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Steve_S
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# Posted: 21 Jun 2024 03:23pm
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Of course they do but there are MANY Lithium Based chemistries. Some safer (LFP) than others, NCM/NCA have higher energy density (why they go into EVs) in a smaller format.
Having Lithium etc in them is NOT a problem. Having a GOOD Battery management System IS CRITICAL as well as a proper Smart Charger. Sadly with Cheap E-Bikes etc those two criticals may not be up to snuff, often aren't.
Even Meanwell Power Supplies are CC/CV but they do not respect the resistance to lower amperage after the threshold (Endamps Tailcurrent value). Yet to have a charger than can sense resistance & reduce current appropriately and terminate charge at X Current being taken, costs a "BIT" more and most proper e-bikes etc come with those.
Simply put, the "Cheapsters" will use a LED Light Ballast / Powersupply that can be set to X Voltage & Y Current and that's it, they leave the rappy BMS to cutoff the charging which is WRONG on many levels... it is NOT the BMS' job to do that.
ALL Lithium Based Batteries are CC/CV and if the proper tailcurrents for the specific chemistry are observed, you'll never have issues unless there is actual physical damage.
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ICC
Member
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# Posted: 21 Jun 2024 03:30pm
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Yes, gasoline vehicle fires are much more prevalent.
Also, there are many cheaply and poorly made e-bikes and e-scooters available. And as Steve mentioned the LFP chemistry is very safe. They don't burst into flames or explode. There are other lithium chemistries that can cause fires. Sometimes that can be the fault of cheaply made cells. Sometimes physical damage. Sometime cheaply made chargers or control boards (BMS).
FWIW, the other types of lithium cells are popular for some uses because they are more energy dense; more AH capacity per volume/weight. There are many types of lithium based batteries and different voltages so that too could be a problem if people plug in the wrong charger type.
As with any electric equipment, only buying or using equipment that has UL or ETL approval can go a long way in being safe
.
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paulz
Member
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# Posted: 21 Jun 2024 04:00pm
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On a personal level, good to hear my LfP stuff around the cabin is safe. And coincidentally, my truck failed smog last week, maybe something electric down the road. Retest next Monday. And the wife wants an electric wheelchair. She can wait till I’m gone, still a year or two of push left in me.
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Steve_S
Member
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# Posted: 21 Jun 2024 04:53pm - Edited by: Steve_S
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Unfortunately, even with UL/CSA/ETL and all the other certifications, they are not guarantees, but an assurance that these comply to basic set safety standards.
On the Good side of the E-Bike & personal transport side.
- Many of the companies are indeed getting the certifications & doing things like potting the cells and better "pack" BMS's with added safety features. A few even have a link in their main app to see the pack state internally.
- Another is the "connectors" issue being addressed so you can't intermix chargers*. As noted by ICC above, the chemistries & voltages are all different and not interchangeable. The "BIG Name" E-Bike companies etc have addressed that, but it's the myriad of smaller ones & imports that have to deal with it too.
* The "connector" issue also came up very quickly with the various Residential Power Packs & "Bluetti type stuff" but more as there are so many on the market now. There were a few incidents that raised that flag quickly.
LFP itself won't catch fire & go "thermal" like the other chemistries. It can vent off gasses that can combust but once that's burnt, that's it, it's gone. Getting it to vent does take some serious doing too.
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paulz
Member
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# Posted: 21 Jun 2024 07:31pm
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I run my yard cam of this, doesn’t say what it is but weighs nothing. To charge I just jump it to my Valence bank overnight. Those, I figure, are about as safe as they get being medical. Other than that, just chainsaw/tool bats, typical stuff with matching chargers.
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Steve_S
Member
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# Posted: 21 Jun 2024 10:18pm
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Gee wiz, no specs or anything on all that labeling ? That's precious /s
Those Valence batteries really are good from all that I have seen. Sure few have issues but .. used etc... Darn shame that company doesn't go retail with various sized batteries - similar quality etc...
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ICC
Member
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# Posted: 21 Jun 2024 11:34pm
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Quoting: Steve_S Gee wiz, no specs or anything on all that labeling
A reverse image search with Google found this.....
https://www.small-cabin.com/forum/1_8145_10.html
And this... (40 ah version...)
http://dkdhitech.com/12v-40ah-lithium-ion-battery-p477481.html
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paulz
Member
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# Posted: 22 Jun 2024 01:40am
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Thanks Izzy. Guess I looked it up when I got it, new but from a private party. This one is blank on the back side, not even that 800 number.
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paulz
Member
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# Posted: 25 Jun 2024 05:58pm
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Sorry, can’t find the other thread on Lfp deals. My friend got 12 years out of his 6v flas! Now he wants to get LFPs and a new controller (his old one is a Tracy?).
He found these batts on Amazon. Anyone familiar? I advised him on a Victron CC based on what you guys have said.
https://www.amazon.com/Solorage-LiFePO4-Lithium-Lifetime-Trolling/dp/B0CL4TH1FM/ref=s r_1_5?crid=3577UFHMH18WQ&dib=eyJ2IjoiMSJ9.F0ehGdID0_0hGz3R-C-8ylI0nU0GcErSPKjEfXFVSb2 ESSkIGn_s2RnWxIDYt7AVZe3TuKqhCX0cNbKstFjdEPh7zb03d77JxoLtc7_K6Ac5ZK8utyFQJxGhNFGm3_c2 D68N1Rakky7tfFXbJdl77iMTxEbgXRd679vX2hxGh2fwlsZhOqCwEZzDF90g3MFICvTtO7HJqyPTHrL8eZewM N8BORXLLX4LlNOzjMGzw7M.1LrnoB6tx7xn5jZumJaA1DQnD6xuDkYH4S6ae_EntfY&dib_tag=smacab-20&keyword s=lifep04%2Bbattery%2B100ah%2B12v&qid=1719331858&sprefix=lifep04%2Bbattery%2B100ah%2B 12v%2Caps%2C210&sr=8-5&th=1
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ICC
Member
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# Posted: 25 Jun 2024 06:46pm
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I looked at the Amazon offerings and decided it was a crapshoot. Many good reviews and some bad. Many different brand names, most unheard of, especially in the lower $ ranges. I believe you cannot go wrong with a name like SOK which has received excellent praise from Will Prowse / DIY solar. That was why I chose an SOK. Their customer service has been great for me the one time I had questions soon after buying it. https://www.us.sokbattery.com/
Definitely Victron for a new CC.
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paulz
Member
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# Posted: 25 Jun 2024 07:40pm
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Yeah I mentioned you had recommended SOK. He has a couple off grid guys with cabins where he’s at, we’ll see. I’m just a third wheel here.
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paulz
Member
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# Posted: 29 Jun 2024 09:12pm
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Well he ended up buying 3 of these. 644$ out the door.
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Steve_S
Member
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# Posted: 29 Jun 2024 10:47pm
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Never heard of them. Just searched Amazon upside down for "Feence" " Elefast" and various combos with LiFePo4 etc etc ... nothing... I'd say I hear dice rolling in a cup.
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paulz
Member
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# Posted: 30 Jun 2024 01:37am
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Quoting: Steve_S ... I'd say I hear dice rolling in a cup.
Could be, we”ll see. He must have gotten a recommendation, they’re not the cheapies he found earlier.
The other thing he wondered about was using a regular car FLA charger on them (in non solar times I guess). I think things like bulk, flood, equalization and general over voltage charging don’t make that a good idea? Never tried it myself. I know my charge controller has separate settings for fla and Lfp, never checked the differences.
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ICC
Member
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# Posted: 30 Jun 2024 01:48am
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Huge differences. Many FLA chargers, both AC plug in ones and solar charge controllers have an automatic periodic equalization. Good way to kill any lithium based battery.
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Steve_S
Member
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# Posted: 30 Jun 2024 09:53am - Edited by: Steve_S
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I wonder what effect an LFP BMS would have if/when the BMS cuts off charging while a Car Battery charger is pushing at it. I'd hope the charger would just stop as well but... and then what if the BMS re-enables charge ?
I don't have any 12V LFP Batteries but I do have a Smart Car Battery Charger (not voltage adjustable) and looking at its settings, I wouldn't use it on LFP.
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paulz
Member
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# Posted: 30 Jun 2024 01:58pm
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Quoting: ICC Many FLA chargers, both AC plug in ones and solar charge controllers have an automatic periodic equalization. Good way to kill any lithium based battery.
That rings a bell, and I just checked my CC, an old Epever with no Lfp settings (have to use ‘User’ setting and enter your own parameters). I have equalization set to zero.
But with a bit of online ‘learning’ this came up.
https://www.jackery.com/blogs/knowledge/ultimate-guide-to-lifepo4-voltage-chart#:~:te xt=The%20float%20voltage%20of%20a,equalized%20voltage%20is%2014.6V.
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ICC
Member
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# Posted: 30 Jun 2024 02:51pm - Edited by: ICC
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I believe the article should explicitly point out that LFP batteries do not need equalization at all. BUT, if the charger one is using does not have the ability to disable or turn off equalization then the equalization voltage should be set to NO HIGHER than the bulk charge voltage and perhaps as low as the float voltage. Plus the EQ time should be set as short as possible. With those settings if an EQ does start, no harm will be done.
The LFP setting on a good charger, like the present Victron chargers, totally disables EQ. There are others that do that too. Read spec sheets.
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gcrank1
Member
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# Posted: 30 Jun 2024 04:43pm - Edited by: gcrank1
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I agree Izzy, and would opt for the 'float' voltage setting (if you can set it) And if the EQ can't be disabled totally.
Something I wonder about with relatively inexpensive charge controllers is if they do a power reset (or flake out) do they default back to having EQ enabled? I suspect they do and I don't like that.
I disagree with the 14.6v for bulk but for rare occasions or when you really Need a fast charge; ie, that seems to be a commonly mentioned 'max' charge rate for LFP and imo too high. As Ive mentioned before I have my charge unit set at 14.0 for normal recharges
and run the bats to 13.6-13.8. They still settle out at 13.3 or if a bit more they quickly go to 13.3, which is the high end of the 'working voltage' of 12v LFP.
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paulz
Member
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# Posted: 30 Jun 2024 05:58pm - Edited by: paulz
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Yep sounds right. Well I found this charger in my pile, never use it, should work.
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Steve_S
Member
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# Posted: 30 Jun 2024 07:44pm
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You had better check the voltages before attaching that charger to anything. It says "Lithium" but many chemistries & voltages apply to the generic term. "OOpsie Avoidance".
I looked at that guide too... goodness me.
ICC & gcrank1 said it all.
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paulz
Member
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# Posted: 30 Jun 2024 09:35pm
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It measures a bit over 30vdc. Don’t know where it came from, been around since before my hospitalization last year. Searching the numbers don’t say much, from a mobility scooter maybe?
Anyway looks like an anchor weight now. Was going to give it to my friend but I better not
Thanks for the heads up.
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gcrank1
Member
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# Posted: 30 Jun 2024 11:13pm - Edited by: gcrank1
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I checked my book for my smart charger (w/o a Lith setting) and the Gel Bats setting doesnt do an EQ and the voltage looks ok if I keep my eye on the tail end. Then I hooked it up and used my DMM to verify the read-out on the charger; it matched decent enough to keep track.
Of course the company said 'Don't do it', but I doubt their csr has any real idea of the parameters for LFP....just a cya for them to say No.
Looks like the things to watch out for is the voltage on initial charging so it doesn't spike enough to trip the BMS then monitor while charging to see what it settles into charging at. For me the same 13.6-13.8ish at battery as a target would be my shut down.
Anybody see anything red flagging this?
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paulz
Member
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# Posted: 30 Jun 2024 11:51pm
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That’s neat, non of my chargers have a Gel setting that I recall. Good thing we have those Meanwells, just set and forget.
Will yours work? Well I’m the last guy to ask.
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gcrank1
Member
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# Posted: 1 Jul 2024 01:40am
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Meanwell is my go-to but after Steve's input and recommendations I have become bolder.....and trying not to be foolish.
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Steve_S
Member
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# Posted: 1 Jul 2024 10:56am
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Quoting: gcrank1 but after Steve's input and recommendations I have become bolder.
Roh Ohhhh what did I do now ?
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gcrank1
Member
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# Posted: 1 Jul 2024 07:03pm
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You da man, Steve, you da man; when you speak we should listen 
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Steve_S
Member
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# Posted: 2 Jul 2024 02:21pm
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Ohh my. I just share what I have Learned, Experienced & Observed over the years. A Partially Eidetic Memory helps with retaining it (but that comes with consequences too).
Also the fact that have a curiosity to know things by pushing stuff to limits - like my Thrash Testing that made a few cringe... Left-over from a former life where "knowing" where/when things will fail (real-world not theoretical).
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paulz
Member
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# Posted: 5 Jul 2024 04:07am - Edited by: paulz
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My pal who’s waiting for his new lifepo4s says to me “they can’t be used for starter motors”. Well yeah, that’s why cars don’t have them.. Got me wondering, what happens with excessive CCAs? I don’t have any big DC stuff to try and run, but the other morning I hooked my planer up to my bank, through the inverter. Stuck a board in there and it quit, wife said there was a load beep inside. Inverter powered itself back up but by then I had it hooked to the generator instead. Bank seems ok now, thank goodness.
So what happened. Did the inverter draw too much from the LFPs? It worked fine off the genny.
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Steve_S
Member
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# Posted: 5 Jul 2024 11:15am
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Two possibilties.
1) The Battery BMS cutoff. Will happen if too many Amps are demanded
2) Inverter could have read a Low Volt (when big surge hits there is a short voltage sag) and cut off.
Also if Battery was low to start with and major surge demand hits it and drops the voltage too low the BMS can also cutoff. There is usually a built in delay in the BMS to handle such cases. All depends on the BMS.
A Planer is a good tool to see what happens.
- It starts (without a load) but still has a "reasonable" start surge (like any motor) but nothing drastic.
- Stick a piece of lumber in it & load it and watch the Amps Drawn go up & batt voltage go down (there is always some sag & is normal)
- The harder the planer has to work the more noticeable... Compare with a piece of nice soft Pine and then a piece of nice hard maple. Oh Boi ! what a difference.
Same situation applies to any Heavy Motor devices like a Well Pump or Air Compressor. Starting an Air Compressor with 0 pressure is easy peasy and no stress and minimal surge demand. But once you have say 75PSI (load to push against) and want to push it to 125PSI watch the Amps Drawn climb and the voltage sag on the batteries. Harder the work = more sag (to a point)
Sorry I know it is obvious but who knows, who is reading this and what they know or don't.
Assuming the Planer is a "regular" 120VAC shop tool, it's likely rated at 15A or 1800W and likely takes a 17.5A +/- (2100W) momentary Surge (not unusual).
LFP is not ideal for replacing a "Car Starter battery". There are "some" Lithium Starter Batteries out there but from what I have been they are NCA/NCM Chemistry. Dunno much about them, other than I would not put one in my truck. (-35C to +40C Temp Zone)
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