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Don't obsess over voltage, but us eggheads watch tail-current instead to determine when a "cell is charged to 100% full". The old rule for LFP - *any* charging voltage at 3.45v to 3.65v CV will charge a cell to full capacity. The only difference is time it needs to do so. So yes, voltage can...

I'll let you do your homework on what you eventually up with, but will emphasize this: Those tool chargers may be very simple or very smart. In either case, what they are expecting to see on their AC input, is a PSW or pure-sine-wave. So make sure that if you use a system that incorporates an...

The SEI layer is pretty thin on new cells coming from the factory - just enough to keep the battery from eating itself. It takes 4 or 5 cycles for the SEI layer to develop to it's nominal thickness, so there is a bit of headroom for non-perfection in regards to reasonable time, voltage, or tail...

I DIY'ed a suitcase out of two 100 watt panels, but of course took it to the next level: Hinged them on end so that they fold out like elongated wings. A few reasons for that: 1) Lower profile. Mine never blew over, but it made it harder to do so. A pain to fold out, but.... 2) That profile...

Here's the deal with Fluke: Unless you have an established high-accuracy voltage reference to compare to, when you take a Fluke home, you can more or less trust it. You can even use it to compare other multimeters to make sure they are just as good! But see what I'm saying - who 'ya gonna...

Note to lurkers about the last part of the table: 3.45v (13.8v) = end amps tail current = zero This does NOT mean you can sit at 3.45v CV (or 13.8v for a 12v system) forever! It can still be overcharged at that low voltage. Ie, just because you finally reach zero amps tail current at this...

OR - derate your cells rating by 20% if you are not planning to always charge to full, and not drop well down into the discharge knee. Problem solved.

Yeah, confused a little here too. I think what toms was warning about was the factor of time trying to achieve perfect balance, when spending too much time doing so is more harmful than having a bit of slop. I call it balance-addiction. Imaginary video: "So guys, it's been 4 days of balancing...

Why wait? I'm about to bring out a new line of night-time fresnel-lenses that you drape over your panels! Full moon events are especially good for harvesting. Just don't forget to remove the lenses before morning. Our warranty doesn't cover that. :) That's it! Lunar panels!

Ironically I can recommend a very expensive charger that could have helped prevent this for those who are using budget / unknown quality batts. A $180 10A charger? Am I crazy? If the Tecmate-Optimate TM275 Lithium 10A ampmatic charger saw this batt, here is what it would do: 1) Immediately...

DO NOT USE THAT CHART. Most are based on non-charge resting voltages, and are innacurate to boot. There is only one voltage listed that shows under charge. The chart thing is in another dedicated thread. Here, the bms values discussed are based upon CHARGE values for one thing. That chart...

That build brings a tear to my eye. Used to do the same thing, but stuffed them with pure-lead Odyssey agm's. Storing at full with LFP and a compromise? I take the more practical approach that I tell my neighbors to do with their lithium tools rather than shoot for a specific level: After a...

dih dah dit ! Balance Obsession: What this reasonable delta of 100mv or less, without worrying too much about it points out a problem that most are totally obsessed about achieving exact voltage parity when balancing. When that can mean squat from a practical standpoint. Example: You...

After being schooled by RCinFLA over in the Chins thread about what is actually inside an aluminum cased cell (open wraps at top - entire case is the singular seal, rather than individually sealed pouches) I offer up my best Monty Python Anne-Elk theory on Brontosaurus: "SNUG" containment...

I do like your recommendation to be more aggressive, because far too often those who buy batteries then cheap out on the back end with the wimpy charging. But batteries, especially FLA, aren't *that* dainty like eggshells if you don't get them back to 100% after 12 hours of non-use. Nobody...

Yeah, but sometimes it's so time-consuming. Glad you've got the backbone for it. Most don't. Those who started to tell me how to run my business, especially if they were non-owners, were kindly asked to start their own business to right all the perceived wrongs that I'm doing. :) I better...

Look beyond the marketing and ask these questions: Q: How is the ability to be taken down to 0 volts useful, when your inverter or other dc powered systems are going to start to fail at 11.7v ? A: This is only an advantage if you don't use any sort of low-voltage disconnect, and are driving dc...

@PeterBC - Thank YOU! You reminded me to look once again at the Marine HowTo and it solved a major sticking point for me, one of which was critical. https://marinehowto.com/lifepo4-batteries-on-boats/ You listed how he showed the "Parallel Step-Method Top Balance" in msg #8 - aka "PSMTB"...

Wow - so glad to see some taking cleaning your hardware seriously. It's been hard for me to convince others to do likewise to not only clean, but the importance of using No-Alox or Penetrox. Not gobbed on afterwards, but a *thin* coat on all connecting hardware before assembly. I like to...

Took a look at the controller and manual. It appears to be an slight upgrade from their older 7A SCC, but still appears to be the 1970's "hysteresis" type, where it simply cuts in and out between the high and low voltage and "ping pongs" on and off. At first it happens rapidly, then eventually...

I think so. He goes into that into more detail on the marinehowto site. Brings back memories. One could take a week's vacation and read the still active thread that started back around 2010.... 9 or 10 years ago, this was the first video I watched of his, long before "influencers" got paid...

That's great information. I might add that if you smell a "strange-perfume", that may indicate a leak. Once smelled, you'll never forget it. Just note that there's a difference between putting your nostril directly on the case, as compared to wondering why your garage smells like the...

I guess we've finally gone off the rails but this does bring back memories in the dark ages where the ops question could be changed to "Are there any Pb lead-acid batteries that just work?" The problem in most forum threads was defining work vs work-well, as in engineered for the application...

Actually the physics are well-known and have been for decades. Many of the improvements are not actually necessary, but improved manufacturing and distributing is. Many of these so-called improvements are actually nothing more than "investor-bait" for advanced LFP that never see the light of...

Sure! But treat it like a starter, the application it was designed for with the very thin plates where no single start should discharge more than 5 - 10% capacity. So, for this 80ah starter agm, if you are going to cycle it with light loads, draw no more than 8ah from them each cycle. You did...

My biggest was trying to manually "compensate" for a long run of thin cable's voltage drop. While my battery specs said the terminals wanted to see 14.4v CV, when I measured the cable prior to setup, I did a dc measurement with another battery and saw a little less than a whole volt drop at the...

@svetz You are completely right. And you got me fired up in a good way.. :) This project avoids the use of properly detecting the dv/dt signal from the cell(s) which demands a much higher current charge, like 0.5c or higher to do properly to avoid missed terminations. For that, we'd need...

I know what era you are coming from - my daily round trip through diyelectriccar and cruisersforum forums. All the while keeping an eye out for the application differences that might not apply so strictly to my general purpose sub-c application. An actual A123 engineer on another forum might...

How do you even stay in business like this? I mean allowing a cell to go up to 3.844v before tripping? And then allowing the user to see that with the app! Any googling shows that this is a bad thing. If that value is actually true, then at least don't provide the user with an app to see it...

Yep. For those actually living / working in wheelchairs, it is best to get *expert* advice from those who have have been dealing with the peculiarities of that application for a very long time, rather than here I'm afraid - be it it old-fashioned lead-acid, or LFP. Different applications...