LiFePo4 battery users

[rvpopeye]

Young Will checks out a new formula( lithium titanate)

[TWIH]

Young Will checks out a new formula( lithium titanate)

Will’s tear downs are epic, I look forward to watching each one he does.  

I have a couple thoughts about lithium vs agm/fla.  One of the issues I have had with battery choices in a minivan is that there’s only room for a single 100 to 160 watt flat mounted panel on the roof with the use of either a dc to dc charger or a simple ACR alternator charge system.  

Since lithium is happy to not be fully charged and my proposed van driving/alternator recharge habits will be low (30 minutes daily or so) and a single flat mounted panel can’t supply more than say 20 amp hours a day (if even that), I couldn’t keep an fla/agm battery full enough to allow it a long life.  Lithium wouldn’t care.  Thus for someone like me, lithium would make sense, as long as I could afford the up front equipment costs.  Yes, one can get by with golf cart batteries for years, yet lithium sure seems like the way of the future.

[justjim]

In the short term not having to be fully charged daily is a advantage of lithium. In the long term you still have to replace the power you take out or just like any other battery, a lithium battery will simply become discharged to the point of not being able to meet your needs. Always be able to replace the power you take out daily and it is not as big of a advantage.

[Scott7022]

From the beginning it’s a system wide approach. Ok I’ll get off the pulpit; having typed that no less than fifty times.

Lithium iron phosphate is not new tech. Even for Vanlife. Technomad (cell service fame) did it years ago when it was bleeding edge. Now it’s almost Walmart tech.

Alternator charging is not the best method. Will actually doesn’t recommend it. Check out Sternwake’s thread on his monster alternator. Read, observe, bow at the awesomeness and then go look at your little AC Delco. Yes Miranda, it’s like the munkins playing basketball against the Pistons. Or alternatively go look at the crazy car audio mad scientist, link I provided on another thread, and his quad 380 Mechman alternator set up. That’s 800 bucks times four with the added expense of engineering a bracket that is plumb and provides adequate cooling. So SMB is five large with cable and power out of the gate.

Now this stupidness is to feed big power to push massive drivers to create pressure in a truck. Winning sound pressure level competitions. Now as stupid as this endeavor may seem to many of us. This is making and storing huge power. Can’t take away from that. The application we might think ain’t right but...

So an ACR isn’t really the way to go. It is cheap and set/forget simple. But neither the battery or the alternator is happy. A B2B is the preferred method. Allows you to control the voltage better and not trip your BMS cut out. Make sure it is wired into your ignition circuit. Otherwise you’ll hook up a battery charger to your starter battery and the B2B will sense 14.3 volts and start charging your house at 30 amps from your charger and start battery. If you’re using a ten amp charger then the additional 20 comes from the engine battery. For a while anyway.

Wired into ignition circuit then it doesn’t turn on till the engine does.

I think the application gold zone is the freedom of charge metric. Not everyone is sitting out under the desert sun. Yes in an ideal world take and put should be balanced. But who lives there? Lithium will run a fridge till almost 90% empty. A lead acid won’t. The voltage will dip below fridge levels well before that. A month of the battery cycling lower and lower isn’t an issue:
For example. Day one 100% happy campfire and boat drinks day.

Day two. Drawn down to 70% filled to 85%

Day three down to 63% filled to 71%

Day four down to 65% filled to 75%

Day twenty five down to 25% filled to 30%.

Ok sun harvesting isn’t cutting it and so an hour into town for beer is 30 amps and an hour back another 30. So if you had a 120 amp/hr lithium. Light charging, less than .5c, 60 amps or fifty percent, is gathered from the beer run. Add that to your remaining 30% and you’re back at ninety percent.

Yes this is simplistic and easy math. There are losses and efficiency issues and the like. But the overall idea is correct. The battery will last 3000 to 5000 cycles depending on the chemistry. You don’t hurt it. It is a happy battery. It never hit 20% discharge, it wasn’t charged hard.

Lithium’s don’t like being fully charged. Part of the old tech bias people need to forget. Ideally 100% down to 80% and recharged to 95%. Next 75% back to 90%, 70% to 85%, 65% 80%., 60% 75%. Then car trip or great sun day and put it back close to 100%. Sitting at 100 percent doesn’t make it happy. What many miss is hitting a 120 amp/Hr battery with 120 amps of charging current is actually more damaging than not letting it get to 100%. A 1C charge compared to a .5C charge to 96%.

An over-paneled roof, added to an alternator, without any control, could reach a high C charge rate.

Example:
Billy adds a bunch of solar, knowing he has a great MPPT charge controller he series/parallels his panels to make up for inefficiencies/partial shading and is pushing 70 amps. This more than runs his daily use appliances and trickle charges the battery. So his 100amp BB sits around 96% during the day and drops to 85% overnight and gets charged back to 100% before the induction coffee gets made. On Tuesday morning he makes coffee and while enjoying it gets bitten by a diamond back. It’s 10 am. He jumps in the truck and fires it up, tossing it into gear and doing a Blanch style exit from yarc camp. Cooler air pushes around his hot solar panels, and the charge increases. A cold alternator charges the house battery and the B2B pushes 50amps into the 100amp/hr battle born lithium. 70amps usual from solar but, over-paneled and cold say 73 plus 50 and we are making 123 amps. Over 1C and yes it will take it, get hot and the BMS will cut off before serious damage is done. Other factors could limit the current as well. But Billy DIY’d his system used SOK or “Something cheaper” and didn’t do X or Y to limit the current...

He went with bring it back to 100% as often as possible. As his design goal or idea. Perhaps a better way to look at it, as a design idea, is keep it in an 80 to 95% state of charge bandwidth. This limits the chance of you pushing to much at the battery in a oh shit I wasn’t thinking moment.

Sure if you are having a professional like Jim or others design your system then you can get closer to the edges. You have professionals thinking for you and designing a system that takes all this into account in a system wide design ideal.

But for the Billy’s of the world. It’s lithium it will make voltage to drive any 12 volt appliance down to a 22% discharge state. So long as you stay above 20% and Below98% and keep your charging amperage below .5C your batteries will be happy and last a good long time. Sure you can charge at 1C but you shouldn’t charge above 1C. So take that into account. Above 1C is harder on the battery than sitting for a year fluctuating between 30% and 70% state of charge. It’s lithium!


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[rvpopeye]

ZZZZZZZZZZZZZZZZZZZZZZZZZZ

Just jump starting this thread.
 I just read it all.  

Who is using LiFePo4 these days ?
Whatchya runnin fer gear?
Happy happy joy joy or ?
Any observations for those looking ?


I've seen some really good prices here and there.....

[Cavinaar]

ZZZZZZZZZZZZZZZZZZZZZZZZZZ

Just jump starting this thread.
 I just read it all.  

Who is using LiFePo4 these days ?
Whatchya runnin fer gear?
Happy happy joy joy or ?
Any observations for those looking ?


I've seen some really good prices here and there.....

Using LifePo4 myself.  Pretty happy with it so far.

  As for "full charge", according to LiTime (formerly AmpereTime) 13.3 volts is considered 'full', though their manual says to set max charge at 14.4.  Left alone after charging to 14.4, the battery will 'settle' down to 13.3.

  From personal experience I have seen that in use it will sit at 13.3 for a bit, then drop to 13.2 and sit at that for a good long time.  I use my laptop on a single battery (brick says 150W, I still haven't gotten a tester to check that) and have seen it sit at 13.2 for hours before dropping to 13.1, which it then sits at for a couple hours more.  By the time I get down to 12.8 I've usually laid down for a nap. lol

  As for the "can only put a single panel on a minivan' remark, I will have to go ahead and disagree with you on that one.  I am in a 1993 Mercury Villager and currently have three 100 watt panels on my roof.  There is literally no roof space left and they are the squarish SanTan ones, but they are up there and they even tilt (thanks, Doug!).  By the way, if you can set up your panels to tilt DO IT, tilting my panels practically doubles the throughput on them.  I have seen my charge controller go from 10.something amps charging to over 19amps just by tilting them (and that was winter in Quartzsite).  I'll take a pic sometime.

[rvpopeye]

I considered those LiTime ones + thinkin' it might be my time for LiTime ? Have you had it long , how zit workin' out ?
Likin' the looks of a Renogy smart LI too. (already Renogy for the rest so would integrate well.)

[sternwake]

I've no experience cycling Lifepo4, but in the process of making a 102P battery from 18650 cells for my electric skateboard.

I am going to bypass the BMS for discharging,, but I have to run a balance lead from BMS to each of the 10 parallel groups.

Once I need new house batteries for my Van, getting 4 280AH Lifepo4 prisimatic cells and a 200 amp JK or JBD smart BMS should be cakework compared to making this Skateboard battery, which has to deal with insane vibrations and deck flex and potential wild temperature swings within the enclosure, and possibly moisture intrusion too..

I intend to avoid the Lithium drop ins unless they start reliably using high quality new cells, and high amp BMS's, and are price competitive with a full DIY prisimatic lifepo4.

I was always intimidated by the BMS's, but realized I had basically become the human BMS with lead acid, and the skills transfer easily.

Popeye, you got the skills to assemble your own.

https://www.18650batterystore.com/collections/lifepo4-prismatic-cells/products/eve-lf280k?utm_campaign=16284236520&utm_source=g_c&utm_medium=cpc&utm_content=640203597579&utm_term=_&adgroupid=149985338811&gad_source=1&gclid=CjwKCAiA7t6sBhAiEiwAsaieYrBoYcRaPglv5292-ANcannPeWJUxAu6EWNDgxIrPjsiXcxaWDEU7xoCUoEQAvD_BwE

https://www.ebay.com/itm/165963813568?chn=ps&var=465463999540&_trkparms=ispr%3D1&amdata=enc%3A1Sd99WcTwQ8-iZebMzAlmMg75&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&mkscid=101&itemid=465463999540_165963813568&targetid=1585159292091&device=c&mktype=pla&googleloc=9012310&poi=&campaignid=19894961968&mkgroupid=148855406073&rlsatarget=pla-1585159292091&abcId=9307911&merchantid=113356128&gclid=CjwKCAiA7t6sBhAiEiwAsaieYg3rrciHrqmmsL2nB2KvepucJzjhkkNPyA_BHP9MZbMGn__l1kWSEBoC4OQQAvD_BwE

Will Prowses drop in tear downs reveal too much variation among the same brands.
I enjoy videos by this guy regarding cycling Lifepo4s and how BMS's function, and how to set up the Para meters.

[Cavinaar]

I considered those LiTime ones + thinkin' it might be my time for LiTime ?  Have you had it long , how zit workin' out ?
Likin' the looks of a Renogy smart LI too. (already Renogy for the rest so would integrate well.)

     I can't speak on Renogy batteries, never having used them.  However the LiTime batteries seem to be working well for me.  

  I tried to add videos of Will Prowse's tear downs of LiTime and Renogy batteries but the forum wouldn't let me.  They can easily be found on YouTube, though.

  Will Prowse, from what I have seen, also appears to recommend LiTime (though he doesn't agree with the name change) for a low-cost option. The one he tears down is one that has temp protection, which the really low-budget ones do not have.

  The Renogy year down video is admittedly a few years old but is likely still relevant unless Renogy has just stopped giving a crap (which I doubt).  Apparently, at least at that time, the Renogy battery he tore down was almost a much as a BattleBorn (he mentions that it was about $50 cheaper than a BattleBorn).  It is apparently an awesomely built battery, though, that uses pouch cells.

  A quick look on Amazon shows that the Renogy batteries are still slightly more expensive than the LiTime versions, but may be worth it if the build quality is so much better.  This isn't to say that the LiTime batteries are not well built just not as well built, apparently, as a Renogy ones.

  Since, from what I gathered from your post, the rest of your system is Renogy (and if you have the extra to pay for them) I would likely recommend going ahead and getting the Renogy ones. The various pieces of the system would likely talk to each other well.  But take that with a grain of salt as I still consider myself somewhat of a newbie on this topic.

[rvpopeye]

Yes young Will is not a stranger around here!
He has developed some skills as well as disposable cash to experiment through his Yooboob vids.
I've been doing solar since 2001 and still use that old Siemens 75 w panel I got for only $600 but it has friends now.
I was mainly interested in your non Will experiences with that LiTime. THX for your input !
Already mostly decided on the Renogy smart LIP4 . it's only 26# !

(I asked an oldtimer at the SKP Ranch back in the 90s? what was the best panel to buy ?
He just said , "The red ones"
Never having seen a red panel , so it took me a minute........Honda 2K ! ) LOL
I went Siemens and a SWPP MPPT ,later named Blue Sky. and a Link10 meter. Sold the 6.5K Onan to finance that batch.

Got a RED in'06 after a particularly good gig in Nashville though. And ya know....That guy was right. It always works ,,,,even in the dark ! skuh kuh kuh kuh
That Onan was hundreds of #s , the solar stuff less than 20#. Win ! Weight reduction is a GOOD thing for living on wheels.....the solar has gained a few # since then but this batt will replace just a "few" more # of LA (maybe 150#).
Another win . maybe a double too , LA is double+ up in price since before C19........