100Ah LiFePO4/20Ah LTO discharge test w/ SOC curve

[Will Prowse]

Testing out my new capacity tester and after a 10 hour test, it gave me these results:



I do not want to mention the name of the tester till I ensure it is accurate. (Snoobler approves. It's a CBA IV)

It is really fun to plot this data on a graph ? so much fun! I need to do this with LTO.

 

[snoobler]

Bro...

Come on.

It's accurate.

I'd know WMR any place I see it.

CBA FTW.

 

[Will Prowse]

Bro...

Come on.

It's accurate.

I'd know WMR any place I see it.

CBA FTW.

Dang you're good!!! Haha ?

I think I need to redo the battery cables. Just need to ensure the conductors are oversized. I don't trust these cheap clamps:

 

[snoobler]

I've had one for about 6 years.

The one downside is that damn Anderson. It's unreliable as crap. I actually disassembled it and soldered leads directly to the posts. It's the reason why I won't tolerate Andersons ever.

 

[snoobler]

And with your sick youtube dough, you should get an amplifier... tests those 280Ah at 1C!

 

[Will Prowse]

I've had one for about 6 years.

The one downside is that damn Anderson. It's unreliable as crap. I actually disassembled it and soldered leads directly to the posts. It's the reason why I won't tolerate Andersons ever.

Oh right! That's what I was worried about. Ok good to know. My anderson's had some wiggle and I felt that to be inappropriate considering the test at hand.

 

[snoobler]

I use 8awg for everything. The superworm stuff from Acer Racing. Such fine strands... so floppy...

 

[Will Prowse]

And with your sick youtube dough, you should get an amplifier... tests those 280Ah at 1C!

That thing is a beast. I just might. That would be amazing!!!

 

[Will Prowse]

I use 8awg for everything. The superworm stuff from Acer Racing. Such fine strands... so floppy...

Smart!! The good stuff

 

[snoobler]

Oh right! That's what I was worried about. Ok good to know. My anderson's had some wiggle and I felt that to be inappropriate considering the test at hand.

Yeah. When you can influence your curve by wiggling the connector... bad bad bad.

 

[Will Prowse]

Yeah absolutely. Yikes.

I have to go to bed now, but I'll try to test some more packs soon. Such a fun device.

I wish it was cheaper. Quite a pretty penny considering the parts and software.

 

[snoobler]

That's where you and I differ. You have the sense to get a good night's sleep. Oh, and I'm not famous beyond being a schmuck on a few forums.

 

[Dzl]

I am a sucker for data, charts, and graphs!

I am looking forward to seeing how you put this to use

 

[Steve_S]

Wouldn't it be nice if you could get a Tester setup that was PC Connected and logging data while it runs through the charge/discharge cycles, logging not just the Voltage & measuring wh & such but also the cell IR as well with settable logging point (say log at every 0.5V charge or every 0.25 or even 0.10 and so on.

They are out there BUT not for the hobbyist / diy'er. Considering all the tech out there that we all use, you'd think that some creative soul would have come up with a small battery tester with such capabilities.

Here is what the Big Boys play with... $ prices are no listed, if you have to ask, you can't afford it.
Battery Pack Machine Suppliers, Battery Tester For Sale (batterymaking.com)

 

[JoeHam]

That device has had favorable reviews in the past from various Ham Radio magazines.

 

[Steve_S]

LINKS PEOPLE - LINKS.
Here is the link to the Product Pages for the Tester.

West Mountain Radio - CBA IV - Computerized Battery Analyzer

@Will Prowse a suggestion.
I was just perusing the Main Site and realized a missing item(s). Recommended/Suggested Bench Power Supplies for Top Balancing. There has to be at least 3 Known Good at different price points that people could use and be referred to.

 

[JoeHam]

LINKS PEOPLE - LINKS.

I thought Will had asked for time to evaluate the accuracy in post #1 so I held off.

 

[Will Prowse]

Just ordered the $1000, 500W CBA IV. Now we can have accurate data on any pack I test. Should be worth it ?

10A limit for 12V pack took over 10 hours to test. And that's after charging for 2 hours. This 500W model should reduce that to under 3 hours for a 1280Wh pack.

 

[Deleted-User]

I use 8awg for everything. The superworm stuff from Acer Racing. Such fine strands... so floppy...

Yep..look pretty flexible to me

https://www.bigsquidrc.com/wp-content/uploads/2012/02/acer_worm.jpg

Edit: Snoobs, what do you use in place of Andersons?

 

[snoobler]

Yep..look pretty flexible to me

https://www.bigsquidrc.com/wp-content/uploads/2012/02/acer_worm.jpg

Edit: Snoobs, what do you use in place of Andersons?

I either solder something direct or use ring terminals bolted together. There are some cases where I use bullet connectors, but I use the type that are flared, and once installed, I zip tie them to each other to provide pressure for both to maximize connection quality. I essentially try to avoid any type of temporary connection.