless you are able bodied. So you can get off and escape!

But for other purposes very cheap.

[headrc]

Yes ...very cheap ...but in the too good to be true category? Still wanting product codes and vendor selling information.

[shirley_hkg]

They are all over Chinese-eBay - - - Taobao .

[Burgerman]

They would be OK for large solar bank. As long as charge maximum 4.100V and never below 3.550V

[LROBBINS]

To clarify - Shirley is not a vendor, but "one of us" who happens to live in Hong Kong and, being Chinese-speaking, can read what's on Taobao, and has been wonderfully kind in buying things for those of us who can't navigate that.

[ex-Gooserider]

I'm curious - do these allegedly 20Ah Headway cells have any labeling on them???

I know the 15Ah Headways that I bought a while back had definite labeling on them saying that they were 15000mAh cells, along with a serial number and some other stuff....

The closeup photos I've seen of other size Headways also have labeling of the same sort...

ex-Gooserider

[headrc]

I have been negligent on taking a photo of the 20AH ...due to some other equipment repairs I have had to do here over the last several days. I will do my best to get that taken care of tomorrow ...and check for labeling on them. That is good to know on Shirley ....those batteries she highlighted do sound interesting for my application. Taobao is new to me ...looks like another adventure is in store here.

[headrc]

Yeah ...navigating Taobao looks like an interesting exercise!

[Burgerman]

Hence Shirley_hkg!

[LROBBINS]

BTW - Shirley is a HE