Revolectrics

[Burgerman]

Did you notice that its those with the least technical understanding that cant understand how aything works that have the most "opinion"?

Until they can control what the charger does, be able to tell it when balance is complete, be able to throttle the balance current and charger output proportionally, then all the fancy "modern" settings in the world dont make a blind bt of difference. And the fire hazard remain too.

But let them be happy in their ignorance. I can only advise. They can argue their nonsense and do exactly as they want. Have shortened service life, less reliability, unknown balance situation, much less range than doing it properly, slow charge times, and additional fire risk if they choose. Most of the ignorant are already happy in their ignorance and doing exactly this. Hence the occasional horror stories and much reliability issues. Their ignorance, their choice.

Meanswhile those with a brain will be on the lookout for another decent hobby style integrated chargerbalance system like the PL8. I am watching hobby forums for recommendations to test.

[shirley_hkg]

100mA is the biggest I've seen .

The reason is simply. Higher balance current means more HEAT , that force ventilation will be inevitable.

[Burgerman]

I know all that. Its those that have all the strong opinions about how marvelous they are, the ones that have no clue how they work, that dont!

Even if they had 1A balance, they STILL cannot control the charge current. Cannot throttle the charger so that the even 1A draw down isnt overtaken by the 40A charger, cannot tell it if and when balance is complete, and cannot tell the charger to end when the correct termination current happens. So they are pretty much screwed. But "modern" ones mst be so much better! They need to be a part of the charger to do this stuff correctly. Not fed DC by 2 wires from a charger that doesent know what its meant to do or when its meant to do it.

[Gnomatic]

Did you notice that its those with the least technical understanding that cant understand how aything works that have the most "opinion"?

The Dunning-Kruger Effect in action.

[Burgerman]

This:

In 2011, Dunning wrote about his observations that people with substantial, measurable deficits in their knowledge or expertise lack the ability to recognize those deficits and, therefore, despite potentially making error after error, tend to think they are performing competently when they are not:

"In short, those who are incompetent, for lack of a better term, have little insight into their incompetence—an assertion that has come to be known as the Dunning–Kruger effect". In 2014, Dunning and Helzer described how the Dunning–Kruger effect "suggests that poor performers are not in a position to recognize shortcomings in their own performance".

Yes appears to be running wild in here at the moment. Which is why I have given up trying to explain what to me is blindingly obvious. As simple as 2+2. I tried repeatedly for years to explain complex things to the average person and usually failed. Its patently obvious that some here are either incapable of understanding anything complicated, simply dont have the mental capacity needed for complex subjects (the very same skills needed to recognise their lack of understanding/mental ability). Or are willfully ignorant and dont care about the truth.

So carry on! I tried. And I am correct. And if only you could understand technical or complex things you would see that too.

[Arima]

I have to admit I am one of those with little knowledge but so thankful for a place to discuss it all. Today I'll be searching for that one thread that explains what we want to happen to the cells in a pack throughout a cycle. I know BM has written it all a few hundred times already.

Ordered the ISDT P30 as I was looking at a smaller ISDT model before BM mentioned the big one. I'll be happy to share the results when new cells arrive. Hopefully it will help ease the pl8 anxiety.

[sacharlie]

How about 8 single cell charges?

[biscuit]

I have given up trying to explain what to me is blindingly obvious. As simple as 2+2.

Well please do not give up on us! It isn't intrinsically obvious, in fact. People have to twist their head around a lot of very new concepts to get hold of this stuff.

[Gnomatic]

Ordered the ISDT P30 as I was looking at a smaller ISDT model before BM mentioned the big one. I'll be happy to share the results when new cells arrive. Hopefully it will help ease the pl8 anxiety.

Good luck, Arima. I look forward to reading about your experience with it.

[biscuit]

How about 8 single cell charges?

not going to work unfortunately as each cell might take many hours.

[Burgerman]

If you had say 8 decent 3.600V chargers that you can find. That were ISOLATED output (zero measured Ohms between every Negative on the chargers) with 25 to 40A capability then that will work well. PROVIDED you can set the termination current for each to the correct value.

Thats exactly what a PL8 is doing by a different method. But that means a lot of 40A cables. 16 of them in fact. You could do it with 9 if you were to do a little trick wiring. But still. And you have to find such a thing with isolated output.

[Burgerman]

What will be important there is if its possible to set a termination current in mA that is user defined. Rtaher than being some percentage of charge current. And if it can be set to balance only above 3.50V. And not terminate until balance ends. Those are the critical things. And that it doesent have 101 safety guards and traps to trip us up. It may be OK. I think that shirley was looking at them too.

[terry2]

You need to balance the pack every charge. Unless you KNOW it was in good balance already and DO NOT fully charge it. And only do that a few times max.

Terry, what's the balancing current on the OverkillSolar BMS?

Steve

Only a tiny 80mA according to shirley, and only then if its a long way above the correct voltage. So its useless on a big pack. Esp if less than perfect/new. And already balanced by something else first. Hence he big list of warnings. But its got BT and nice graphics!

One more time for you.

It's programed by Overkill USA and you upload the latest settings from overkill site.

https://github.com/FurTrader/OverkillSolarBMS

[terry2]

This one looks interesting... https://github.com/Green-bms/SmartBMS

Terry, what's the balancing current on the OverkillSolar BMS?

Steve

I can't get in to the android app to see as I don't have the BMS

https://github.com/FurTrader/OverkillSolarBMS

[terry2]

All those like terry2 or fred005 who remain completely clueless are welcome to use their BMS. They work in EXACTLY the same way, and cannot be improved no matter how many add on adjustments and fancy graphics they pile on. And the fact that you are incapable of understanding that shows your ignorance. But I am trying to educate not stop you. I couldnt care less about your battery oryour risk if you dont.

80mA balance! Same as my laptop.

Its like trying to teach physics to my dog.

Citation needed.

[terry2]

So it's basically useless without a proper charger that can do 1A+ balance current? In other words, it'd take DAYS/WEEKS to balance a 210Ah pack which defeats it's purpose on a new build.

Steve

https://diysolarforum.com/threads/overk ... ent.11487/

That's all I can find out reading the link.

[Burgerman]

I read everything they have.
They never mention it because its super low. Like my laptop. How do I know?
Because they ALL are.
And because in the section in the massive user manual that still refuses to provide this data, theres a whole section explaining that you cant use b grade cells, or allow it to balance a new built pack. Etc. whatever like we all do, because its not capable of balancing them They even state themselves in the appendix near the end on the manual https://raw.githubusercontent.com/FurTr ... Manual.pdf
That they balance through TINY surface mount resistors. It shows a drawing with a ring around them! If you put 100ma never mind a full amp through those they would go into orbit.

Its useless. The manual is basically half right about a lot of things. And the rest is all excuses because the BMS is incapable. It might work out on a 10Ah pack. It even tells you that its not the BMS fault but that you didnt buy good enough cells!

Appendix C

And on another solar forum it says 50mA. Thats LESS (half) than my laptops battery...

That BMS is actually worse than the one in my laptop. It also begins balance at 3.4V which is one of the things I had changed on the PL8 because at that voltage you cannot balance. It puts the cells OUT of balance in some cases. So again. Its a lovely set of graphics and settings! If its just 1Ah out of balance it will take 1000 div by 50 to correct in hours. So thats an extra 20 hours!!! Marvelous. What if its 2Ah out on a new built pack? Thats TWO SOLID DAYS bouncing the high cells up to too high level. The 1A to 3A balance hobby chargers do that in 40 mins to 2 hours. And you realise that this ultra slow balance capability means holding all the full cells at top voltage and above, for many hours. Instead of a few minutes. Which they really dont like.

Of course that 20 or 40 hours doesent really happen because the charger will have already turned off. Unless you use a power supply and then YOU have to guess when to turn it off yourself. Never mind its a triumph of marketing over ignorance.

Do you know the best way to market these kinds of things? YouTube and any "credible" idiot - sorry "expert" by sending them one and bunging them a couple of k via paypal. I know as I used to do the same with websites. The less it looks like an ad the better it sells them.

[steves1977uk]

Found this... https://www.pp-rc.de/CHARGING-TECHNIC/A ... =2345V&p=6 Hefty price though!

It has 2A (2000mA) balance current though, so would put all those BMS's to shame!

Steve

[shirley_hkg]

This one looks interesting... https://github.com/Green-bms/SmartBMS

Terry, what's the balancing current on the OverkillSolar BMS?

Steve

I can't get in to the android app to see as I don't have the BMS

https://github.com/FurTrader/OverkillSolarBMS

[Burgerman]

But...

The PC software is crap...

And :

Process set-up – charging Pb cells
Settings for lead batteries are very similar as to the LiXX batteries, and because of that only the differences will be
described below.

Setting the balancer is not an option as far as lead batteries are concerned. Fast and Reflex modes have similar
advantages as in the case of LiXX batteries. The final charging voltage „Vc“ can be changed between 2,25V/cell
and 2,55V/cell. When the value reaches the one suggested an exclamation mark will be displayed (! Vc).

The charging process will end when the final charging voltage will be reached (1/5 of the set charging current or
100mA – the lowest charging current possible)

So lets say you are charging at 30A as I do all the time here. It will stop charging when the current reaches 1/5th of that 30A, so it will terminate the charge at SIX AMPS! And you wonder why I get frustrated with charger manufacturers. That will leave your battery suppsedly charged. But reality about 85 charged. It will stop charging after 20 mins CV. Instead of at 70mA and 8 hours of CV.

Worse. It does exactly the same on LiFePO4. But at a marginally better 1/10th charge current. So if we charge a 100Ah lead battery we want it to terminate at around 350thC. That would be Around 1/3rd of an amp. Or less. If we charge at the same 30A, will actually stop charging at 3A...

So unlike the PL8 it doesent let us choose the correct point on lead or LiFePO4. So they charge an insane amount and its worse!

So as per the PL8 and the older 1420 hyperion I would need to get involved in educating the manufactuer about batteries and have a sensible charge ago invented... And a way to set termination cuurrent. A third time!!!

[Arima]

What will be important there is if its possible to set a termination current in mA that is user defined. Rtaher than being some percentage of charge current. And if it can be set to balance only above 3.50V. And not terminate until balance ends. Those are the critical things. And that it doesent have 101 safety guards and traps to trip us up. It may be OK. I think that shirley was looking at them too.

I don't know...still looking for a detailed manual. A post on one of the rc forums said "I have had one for over a month. It’s a decent charger with a good price. The discharge current is only 30 watts per side. The termination voltage is adjustable from 4.30-4.40HV, and4.15-4.25 Lipo. It has a good balancing current of 1.5a".

[Burgerman]

The problem with that is it just shows that most people are ignorarant when it comes to chargers and batteries. Theres no such thing as a terminaion voltage. He is talking about the CV voltage. Yes that should always be adjustable. What we need to know is if you can specify a timer on the CV stage and specify if you can make that happen only if balance achieved and/or a current drop point where we can set to say its charged, so stop.

[Burgerman]

Shirleys drunk again. But posted a blue spec sheet.

That BMS which is the same as the Overkill Solar marketed version, lets your cells reach 3.75V plus or minus 0.03V and 1 second (so likely nearer 3.85V) before cutting off all charger power with its on/off overvoltage switch. Then it uses its totally feeble balancer of just 50 to 60mA to drag it down to 3.5V. (best of luck with that!) Then it adds the charger full power as it cant throttle it and does it all over again. And again. So its EXACTLY as I said. Only its even worse! At least the cheap nasty ones like the one on my dell laptop battery (all 3Ah of it) has a 100mA balancer!

[terry2]

This one looks interesting... https://github.com/Green-bms/SmartBMS

Terry, what's the balancing current on the OverkillSolar BMS?

Steve

I can't get in to the android app to see as I don't have the BMS

https://github.com/FurTrader/OverkillSolarBMS

That's not not the one with overkill settings flashed.

[terry2]

Shirleys drunk again. But posted a blue spec sheet.

That BMS which is the same as the Overkill Solar marketed version, lets your cells reach 3.75V plus or minus 0.03V and 1 second (so likely nearer 3.85V) before cutting off all charger power with its on/off overvoltage switch. Then it uses its totally feeble balancer of just 50 to 60mA to drag it down to 3.5V. (best of luck with that!) Then it adds the charger full power as it cant throttle it and does it all over again. And again. So its EXACTLY as I said. Only its even worse! At least the cheap nasty ones like the one on my dell laptop battery (all 3Ah of it) has a 100mA balancer!

Again since you're too lazy to do your own home work.

https://overkillsolar.com/support-downloads/

That's their own settings files which you flash to the BMS.
Nothing like above pic.

[Fred005]

Just to (try to) understand.
But, at first, I want to remember you that ...

I know what it is. I was sayiing there are NO lifepo4 replacements that are ever going to be reliable or worthwhile.

Many of us on here, including myself for a decade, have been using LiFePO4 for power. It can when done corectly give 10 years plus lifespan, and 4 to 5 times the range. But a lead brick replacement such as the ones you linked to wont allow any of that.

With these LiFePo4 batteries, as I wrote many time (but you maybe have to read and not only what you want, BM), I can hike with my 4 motors X8, for 8 to 10 hours depending of the area but ALWAYS in high moutain area.
Ok, I read you BM, with 230ah I'll be able to hike the double. My calculator is well working ...
But, explain me, how I can still charge around 210A in these 2 110ah batteries, after around 50 cycles completed WITHOUT and NEVER balancing these 2 LiFePo4 ....
It's completely the opposite of what I've been reading here.

For the moment, my own opinion, is, these "very bad LiFePi4", as you say BM, are not so very bad, and also, all what you and others are affirming about balancing/BMS and so is just ... How could I say ...

I've no doubt that the PL8 is ... WAS a good charger, but IT'S OVER. You know that I'm sure.
At the same time, I'v no doubt BMS is a good solution, even if maybe it's not the only one.
Next spring, when I'll get money to buy 8 230ah cells and BMS, I'll prove you, you have to change mind and, the most important, stop affirming bullshit.
Because, in my own case, you affirmed me tons of this wrong affirmations about my joystick place, about my PM settings, about center of balance of my X8 after saving 20kg with my actual LiFePo4, etc, etc, etc.
It's not you're idiot for sure, it's only because you are not reading all what people are writing, you are glued in your configurations and old ideas.

However this forum is an interesting one.

Have a good day, for me I'll try to hike more than 5km with 2 unbalanced LiFePo4 !!! Lol.

[LROBBINS]

Fred,

I read through that entire manual and did a search for balance current. Much of the manual is pretty sensible, but I found no mention whatsoever of balance current. If I recall correctly I had long ago looked at a pic of the board and saw that the resistors used for balance were very small SMD (at most 1/4 Watt, more likely 1/8 or 1/10) so the balance current is necessarily tiny. Hence their insistence that you manually top balance the cells (a good idea in any case). This may work out OK in a solar panel backup installation where continuous discharge rates are fairly low and fairly constant. It will not work well in a char with very high and variable discharge currents - with the high current, cell differences, e.g. internal resistance differences, will cause larger imbalances during discharge and this BMS will have an impossible time re-balancing them during charge.

[Fred005]

Fred,

I read through that entire manual and did a search for balance current. Much of the manual is pretty sensible, but I found no mention whatsoever of balance current. If I recall correctly I had long ago looked at a pic of the board and saw that the resistors used for balance were very small SMD (at most 1/4 Watt, more likely 1/8 or 1/10) so the balance current is necessarily tiny. Hence their insistence that you manually top balance the cells (a good idea in any case). This may work out OK in a solar panel backup installation where continuous discharge rates are fairly low and fairly constant. It will not work well in a char with very high and variable discharge currents - with the high current, cell differences, e.g. internal resistance differences, will cause larger imbalances during discharge and this BMS will have an impossible time re-balancing them during charge.

You're maybe right about "but I found no mention whatsoever of balance current".

But with my https://www.power-manutention.fr/batter ... -9418.html, wich never have been balanced, after 50 cycles completed, they still accept a total of 210A when each voltage of them is 10.8 volts, so nearly empty.

So I'm not so sure balancing is so important, otherwise it'll be impossible to charge my batteries with so much amps ....

[Burgerman]

But, explain me, how I can still charge around 210A in these 2 110ah batteries, after around 50 cycles completed WITHOUT and NEVER balancing these 2 LiFePo4 ....
It's completely the opposite of what I've been reading here.

No its not.You can 99.9% charge a lifepo4 Cell (or a bunch of them with inadeqyuate balance capability. For a lot of the time.
But as soon as a cell reaches 99.9% full that cell then shoots up from 3.4V to a really high point. In seconds, after charging for many hours at 3.xx volts. That massive sudden rise at the last 0.01% is the problem. You obviously still put back most of the charge. But you damage a cell or two every time you do it. OR worse you never get it fully balanced. This gets worse every charge. And then one day you suddennly stop as a low cell that you didnt know you had (caused by a high one preventing a full charge on the others) makes your chair stop unexpectedly.

Theres 3 things lithium ion cells hate. Which severely shortens lifespan. Being full. Or above around 3.5V. ESPECIALLY if overvoltage and for long periods.
Being empty or below around 3V which happens to some cells if they are not correctly balanced.
BEing discharged at a high rate. Which means a pack that is double the size is twice as good. As you are only pulling half the amps per Ah. It also lessens aveage depth of discharge so no cell gets low which they do not like.

But I am wasting my breath. You will get nowhere near the 2000 cyvles you expect. And maybe you will get a breakdown or failure due to damaged cell long before you expect. And maybe it will just stop in the middle of one of your hykes far sooner than you expect.

But again. I am not saying dont use a BMS just that you should be aware of the issues instead of being in denial and thinking its some ind of fight.

[Burgerman]

Shirleys drunk again. But posted a blue spec sheet.

That BMS which is the same as the Overkill Solar marketed version, lets your cells reach 3.75V plus or minus 0.03V and 1 second (so likely nearer 3.85V) before cutting off all charger power with its on/off overvoltage switch. Then it uses its totally feeble balancer of just 50 to 60mA to drag it down to 3.5V. (best of luck with that!) Then it adds the charger full power as it cant throttle it and does it all over again. And again. So its EXACTLY as I said. Only its even worse! At least the cheap nasty ones like the one on my dell laptop battery (all 3Ah of it) has a 100mA balancer!

Again since you're too lazy to do your own home work.

https://overkillsolar.com/support-downloads/

That's their own settings files which you flash to the BMS.
Nothing like above pic.

Again. Their BMS uses the very same minute surface mount resistors to try to balance. Anything more than 50mA will send them to heaven. You do not have any clue. And I read that pdf a long while ago. They dont tell you anywhere in it the balance current because it is embarassing for them. They just have 100 excuses about why it will only balance certain super high quality cells and only if YOU balance it properly yourself before you assemble the back. Its a sad joke. Again a triumph of marketing over ignorance