Search found 96 matches

by docware
May 26 2019 1:32am
Forum: Battery Technology
Topic: Panny or Sanyo?
Replies: 44
Views: 1433

Re: Panny or Sanyo?

Dak 77, if you build 8p pack with GA, your wife will love it for next 10 years. And you also.
By the way, internal resistance GA and PF is nearly the same.
by docware
May 26 2019 1:13am
Forum: Battery Technology
Topic: battery condition
Replies: 19
Views: 648

Re: battery condition

Odessadream, installation of simple cheap voltmeter can help you with remaining capacity reading (or state of charge – SOC). And you can better decide when to recharge again. Definitely not immediately after each ride. People here are giving you good advices regarding charging. 908292-1.jpg I just r...
by docware
May 26 2019 12:29am
Forum: Battery Technology
Topic: battery condition
Replies: 19
Views: 648

Re: battery condition

Yes, regular checking of cells imbalance is in such case advisable, of course. And of course, BMS is still connected for emergency.
by docware
May 25 2019 5:14pm
Forum: Battery Technology
Topic: battery condition
Replies: 19
Views: 648

Re: battery condition

My battery 10s5p Sanyo GA is now 2 years old. Last year I started to charge to cca 40 – 41 V. So I am running this battery without balancing now for nearly 1 year. The cells are constantly within 3 mV range.
by docware
May 25 2019 4:41pm
Forum: Battery Technology
Topic: battery condition
Replies: 19
Views: 648

Re: battery condition

Balancing is practically unnecessary if you have new cells REALLY produced from LG, Samsung or Sanyo.
by docware
May 25 2019 7:52am
Forum: Battery Technology
Topic: How solar panel impact battery life for ebike?
Replies: 24
Views: 689

Re: How solar panel impact battery life for ebike?

How solar panel impact battery life for ebike ? Negatively, if you will be succesfull in your intention, as dwelling at higher SOC is negative for battery lifetime. https://www.researchgate.net/publication/328086745_Extending_Battery_Lifetime_by_Avoiding_High_SOC So you invest your money and effort ...
by docware
May 25 2019 7:38am
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 65
Views: 2324

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E

Statement from flippy about better endurance of 18650 is probably not based on trustful data, if any. Regarding the price – total 21700 battery price can be this year very close to 18650 battery, depends on the specific configuration.
by docware
May 24 2019 2:26pm
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 65
Views: 2324

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E

Hi Pajda,

thank you for sharing your data. So Samsung 50E seems to be very good cell. Can you please compare 50E with LG M50 ? Can you please compare 50E to 18650 (MJ1, M36, GA, 35E, VC7) ?

docware
by docware
May 24 2019 12:32am
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 65
Views: 2324

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E

Similar, not different :

https://endless-sphere.com/forums/viewt ... 8#p1450798

By the way, Sanyo 20700B as younger, but bigger brother of Sanyo GA is also interesting cell for ebikes with its capacity 4100 mAh and 25 miliohm DCIR at 3,8 V/25 °C.
by docware
May 23 2019 2:47pm
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 65
Views: 2324

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E

Yes, I believe that we can trust to Pajda´s lifetime cycling test results.
by docware
May 23 2019 11:21am
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 65
Views: 2324

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E

Better, as capacity at 2 A discharge for example. But I would rather say very similar.

Samsung 50E versus LG M50.jpg
by docware
May 23 2019 10:03am
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 65
Views: 2324

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E

Yes, fortunately now we have cells like Samsung 50E or LG M50. LG maybe a little bit better, but generally both very similar and interesting for ebikes. :thumb:
by docware
May 23 2019 1:32am
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 65
Views: 2324

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E

Easy_Rider wrote: „I would not exceed, if I were you, the 0.3C for the battery.“ (charging) „I fit my battery to the Motor and controller I use and to the landscape and season I´d like to drive“ „On 13S3P I have around 1,80A - 2,20A CDR on every cell.“ You obviously know a little bit about Li-ion ce...
by docware
May 22 2019 3:01pm
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 65
Views: 2324

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E

Are you sure that you agree with Matador ? 😊
Just read carefully his post. 😊


Docware
by docware
May 22 2019 2:27pm
Forum: Battery Technology
Topic: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E
Replies: 65
Views: 2324

Re: Panasonic/Sanyo NCR20700B vs Samsung INR21700-50E

Just few remarks : 1) Zeroair finished measurement at 2,8 V. Discharging down to 2,5 V according specification is giving capacity nearly 5 000 mAh in the range 1 – 5 A. ( equipment : calibrated ZKETECH EBC A-10H, BF-2A fixture, 25 ±1 °C) Samsung 21700 - 50E f.jpg 2) Frankly, Zeroair measurement seem...
by docware
Apr 10 2019 6:01pm
Forum: Battery Technology
Topic: Li-ion battery charger suggestion
Replies: 30
Views: 1008

Re: Li-ion battery charger suggestion

1) As the current drops, the diode temperature drops also. This in fact little bit shifts and compensates the voltage drops. 2) Charger usually stop charging at the same low current, so we can expect the same voltage drop and the same final voltage. 3) It is not important to have always absolutely t...
by docware
Apr 10 2019 11:44am
Forum: Battery Technology
Topic: Li-ion battery charger suggestion
Replies: 30
Views: 1008

Re: Li-ion battery charger suggestion

Frankly, don´t understand why you want so complicated solution. Charger for 36 V is OK for you. So you just need to wire in serial with 48 V charger general purpose 20 A diode ( for example FT2000AB, FT2000KB, FT2000AD, ….. ) to decrease final voltage . 52765.jpg 1 diode reduce voltage by cca 0,6 - ...
by docware
Mar 16 2019 9:01am
Forum: Battery Technology
Topic: DIY HI POWERED PACK: First time, General questions
Replies: 60
Views: 2219

Re: DIY HI POWERED PACK: First time, General questions

Yes, you are missing the fact that your expectation regarding both 18650 and 21700 is unrealistic. care to explain? I am afraid that your project is unrealistic. Warming of LG HG2 and Samsung 30Q in the closed battery pack even at 5A discharge is too high. Samsung warming 30Q 2A v 5A.jpg At 5A disc...
by docware
Mar 15 2019 2:25pm
Forum: Battery Technology
Topic: DIY HI POWERED PACK: First time, General questions
Replies: 60
Views: 2219

Re: DIY HI POWERED PACK: First time, General questions

Yes, you are missing the fact that your expectation regarding both 18650 and 21700 is unrealistic.
by docware
Mar 15 2019 1:21pm
Forum: Battery Technology
Topic: DIY HI POWERED PACK: First time, General questions
Replies: 60
Views: 2219

Re: DIY HI POWERED PACK: First time, General questions

Well, I didn´t catch you mean aged cells estimation. I understand that better DCIR doesn´t ensure better lifecycle.
by docware
Mar 15 2019 11:56am
Forum: Battery Technology
Topic: DIY HI POWERED PACK: First time, General questions
Replies: 60
Views: 2219

Re: DIY HI POWERED PACK: First time, General questions

SamRich wrote:
Mar 15 2019 9:18am

I included it with a best guest of IR.
The IR you included seems to be out of reality. Real values should be around these values ( ± 1 miliohm ) :


ACIR v DCIR.jpg
by docware
Mar 08 2019 8:32am
Forum: Battery Technology
Topic: LiFePO4 in 18650 format?
Replies: 78
Views: 3757

Re: LiFePO4 in 18650 format?

No, I was nearly all the time speaking about capacity measurement. Unfortunately I didn´t differ enough the questions to cycle test. (" Let´s make a summary. Cycle test consist of : charge 1,3 A to 4,05 V, discharge 2,75 A to 3 V. Cut off current ? Rest times between cycles ? ") flippy, flippy, from...
by docware
Mar 08 2019 6:24am
Forum: Battery Technology
Topic: LiFePO4 in 18650 format?
Replies: 78
Views: 3757

Re: LiFePO4 in 18650 format?

Flippy, I consider cycle testing really important. So I am thankful to any information. Hope I´m not bothering you too much. 😊 Probability that any cell have only 0,5 % capacity loss after 500 cycles between 4,05 and 3 V is very very low. Value 0,5 % seems to be rather accuracy of the equipment. Loo...