# Warning...warning



## kennybobby (Aug 10, 2012)

It looks like cell#1 was likely your weak link, the rest may be okay. All it takes is one bad cell to spoil the pack. Test them individually to determine condition.


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## muskatten (Dec 5, 2015)

Hi Kennybobby.... A friend counted out after the diagram that these cells have an internal resistance of 1,8 mOhm
And in Sinopoly datasheet says that the cells have 0.4 mOhm so this is a big difference ...


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## favguy (May 2, 2008)

Seems a bit off to "Warn us about shopping with Mike" on here. Have you brought this to his attention? I'm sure he'll rectify an issue with a weak cell under warranty for you.


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## muskatten (Dec 5, 2015)

I had 14 days return and 1 year warranty ... When I after 3 days asked about the return ... Mike rejected the possibility


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## muskatten (Dec 5, 2015)

Hello ... I have a query. is this a normal discharge curve (discharge of about 87A for a total of 90min 15+15+60 min total out 130A) on a 200A LiFePO4 battery


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## Karter2 (Nov 17, 2011)

muskatten said:


> Hello ... I have a query. is this a normal discharge curve (discharge of about 87A for a total of 90min 15+15+60 min total out 130A) on a 200A LiFePO4 battery


 It depends on the initial state of charge.
Were they fully charged ? 
At 13.2v flor a 4 cell pack, they could be at almost any state of charge.
Cycle them a few times and then do a capacity check.


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## muskatten (Dec 5, 2015)

Hi .. It might be a little difficult to see, but the upper left corner you will see that voltage was 13:26v at start of test.....but what surprises me is that voltage drops immediately with over 0.5V ..... is this normal for new cells? 



Karter2 said:


> It depends on the initial state of charge.
> Were they fully charged ?
> At 13.2v flor a 4 cell pack, they could be at almost any state of charge.
> Cycle them a few times and then do a capacity check.


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## Karter2 (Nov 17, 2011)

Have you looked at the spec sheet for that cell .?
At 3.3v static, they are not fully charged...hence your apparent lack of capacity.
The voltage sag(0.15 v/cell) is not untypical for that cell part way down on its capacity curve, under that level of load.
http://files.ev-power.eu/inc/_doc/attach/StoItem/2772/GWL-Sinopoly_SP-LFP200AHA_Specification_v2.pdf


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## muskatten (Dec 5, 2015)

Thanks for your answer .. My LiFePO4 charger says that the battery was charged at 95.2%, when I saw that a cell rushed away to 3,64v why I shut off the charger for not the cell would be overloaded ...Thanks for the link ... I've seen it before .... and that is why I doubt that all cells are ok .... for you see so shall not volts rage down with over 0.5V ...


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## Karter2 (Nov 17, 2011)

muskatten said:


> ?.... A friend counted out after the diagram that these cells have an internal resistance of 1,8 mOhm
> And in Sinopoly datasheet says that the cells have 0.4 mOhm so this is a big difference ...


Most of that difference is because the 0.4mohm IR quoted on the data sheet is an AC impedance measurement @ 1kHz, Whilst the 1.8mohm IR calculated from the graphs is a DC Resistance .
DC IR is always much higher than AC IR.


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## muskatten (Dec 5, 2015)

What happens here .... should the cells behave like this ... charging with solregulatorn same time as some automatic start (1-3A max discharger)... I am so grateful if someone can explain this to me ...


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## pm_dawn (Sep 14, 2009)

I would suggest that you take a look on your connections to the cellog.
It seems that cell1 falls with the same voltage as the cell2 rises.
I think you have something weird in your cell voltage wires going to the cellog.
It looks like you get fluke readings.

A picture of the cell voltage wires to the Cellog would be good.

You can also try at the swedish forum and I'll answer you there.

Regards
/Per


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## muskatten (Dec 5, 2015)

Tack Per..... Now I have solved the problem ... the cable between the cells and celllog8 was too long and gave misleading information ...And I also want to pray Mike at Indra apologize for my suspicions ... and I must blame my poor knowledge ... I'm no electrician but an interior carpenter with many ideas / Peter N 



pm_dawn said:


> I would suggest that you take a look on your connections to the cellog.
> It seems that cell1 falls with the same voltage as the cell2 rises.
> I think you have something weird in your cell voltage wires going to the cellog.
> It looks like you get fluke readings.
> ...


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## muskatten (Dec 5, 2015)

I forgot the picture of my first log, where everything is ok ..


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## glyndwr1998 (Apr 27, 2013)

I'm glad you've found your fault.

I personally found,it very difficult to believe that Mike from Indra would not sell anything other than goods that are in good order and fully support them.
It is not worth his good name as a well respected valued member to do anything differently other than to provide a sound professional service.

I am hoping to call on the services of his company in the very near future fro a project that is in the planning.

Anthony.


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## muskatten (Dec 5, 2015)

*Hej Per... Vilket svensk forum menar du.??*


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## pm_dawn (Sep 14, 2009)

muskatten said:


> *Hej Per... Vilket svensk forum menar du.??*


http://elbil.forum24.se/elbil.html

där du redan har tittat in lite.....

Mvh
/Per


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