Hi Slowhand, the drawback with using any software based system is virus attacks, and Linux/Unix/Apple are right at this moment the target for hackers and virus attacks. Microsoft has always been a target but at least there is a lot of companies building filter programs to detect any new one and remove them while Microsoft itself builds patches for known problem.... The Linux etc mobs have a lot of catch up to do.
This isn't an issue if the system is not connected to the web and the programming didn't ever come from the web, that's about the only way it will be virus free. Once it's connected to a computer that has been on the web how ever and the virus firewall collapses.
Of course the other issue is program glitches, fine for those who understand that stuff, I doubt you'll fid a lot of motorhomers or caravanners that do, add the first port of call, the auto sparky to the list and you have a system that can only be sorted by connecting it to the web..... do we add a go to line here, return to line 1 and reread
The alternative is a simple analog control system, simply for the owner to diagnose via a flow chart, no need for the rather expensive auto elect to learn how the systems works while you are paying him before he can start to look for the fault.
We have been perfecting such an anolog system as you have mentioned in your thread, minus the balancing boards as I see no point in trying to fix something that ain't broke using something that couldn't do the job required anyway.
Transfer balancing? There is a device called a Relativities that claims it can do just that, it works with 4 cell I series batteries as they stay balanced without anything added, but it doesn't seem to do the job intended on 8 cells in series systems (24v nom.) as they do have a cell run away issue if the terminal charging end voltage is set too high, but the analog system steps in and saves the cells from damage just as it's designed to do, stops the charging for a timed period and then resets and starts the cycle again. The fact is, if the cell to cell balancing system actually worked, while the charging was stopped some of the excess capacity from the high cells would be shifted to the low cells and the total of the 8 cells combined voltage would have the charger cut back the current before a cell reached the 3.6v threshold, we are yet to see this actually happen luckily the anology system is there in the background to save the day
If you really want to go the microprocessor route, check out this thread http://forums.aeva.asn.au/forums/pip404 ... c4332.html then read through Coulombs and Webers MX5 build thread to follow what was involved in building their BMS system, and these 2 guys are right up there on the clues and leaders in their profession.
T1 Terry
A person may fail many times, they only become a failure when they blame someone else John Burrows
Those who struggle to become a leader, rarely know a clear direction forward for anyone but themselves
If you were going down the full micro-processor / PLC / PC route I reckon it should control your whole rig.
A simple algorithm would control your chosen electrics / heaters / coolers / systems depending on how much power you have, what is going in, whats needed, whats more important to you, if you are on the move, relative temperature, time of day and history.
And it would be good!
But a pain in the arse to start with
Craig, I look that the charge % a few times a day of standing still, I set off my cell balancer as soon as I remember while driving, other than that, its pretty much set and forget.
Wobblybox on wheels
Pace Arrow. La de da, property in two continents..
Craig wrote:Hi Terry,
How much time is devoted to the safe operation of the lithium setup each day. Is it a set and forget type thing?
Yes, after about the first 2 weeks you stop fiddling with it, the system can and will take care of itself. The first time a new users fiddles with the cell balance they spend the next few days trying to undo the mess they made. The only ones that don't seem to suffer this problem are those who know virtually nothing about electrickery, they don't mess with the system and it works as designed from day 1 No doubt there are a few readers here nodding and going a little flushed in the face at the moment
I like to put all the monitoring gear where it can be easily viewed, if an alarm beeps you can see why quickly because that monitor will have a flashing display to tell you what it's not happy about. about the only issues we seem to have is with blown fuses due to circuit overload or circuit breakers de-rating their capacity due to poor internal contacts causing heat build up.
Here is an idea of what a few upgraded power boards look like
Evernew upgrade.jpg
Jayco lithium upgrade board layout.jpg
The techno stuff is behind the scenes in a black box tailor made to suit the equipment already in use so each one is a custom unit generally, but using a combination of well tried and proven gear and methods.
The only one I got caught out with was reusing the owners Bushwacker solar controller, it was not up to the task and failed to control the over all battery voltage. Unfortunately the owner was one of the electrickery illiterate and out in the boonies in the WA gold fields, but I managed to talk him through a quick fix via phone calls and email with photos and arrows till he could get to Perth to have a Dingo installed, then I had to talk a rather cock sure of himself auto sparking through how to wiring and program it so he didn't stuff it up. it was around a 30 min phone call at the sparkies expense while he rewired and reprogrammed it
T1 Terry
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A person may fail many times, they only become a failure when they blame someone else John Burrows
Those who struggle to become a leader, rarely know a clear direction forward for anyone but themselves
Ok, spent half the night at T1's link-
"If you really want to go the microprocessor route, check out this thread http://forums.aeva.asn.au/forums/pip404 ... c4332.html then read through Coulombs and Webers MX5 build thread to follow what was involved in building their BMS system, and these 2 guys are right up there on the clues and leaders in their profession."
Then the rest of the night on 100mph e-bikes and boats and too much coffee and I think my eyes are bleeding now.
Terry, you may know a lot about some things, but absolutely nothing about open source/linux and it seems computing in general,
Open source/linux is the safest, most reliable computing systems on the planet. Linux is used in more than 90% of major servers and scientific institutions on the planet, most military, NASA for its of planet systems, 99% of movies, video, graphics and the biggest audio producers on the planet. All of China is switching to open source as is India and any other sensible organisations and people. If you'd ever used open source and understand how computers work, you'd realise how far off the mark you are.
As for apple and Microsoft, if you want to use last century expensive useless junk systems, which you never own, have no control off and every bit of your data belongs to microsoft and apple. Whilst being available to every business and hacker on the planet, then stick with them. They are so useless and vulnerable it's a joke, whilst a proper set up linux box is hack and virus proof in every way and if someone does try to attack you, you are capable of responding is such a way as to render their windows and apple systems dead. Cloud storage is another massive con, as soon as you put your data onto the cloud, it belongs to the server owner and not you, if the cloud server is microsoft and crashes you lose everything. If someone could crash or attack my system, they would get nothing as linux doesn't work like windows and sensible users always have their data stored outside the operating system, not part of it like win and apple.
It's understandable most stick with what they know, especially those who just want to do the average computing online browsing thing, but it costs them a lot of money and time to use last century swiss cheese security and bloated constantly failing systems.
But if if you want economic and computing freedom, ease of use, security, 21st century state of the art and every form of software you've ever need free, then open source is the only option. In the years Ive used open source never had an attack virus or anything security problem, nor a crash. Can customise my system to my hearts content, write and install programs. It's that simple and all the code is available and easy to use, unlike microsoft. By the way, apple system are linux based, they have installed code blocks and software locks to stop fixing their junk fault ridden systems without paying them.
Linux/open source is only for those who want control over their computing lives and like to be at the cutting edge of computing development. I use the same based multimedia programs as those who made lord of the Rings and it is within a custom built multi media system called Ubuntu studio, one of many brilliant linux media systems. Nor would I try to make anyone change to open source, unless they wanted real security and control over their computing lives. Most are happy as they are and that's fine, it makes the economic world go round and round, but never forward.
A programmable BMS/cell balancing system is very simple to use, not quantum physics. Just rational logical and ease of use. Why do you need to go online to use an external BMS system and if you did, and were using windows, you are open to every kind of attack virus or glitch. With open source you fix your own glitches if any, or someone will provide a patch within 24 hours, like bloat ware which takes years and never if it will actually make your system safe.
Analogue is fine for some things, flow charts are last century and time consuming. Never met an auto electrician who has a clue about lifepo4 or computing, even though most of the vehicle computing is open source based and just about every electronic appliance is is open source bases, not microsoft or apple.
The link you provide revolves around a system not designed for lifepo4, so is irrelevant in every way and not representative. I have already said there are virtually no BMS or charge controllers which are designed for lifepo4, from what I'm told from manufacturers, battery suppliers want redundancy within their systems and using close to LA parameters and non balancing BMS, they have their 5-7 year redundancy. Why are you trying to deny what I posted and make out I've posted something else.
As for the charge controllers I've been looking at, they have confirmed it is only microsoft based and designed for USA standards export, that's why they do that. The USA is the only backer of microsoft and apple, everyone else is moving to this century systems including governments and especially logical thinking people who like to keep up.
The aim is to have a control/charge system which will look after your lifepo4 pack safely and not having to constantly fiddling with it to get it balanced and safe. Plus being able to customise it to your own requirements, that's my aim. Most are waiting for a drop lifepo4 battery pack, but like LA and all consumer goods of today, they will have redundancy built in. If a BMS system comes along which does everything for you and is user adjustable and repairable, then all current problems are overcome. That's what m aiming for, I'm lazy, don't want to go near my lifepo4 pack and want to be able to remotely monitor and adjust it if necessary.
I have to say most of your post is illogical, why would you set voltage limits high, to create a runaway situation. Digital switching is just as reliable as analogue, in fact more reliable because you have less things to go wrong and can have backups built in to most of your system. What I'm playing with, is both analogue and digital, when finished will have a number of fail safe backups, both analogue and digital.
Don't get me wrong, I was a dedicated analogue person until I watched my kids for 8-10 years playing with open source digital systems and then lipo and lifepo4. So decided to step into this century and haven't looked back. Sadly the maths and technical jargon leave me and most for dead, so stick with plain English logic and rationale, not denial or misguided false information about state of the art approaches.
As explained in my post the BMS I'm using cuts off charge at the set upper voltage pack limits, allowing the balancers to do their work if needed. Yet you seem to be denying that for some reason and putting forward illogical and false premises.
Your photo;s show a large array, the one I'm working with has one programmable display and two programmable display backup switching relays, which can be timed. That's, it everything else is in the box and consists of balancing remotes and current sensor, no need for anything else.
Find it very offensive when some cynically laugh at what others post and try to deride what they say with ridiculous uninformed claims. as you have done in this post to me. You may have a great deal of knowledge, but it's useless if not understandable and contradictory to viewable fact. All information is good, even if it is misguided, misunderstood or wrong. It at least opens doors to understanding which may not be available otherwise and efforts to suppress that with ridicule or derision, is counter productive.
OK, I can see that this thread might get out of hand shortly.
Perhaps a few "in my opinion" statements rather than "I'm right and you're wrong" might be in order?
Bob I think T1 was simply getting the point across that as, like you say, Linux in all it's flavours, is safe (at present) and used by the big players it therefore becomes the target of the month for hacking attempts.
Imagine if those hackers find & publish how to hack it?
Can we please concentrate on playing the ball and not the man?
All info is good and opinions welcome .... even differing ones.
Remember....... a lot of people are reading your posts & personalities become evident by words written.........
In a word ... COOLIT!!
******************* BruceS
Mannum, SA
********************
The utopian digital BMS still requires analog relays to do the actual current switching. So why not a digital BMS that senses voltages (an analog function) and simply activates the relays? No more than that. Oh, and has a display to tell the user something about what is going on (again, an analog function).
That's exactly my system, grounded on T1 Terry's help. I described it in detail in an earlier post (page 10, I believe). I cannot see that we would want anything more complex, unless it was a whole-of-RV control and management system such as in some houses. But the maintenance and trouble-shooting of those systems must be a nightmare.
I can see a distinct advantage in a system that simply shuts off when done. If it is organised to do so at cell level then even better. No relays etc, just a full battery, ans a charger that kicks back on as required.
Wobblybox on wheels
Pace Arrow. La de da, property in two continents..
luckily the anology system is there in the background to save the day 
Ok, spent half the night at T1's link-
