Hi
LFP:
You might with some(all?) LFP even find a slight hysteresis in pack voltage, at
exactly the same SOC..
(most visible if you are in the 30-70% SOC-zone)
depending on ..if you have had a regen or a discharge pulse as your last event,
then the no load voltage seems not to be exactly the
I am not a lithium battery expert. But with any kind of battery, I would do
a load test to identify the problem cells.
Put 20-40 amps on the fully charged battery, and measure the voltage of each
cell in turn. The stinkers will quickly reveal themselves.
Be aware that you may find a
at the end of the charging cycle.
Success!
Cor.
-Original Message-
From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Matthew Quitter
via EV
Sent: Tuesday, August 08, 2017 5:57 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Curtis 1238-6501 State of Charge
Hi Guys,
Thanks
ehicle Discussion List <ev@lists.evdl.org>
Sent: Tuesday, August 8, 2017 12:15 PM
Subject: Re: [EVDL] Curtis 1238-6501 State of Charge
paul dove via EV wrote:
> Sure you can. Voltage is the only way to discern SOC.
> You just can't measure accurately under load. You have to measu
EV <ev@lists.evdl.org>
Sent: Tuesday, August 8, 2017 3:00 AM
Subject: Re: [EVDL] Curtis 1238-6501 State of Charge
In LFP, temperature influences voltage more than SOC in the region of
20% to 80% SOC. The voltage changes just a tiny amount between 20% and
80% SOC.
Basically, if the vol
paul dove via EV wrote:
Sure you can. Voltage is the only way to discern SOC.
You just can't measure accurately under load. You have to measure open circuit
voltage.
www.mdpi.com/1996-1073/9/11/900/pdf
This paper mainly discusses the higher-voltage Li-Ion cells, which have a larger
voltage
tthew Quitter via EV <ev@lists.evdl.org>
>> Sent: Sunday, August 6, 2017 9:13 PM
>> Subject: Re: [EVDL] Curtis 1238-6501 State of Charge
>>
>>
>> On 08/06/2017 07:38 PM, Matthew Quitter via EV wrote:
>>
>>> Hi Guys,
>>>
>>>
EV <ev@lists.evdl.org>
Sent: Sunday, August 6, 2017 9:13 PM
Subject: Re: [EVDL] Curtis 1238-6501 State of Charge
On 08/06/2017 07:38 PM, Matthew Quitter via EV wrote:
Hi Guys,
My 1238-6501 Curtis controller gives very different SOC % for similar
voltages.
For example I've recorded a
nday, August 6, 2017 9:13 PM
Subject: Re: [EVDL] Curtis 1238-6501 State of Charge
On 08/06/2017 07:38 PM, Matthew Quitter via EV wrote:
> Hi Guys,
>
> My 1238-6501 Curtis controller gives very different SOC % for similar
> voltages.
>
> For example I've recorded
Looking at the instructions for the QNBBM battery balancers, they appear
to be able to balance the battery pack and handle a continuous current
of 6 amps. It that correct? Do I have the right model?
If I have the correct model, and they can take 6 amps, then you should
be able to set your
Matthew Quitter via EV wrote:
Thanks guys... but if the charger is turning off at a fixed voltage how do I
get more power into the pack?
Like Bill Dube said; you measure amphours. Shut off the charger when you have
put back as many amphours as you took out (plus a little bit more to cover
Hey Willie,
I've used that website so many times to look at other conversions and never
once thought of putting myself up there. Will do!
Thanks,
Matthew
07966 806 727
On 7 August 2017 at 17:14, Willie via EV wrote:
>
>
> On 08/07/2017 10:58 AM, Matthew Quitter via EV
On 08/07/2017 10:58 AM, Matthew Quitter via EV wrote:
Thanks Bill, sorry I'll try and give you more information.
I don't find a Quitter on http://evalbum.com
If you are there, you should tell us how to find you. If not, you
should consider making an EVAlbum page.
On 08/07/2017 10:58 AM, Matthew Quitter via EV wrote:
Thanks Bill, sorry I'll try and give you more information.
I'm using a Zivan NG3 charger and don't have a BMS at the moment, just a
bunch of QNBBM cell balancers.
Previously I stopped the charge manually when the Curtis was saying 100%.
Thanks Bill, sorry I'll try and give you more information.
I'm using a Zivan NG3 charger and don't have a BMS at the moment, just a
bunch of QNBBM cell balancers.
Previously I stopped the charge manually when the Curtis was saying 100%.
The Zivan also displays a charging progress and it would
The surest way to destroy a pack of LFP cells is to fully charge them and
let then get hot as in over 100F.
Can you tell us the number of cells and their parallel series
configuration? Then specific recs can be made.
You may want to consider cutting of charging before fully charged state is
Hi Michael,
Fortunately in the U.K. it never gets that hot!!!
I've got 25 160Ah Thundersky in series. I believe they're 3.3 nominal and
online it says not to charge over 4V. But I'm never certain about that.
Thanks,
Matthew
Sent from my iPhone
> On 7 Aug 2017, at 12:59, Michael Ross
On 08/07/2017 01:53 AM, Matthew Quitter via EV wrote:
Thanks guys... but if the charger is turning off at a fixed voltage how do I
get more power into the pack?
The voltage rapidly rises as the cells near full charge. Just as it
rapidly drops as they near empty. The cells are supposed to
Matthew Quitter via EV wrote:
Thanks guys... but if the charger is turning off at a fixed voltage how do I
get more power into the pack?
Like Bill Dube said; you measure amphours. Shut off the charger when you have
put back as many amphours as you took out (plus a little bit more to cover
I agree. Voltage on LFP cells is useless for determining the SOC.
The voltage is very constant except at near 100% SOC and at 0% SOC.
You really need information about the middle, and voltage doesn't give
any clue about that.
You need to count the amp-hours, like with an E-meter or a
On 08/06/2017 07:38 PM, Matthew Quitter via EV wrote:
Hi Guys,
My 1238-6501 Curtis controller gives very different SOC % for similar
voltages.
For example I've recorded a pack voltage of 82.2 and had the Curtis show
22%, 31%, 43%.
The pack is made up of 25 Thundersky 160Ah batteries.
With
Hi Guys,
My 1238-6501 Curtis controller gives very different SOC % for similar
voltages.
For example I've recorded a pack voltage of 82.2 and had the Curtis show
22%, 31%, 43%.
The pack is made up of 25 Thundersky 160Ah batteries.
It's getting worse too. Now I'm getting the charger turning off
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