PINNED - Lithium battery conversion/info

[fishinjunky]

Got the pack together now just waiting on my charging leads to charge and test each cell individually then wire it up an test more until it's ready for the chair

[Burgerman]

Have you resisted the temptation to touch your tongue on the terminals?

[Burgerman]

Have you resisted the temptation to touch your tongue on the terminals?

[fishinjunky]

Have you resisted the temptation to touch your tongue on the terminals?

if I don't get these charge cables soon may just have to do a taste test

[fishinjunky]

Here are the cable sizes I used for the lifepo4 build. Did I do ok?

Charging cable:   10 awg
Power cable:        6 awg
Bus cables:          8 awg
Balance cables:   20 awg

All soldered, silicone cables, and marine grade ring terminals.
Using anderson sb50 connectors for charging cable and power cable.
Db9 connectors for balance cables.

[fishinjunky]

What is the best voltage for storage if I'm not using my cells right away?

[Burgerman]

Its not a voltage. Its a state of charge.

Anywhere from 30 to 70 percent by Ah. So fully charge unless they already are. Then discharge by say 40% by Ah. Voltage remains much the same regardless of state of charge unless pretty full or pretty empty.

[fishinjunky]

i started charging, but im only getting 7amps. does that mean its mostly charged?
do i need a balance wire hooked up when charging cells individually?

[Burgerman]

Probably. Has it reached the 3.600V CV?

[fishinjunky]

Probably. Has it reached the 3.600V CV?

Yea it was showing 3.6v and around 7amps. I have the current set at 35amps and end current is 1% and end voltage is 3.6v. I couldn't read IR without the balance leads and for cut off voltage I think is read through the balance leads. Is that why it didn't cut of at 3.6v in cv phase?

Is this correct?
The charger starts with cc " constant current" then once the current starts dropping its goes into cv phase " constant voltage "
If it's pretty much fully charged when I start the çharge will it go right to the cv phase. Which is why only 7amps from the start?

[fishinjunky]

Probably. Has it reached the 3.600V CV?

Yea it was showing 3.6v and around 7amps. I have the current set at 35amps and end current is 1% and end voltage is 3.6v. I couldn't read IR without the balance leads and for cut off voltage I think is read through the balance leads. Is that why it didn't cut of at 3.6v in cv phase?

Is this correct?
The charger starts with cc " constant current" then once the current starts dropping its goes into cv phase " constant voltage "
If it's pretty much fully charged when I start the çharge will it go right to the cv phase. Which is why only 7amps from the start?

Here is a picture

[Burgerman]

They are full when current drops to a very low level. Like around 1/2A. They are 99% or more full now.

[fishinjunky]

They are full when current drops to a very low level. Like around 1/2A. They are 99% or more full now.

I stopped the charge just to make sure. The cell had been charging for over 1hr no change in current or voltage from the start
This is the first charge for each individual cell. Should I let the cell go longer on charge until the current drops all the way an it says done?

I may connect balance wires just to read ir, but haven't decided

[fishinjunky]

I think it needs the balance wires for reading correct voltage and ir

[Burgerman]

Every cell manufacturer is different. What was the current when it stopped falling? Set termination to say 10% greater.

But it should be lower than 6A! Dishcharge it by 10Ah and then recharge it. Note the current when it stops dropping.

[shirley_hkg]

It looks like charging with a CC /CV psu.

Hobby chargers do it the other way. They charge at higher volt to achieve high amp. They charge for a while and stop to measure cell volt, so not to overcharge it .

It's strange that a seller will store or ship with 100% SOC.

[fishinjunky]

Every cell manufacturer is different. What was the current when it stopped falling? Set termination to say 10% greater.

But it should be lower than 6A! Dishcharge it by 10Ah and then recharge it. Note the current when it stops dropping.

Thanks for the tips bm.
That's what I'll do, I'll get it dialed in I'm feeling confident with it. But I really do enjoy tinkering with electronics I never realized it before. If someone new gets a iCharger they should be able to read the last couple of pages of this thread for setting it up. I think I've asked about every question possible.

[fishinjunky]

It looks like charging with a CC /CV psu.

Hobby chargers do it the other way. They charge at higher volt to achieve high amp. They charge for a while and stop to measure cell volt, so not to overcharge it .

It's strange that a seller will store or ship with 100% SOC.

I was wondering the same thing about shipping with 100% soc. Do you think they may have done that sence I had the air shipped?

I'll have more data tomorrow when I put on the balance cables to measure ir and do what bm recommends.

[fishinjunky]

all cells show IR 1.0
is that good?

[fishinjunky]

all cells show IR 1.0
is that good?

Nevermind it's 0.3 ir just measured with the ICharger
That's also what they were advised for

[fishinjunky]

Cell number 1 is charging its says 3.35v and has put in 46ah so far but only charging at 14amps but I have it set at 35amps?

It's been charging for 3hr 15min

[fishinjunky]

Cell number 1 is charging its says 3.35v and has put in 46ah so far but only charging at 14amps but I have it set at 35amps?

It's been charging for 3hr 15min

Here's a picture altogether 77ah put back in. It resets if turned off

[Burgerman]

Why does that say 3.77v???

The cell will not be happy... Its full at 3.600V.

[Burgerman]

How many cells?
The one that shows 3.37V is not full. I have no idea why the charger is not charging at the rate you set unless the othr cells in a pack are almost full. To be honest I cant make sense of that display.

[fishinjunky]

How many cells?
The one that shows 3.37V is not full. I have no idea why the charger is not charging at the rate you set unless the othr cells in a pack are almost full. To be honest I cant make sense of that display.

Just one cell , the 3.37 is the cell. The top left screen is the left channel output the top right screen is the right channel output the bottom right screen is both channels output combined. I have it in sync mode
The bottom left is cell stats. I think the 3.7 is output voltage from the charger. I have end voltage set at 3.6v

[steves1977uk]

3.799v will shorten the life of your cells if the iCharger keeps them that high. My PL8's never exceed 3.599v when I'm doing a full charge once a month. Usually it's 3.575v every week.

Steve

[steves1977uk]

Also it says the PSU is delivering just 2.2Ah??? The info screen is just too messy to understand what is actually happening.

Steve

[fishinjunky]

Also it says the PSU is delivering just 2.2Ah??? The info screen is just too messy to understand what is actually happening.

Steve

I sea that, I think that's the psu stats going into the charger.
DC 24.254v 2.2A. 0.4AH could the 2.2A be why I'm only getting 13amps?

I have a 24v 69amp psu. I have max input Amps set to 65amps

[fishinjunky]

I figured it out the alligator clips aren't secure enough causing a spike in voltage making the charger inhibit the amps so it doesn't cause the voltage to climb higher. In conclusion it's the alligator clips not giving a good enough connection

[shirley_hkg]

In conclusion it's the alligator clips not giving a good enough connection

Hope you didn't clip on the stud. It's high resistance then, and high heat.