Yes each cell still at 3.461Just keep in mind you need to monitor at the cell level.
Do I really need a bms? If I can monitor my batteries manually? That is by ensuring I don't discharge below 12v and don't overcharge above 13.8v? Do a top voltage balance say once a month?
Can you give us the detail of how you are doing that?now.
I do have a $3 alarm if any cell deviates or total voltage leaves my range.
oh for sure dont get inline, but do post the pictures when you stuff burns to the ground..Oh yeah I’ve definitely heard. Think it’s the 11th commandment now. Even my mom knowS it’s absolutely necessary and she has only ever used disposable AA.
Even tho I’ve been running without on multi banks without for years now.
I do have a $3 alarm if any cell deviates or total voltage leaves my range.
I didn’t say it’s a bad idea just saying it’s called a battery monitor system which there others ways to accomplish this that doesn’t say BMS but still does same thing.
You could literally hire someone to monitor for you with couple basic tools.
Advantage of BMS(as it’s preached) is it limits your involvement while putting all the weight on one thing to control the show.
It’s always the goal to minimize labor cost, I’ve just always played more fundamental role of various projects I do to for deeper understanding that helps with future decisions.
But yes I’ll get in line and say BMS is absolutely necessary. Yes yes yes don’t think just do
I guess it depends on how much you spent on your cells, and how much time you have on your hands to manually watch over them.
And if they are a cobalt-based chemistry which is at higher risk of going into thermal runaway, maybe you're a fireman too?
I guess if you're going to be physically sitting in front of your cell monitor, every single time you charge and discharge your cells, at any rate, the ENTIRE time, then you could probably get by without a BMS.
However, if you intend to charge or discharge, and even step out of the room for coffee (there's multiple stories on here where people stepped out for a drink, and overcharged their cells while they were gone), then you should have a BMS monitoring your batteries for you.
I just don't understand why anybody wouldn't use one now, there are MANY great units available for under $100, which is normally less than the cost of a single cell. It might work, until it doesn't, and the consequences of an overcharged cell can be catastrophic.
well you can pay for a BMS... or pay for your personal value per hourDo I really need a bms? If I can monitor my batteries manually? That is by ensuring I don't discharge below 12v and don't overcharge above 13.8v? Do a top voltage balance say once a month?
The DIY crowd generally isn't interested in having their entire project ruined, or potential house / RV fire. I find it odd that somebody would use super high-tech modern lithium batteries, and not be willing to use the same high-tech monitoring systems that they require. To use a car analogy, this is like buying a 2022 Corvette, and saying that you don't trust the computer, so you put a carburetor back on it.Like I said I didn’t say bad idea but..
The amount of people running no BMS vs ones with issues is very small percentage, can something go wrong of course and this is also true of BMS units being sold so when or if it fails don’t come crying to manufacture.
Level of safety and ways to minimize risks are always a factor.
I’m not attempting to change anyone’s mind as that’s nearly impossible.
BMS can fault and will not for everyone but a percentage as with other methods.
I guess what I’m saying is people are obsessed with automation and tend to focus on that process and it’s with everything, accounting for 50% of product advertising by word of month by consumer.
Does automatic processes make life easier sure, it’s not like I’d like to continue to tweak my carburetor car all the time for it to run correctly vs my fuel injection get in go car but I do understand how to make that happen which is just another method from getting from A-B
We use airbags etc but helmet could be better in car why since professional drivers sure do,along with full frame roll cages, wouldn’t that be safer? They seem to think so and numbers clearly show it,but we use a different process instead. Even tho deaths using that equipment is far safer and hard to argue.
I have no self interest either way and just thought a DIY crowd were more open to options outside of norm.
Just out of curiosity, how would your system handle a failing, low voltage cell if you weren't right on top of it? ALL cells WILL eventually fail, 100% of the time, it's just a matter of when it happens.Bottom line I wouldn’t recommend my process, especially to people new to LFP chemistry.
While many utilizing this technology is driving money towards better product and more competitive market getting the rest including me fully on board with idea of BMS is only way to go.
I’m sure if I was having issues it would drive me to other monitoring options.
My system is away from house in temperature controlled environment with remote alarms that if I had neighbors would wake them up and operate in window far away from edge it will be difficult to fall off.
It’s not really time consuming but I do check systems during the day probably more than some.
Going by internet and my experience with operating cells most push them to rated numbers so one guy results of battery life/issues could be totally different from another, just to many variables to account for.
One of the great features of internet is looking at people who come up with different ideas on how to do something, seeing or hearing of results that DIY crowd has done to fix or solve problems.
Long live the BMS as I’m sure I’m just late to the party.
You all win I surrender so no more rambling from me or car analogies. Closed.
Just out of curiosity, how would your system handle a failing, low voltage cell if you weren't right on top of it? ALL cells WILL eventually fail, 100% of the time, it's just a matter of when it happens.
One cell starts to dip voltage, your pack appears to have a lower voltage than it "should" be, and now your charger is trying to put 14.4 volts on a 3S pack, which overcharges the remaining cells to 4.8v each. Now instead of a battery, you have a balloon (and hopefully not worse), all in the name of saving a fraction of a percentage of the total battery cost.
I just can't see a single reason to justify not having a BMS. I understand that you feel your situation is unique, and it very well may be, but I wouldn't suggest that ANYBODY try and build an unmonitored lithium pack.