Re: [EVDL] Curtis 1238-6501 State of Charge

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

Re: [EVDL] Curtis 1238-6501 State of Charge

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

Re: [EVDL] Curtis 1238-6501 State of Charge

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

Re: [EVDL] Curtis 1238-6501 State of Charge

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

Re: [EVDL] Curtis 1238-6501 State of Charge

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

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 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

Re: [EVDL] Curtis 1238-6501 State of Charge

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, >>> >>>

Re: [EVDL] Curtis 1238-6501 State of Charge

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

Re: [EVDL] Curtis 1238-6501 State of Charge

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

Re: [EVDL] Curtis 1238-6501 State of Charge

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

Re: [EVDL] Curtis 1238-6501 State of Charge

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

Re: [EVDL] Curtis 1238-6501 State of Charge

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

Re: [EVDL] Curtis 1238-6501 State of Charge

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.

Re: [EVDL] Curtis 1238-6501 State of Charge

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%.

Re: [EVDL] Curtis 1238-6501 State of Charge

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

Re: [EVDL] Curtis 1238-6501 State of Charge

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

Re: [EVDL] Curtis 1238-6501 State of Charge

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

Re: [EVDL] Curtis 1238-6501 State of Charge

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

Re: [EVDL] Curtis 1238-6501 State of Charge

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

Re: [EVDL] Curtis 1238-6501 State of Charge

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

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 pack voltage of 82.2 and had the Curtis show 22%, 31%, 43%. The pack is made up of 25 Thundersky 160Ah batteries. With

[EVDL] Curtis 1238-6501 State of Charge

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