Balancing LiFePO4s

[nicknorman]

Just now, Dr Bob said:

I am pretty sure you just disconnect the top wire which is the -ve from the battery. The display is dead when you do that.

Provided it then doesn't take any current from the other cells, that would be easy to do then. Just electronically isolate the one wire when the device goes to sleep.

[Dr Bob]

3 minutes ago, nicknorman said:

Provided it then doesn't take any current from the other cells, that would be easy to do then. Just electronically isolate the one wire when the device goes to sleep.

Here's the link to the user manual for the BG 8S. You should be able to confirm that one wire cuts the power.

https://www.isdt.co/down/pdf/BG-8S_en.pdf

[ditchcrawler]

I just came across this video on Facebook, I know very little about Lithium batteries and have not watched it all through 

 

[Dr Bob]

Yeah, love the enthusiasm!

[nicknorman]

10 hours ago, Dr Bob said:

Here's the link to the user manual for the BG 8S. You should be able to confirm that one wire cuts the power.

https://www.isdt.co/down/pdf/BG-8S_en.pdf

Thinking about it, the project will probably need to have a display of some sort (ie for Module 1) so it might as well display cell voltages - probably just as numbers, CBA to programme graphics!

[MoominPapa]

1 hour ago, nicknorman said:

Thinking about it, the project will probably need to have a display of some sort (ie for Module 1) so it might as well display cell voltages - probably just as numbers, CBA to programme graphics!

When choosing a display, be aware that OLED displays have limited life. I've just had to code  a screen-saver for my BMS

 

MP.

 

[TheBiscuits]

35 minutes ago, MoominPapa said:

OLED displays have limited life

 

 One of the main problems of OLED displays is the limited lifetime of the OLED materials. In past years we have seen great advances in this area, and today OLED materials are quite long lasting - with material lifetime reaching million hours or more.

from:

https://www.oled-info.com/oled-lifetime

 

How long are you expecting?!

[MoominPapa]

8 hours ago, TheBiscuits said:

 

 One of the main problems of OLED displays is the limited lifetime of the OLED materials. In past years we have seen great advances in this area, and today OLED materials are quite long lasting - with material lifetime reaching million hours or more.

from:

https://www.oled-info.com/oled-lifetime

 

How long are you expecting?!

Well, after a year or so (9000 hours, roughly) the pixels in areas which are normally lit in the default, always on, display are noticeably dimmer than pixels elsewhere which are normally dark, so not 1 million hours, for sure.

 

MP.

[ditchcrawler]

10 hours ago, TheBiscuits said:

 

 One of the main problems of OLED displays is the limited lifetime of the OLED materials. In past years we have seen great advances in this area, and today OLED materials are quite long lasting - with material lifetime reaching million hours or more.

from:

https://www.oled-info.com/oled-lifetime

 

How long are you expecting?!

That is over 100 Years I wonder who timed them

Edited November 16, 2019 by ditchcrawler

[Dr Bob]

If anyone is half thinking about buying 2nd hand batteries to use on their boat, then this video is very useful in what you are letting yourself in for. No...it's all good.

It talks about Tesla batteries but it is relevant for most used batteries from cars or other EVs.

The stuff on how to choose a 2nd hand one is good.

I reckon there must be a good business opportunity for someone to source these batteries from scrapped EVs and sell 'em to the sewer tube market. Maybe only a few sales now but in a year?