Lifepo4 video tutorials

[sacharlie]

Do you have any?

Interesting how this guy added extra cables to speed up the balance.

http://www.youtube.com/watch?v=hiyr_Yg0E6c

[Burgerman]

First thing he does, connect all in parallel to balance is already wrong... You cannot balance LiFePO4 at any voltage below around 3.45 to 3.50V which means you can only balance them on charge. What he shows wont work. Since he is ignorant of 2 things. And adding extra cable didnt spee up balance it just made them read the same due to lower total buss bar resistance. If every cell was at say 3.32000000V then they STILL are likely to be several Ah out of balance. You cannot balance at that voltage.

1. cells at around his 3.316 to 2.320V can be 4 or 5 full Ah different to each even if all were to STAY at the exact same voltage (and they wont) when he disconects them. He is another clueless idiot trying to teach others! And adding extra lumps of cable wont chage this one bit! He is ignoring that cells have resistance too, so thinks that they will stay at this voltage once disconnected...

2. A tiny temperature change at this voltage can also mean a few mV higher or lower. So its quite possible that holding your hand on one cell will discharge a few Ah from it, into the rest! There is only one way to balance them. Thats charge full, above the natural 100 percent full voltage, which means holding them at 3.45V or higher for a good while till current drops off to almost nothing. When his still unbalanced pack approaches full, the actual fullest cells will go off the scale while the rest stay below 3.4xx. And he has nothing on there to stop it! That guy is clueless. And most of these vids are not much better.

Theres hundereds of battery misinformation vids made by retards all over utube.

[Burgerman]

Heres another one talking bollocks https://www.youtube.com/watch?v=tbaeMWdDlqY

But sounding like an expert (he thinks!)

[steves1977uk]

And the worst part is people actually BELIEVE they're correct and copy them!

Steve

[expresso]

You know the more i see these videos - the better i feel - i am no expert here but my packs look better than most of these videos - whats all the sloppy wiring and extra boards on there - fancy screens to show off - even the other video - hes another one i cant watch

BM - you should consider starting a Youtube channel and every now and then make a real good video - winter is coming - you may have some time to set the record straight everyone seems to want to get fancy and do extra to make it better etc, - when all they doing is extra work - complicated mess of wiring - BMS - and talking -

for a newbie trying to learn - will just scare them off - i know i was one of them who still gets worried when doing things but i rely on correct information that i get from here - or else i wouldnt have never done it if i had to follow those videos -

[Burgerman]

I cant watch all those hundreds of battery experts on utube. I never saw one with the slightest clue about what they were doing yet. And all teaching each other as if they were experts. I cant bear it. If I did my own vids I would have hundreds of arguments with ill informed half wits over and over. Whats the point? Utube is mostly for dummies.All trying to get clicks and ££$$ ... No matter that they are all talking crap.

[expresso]

i know but you would be doing it the right way - who cares what the others say - let the users decide who makes sense - and who to follow - i understand though it would be too much consuming time to go back and forth with idiots -

you can just do it and not worry about what others say - like that other wheelchair guy - Norm something - he makes the videos tests chairs etc, - hes ok to watch sometimes - but you can just work on the battery ends - show your chair - show others what can be done and how -

i guess thats what this site is for then -

just an idea -

[Burgerman]

i know but you would be doing it the right way - who cares what the others say - let the users decide who makes sense - and who to follow

I dont want followers! I want people to think! And thats the problem it will just add to the confusion, they dont know enough to see who is right and which ones are idiots.

Like that guy in the first video. He thinks he has balanced the cells. He may have done the exact opposite. Cell voltage varies between cells by a few mV at the SAME state of charge depending of how similar each cells chemistry, or batch, or temperature, is. They all vary a little. So balancing them at 3.3xV can and often will unbalance them! Thats why I had to get Celpro to redo the firmware allowing 3.4V and 3.5V balance start. It used to automatically start at 3.30V regardless which put the cells well OUT of balance at the top. Taking hours to re-balance. Because they didnt get it either. And also to allow 350mV cell voltage spread without error and "safety charge" of 500mA kicking in... as the full ones suddenly shoot up and go sky high exceeding the previous 150mV limit. Amongst half a dozen other things. I did this when using the hyperion because at that time the PL8 was unusable for lead and lifepo4. I got them to understandthe problems and they fixed it.

[shirley_hkg]

It's ignorance that started all these .

[sacharlie]

Any videos on the pl8 charger?

[Burgerman]

To show what? The thing is self explanitory. Theres hundreds of possible settings and options and combinations. You really need to understand batteries and then you will know what to select and why for any scenario. There is of course hundreds of such videos on utube, allmost always clueless. Theres also a section on it on here. But to charge lead or large LiFePO4 packs beyond hobby size you also need some modified presets as a starting point. Same with large nickel based cells. For things like the iBot.

[sacharlie]

Hooking up 24v & 48v lifepo4 packs. With the 2 channel charger. For 24v is there a benefit or not, to charge 4 cells in series on each channel over 8 in series on one channel? That's what you have to do for 48v anyway.

I should change my name to Many???

[Burgerman]

Hooking up 24v & 48v lifepo4 packs. With the 2 channel charger. For 24v is there a benefit or not, to charge 4 cells in series on each channel over 8 in series on one channel? That's what you have to do for 48v anyway.

No benefit. Dont buy the dual one anyway. Its not as good as 2x pl8 for a bunch of complex reasons. One being that it cant charge a 48V battery. Without turning it into 2 24v ones that are seperated electrically. To do with programming options, balance port capability, as well as what it allows you to set and configure. And because neither output is isolated (floating) as both negatives are tied. Meaning you must seperate the battery into two parts to charge it. Always use 2x PL8 clipped together as one as they do, to charge above 8S. With isolated floating power supplies. You can clip any number together to charge any cell count safely.

Extreme example. Teslas bigger 356.4V battery is 85 kwh and only 77kwh is ever allowed to be used. And 99S according to the math which surely should be 100 but whatever. So 99 divby 8 is 12.3. So you will need 13 PL8s. And that will charge it at 40A given enough power, in just a couple of hours. Maybe 5. As 13x 1400 watts is 18kwh returned per hour, 4.2h to end of CC and 30 mins CV? 3x faster than their own home charger. And cheaper. But your electricity meter will explode.

Here in the USA GREED is GLORIFIED. As it should be! It makes the whole of your economy and country richer, meaning even the poor have a better standard of living than anywhere in the world because of it. Better than the rich in some socialist countries! The TOP 0.25% pay 1000s of times the amount of tax that the WORKING MIDDLE CLASS do, and while they are at it also creates the middle classes jobs and helps raise gdp and so also everyones standard of living and wealth... Remove their driving force even more than you do already by taxing the rich even more, or remove them from the system completely, and everything you depend on is gone. But socialists refuse to grasp this. And so we get bankrupt countries and massive debt, suffering and starvation, over, and over, and over every single time its tried. And still they are too stupid to grasp it...

[Williamclark77]

Extreme example. Teslas bigger 356.4V battery is 85 kwh and only 77kwh is ever allowed to be used. And 99S according to the math which surely should be 100 but whatever. So 99 divby 8 is 12.3. So you will need 13 PL8s. And that will charge it at 40A given enough power, in just a couple of hours. Maybe 5. As 13x 1400 watts is 18kwh returned per hour, 4.2h to end of CC and 30 mins CV? 3x faster than their own home charger. And cheaper. But your electricity meter will explode.

Good luck finding a household supply that could power more than a few at once maxed out!

There are other chargers capable of doing up to 14s without needing to split the pack, charge separately, or use two chargers.

[Burgerman]

But they dont have the power or the PC software or the balance current and more importantly they dont allow you to choose enough options. And many have built in restrictions of either time, cell unbalance limits, upper or lower balance charge point start points, or termination current settins that are unsuitable or missing...

I have managed 2 on one wall socket no prob... And third one in the kitchen charging my quadcopter at 40A. That all worked. The other 10 yill need a few extention cables to all your your neibours houses. Its this that makes mass usership of electric cars like the tesla unfeasable! The grid and the wires in the streets will never be able to cope. And the power stations will all be overloaded by 3x at least as people sleep!

[sacharlie]

Here in the USA GREED is GLORIFIED. As it should be! It makes the whole of your economy and country richer, meaning even the poor have a better standard of living than anywhere in the world because of it. Better than the rich in some socialist countries! The TOP 0.25% pay 1000s of times the amount of tax that the WORKING MIDDLE CLASS do, and while they are at it also creates the middle classes jobs and helps raise gdp and so also everyones standard of living and wealth... Remove their driving force even more than you do already by taxing the rich even more, or remove them from the system completely, and everything you depend on is gone. But socialists refuse to grasp this. And so we get bankrupt countries and massive debt, suffering and starvation, over, and over, and over every single time its tried. And still they are too stupid to grasp it...

My sig_line seems to be a dig_line to you.

[Burgerman]

No it simply shows that you dont understand economics in any way.