LTO bank vs LiFeP04 for daily system

[Firewalker]

Nope '03 Explorer with the 4.0 flex in it with the stupid 4G alternator. I saw 15.1 a couple times after installing it but nothing since that 1st day.

 

[winkychevelle 10+ year member]

Nope '03 Explorer with the 4.0 flex in it with the stupid 4G alternator. I saw 15.1 a couple times after installing it but nothing since that 1st day.

If voltage stays below 14.8v I'd just stick with lifepo4 unless you want to run your amps at higher voltages.

Lto is stronger batteries at higher voltage so you get more power from the higher voltage alone. Plus a stiffer electrical system.

But amps with a regulated power supply won't care about or might even fault at higher voltage. Most amps can handle 15.5v and down but not all of them.

 

[hispls 5,000+ posts]

30AH of headway(prebuilt) with an alt.

But now you have a big honking alternator trying to charge cells that will ONLY give you rated cycle life if you charge them at 15A and will fail quickly if you attempt to charge them over 150A. I'd worry you hurt that on the charging side.

There's some pre-built bus bars for the 40AH yinglong cells by a few of the machine shops that make other audio power distribution type machined blocks. Not sure who has them in stock or the price but there's a few options I've seen, some pretty simple some really pretty.

6s lto
14.4v float 15.6 rec charge 16.8v max

That is NOT the specs I got for max charging voltage on my YingLong cells. Who is publishing those figures?

 

[mat3833 10+ year member]

But now you have a big honking alternator trying to charge cells that will ONLY give you rated cycle life if you charge them at 15A and will fail quickly if you attempt to charge them over 150A. I'd worry you hurt that on the charging side.

There's some pre-built bus bars for the 40AH yinglong cells by a few of the machine shops that make other audio power distribution type machined blocks. Not sure who has them in stock or the price but there's a few options I've seen, some pretty simple some really pretty.

That is NOT the specs I got for max charging voltage on my YingLong cells. Who is publishing those figures?

What are the specs you have? I'm getting differing information from multiple people and multiple places about 5/6s LTO vs 4s LiFeP04. If I'm stuck charging below 14.5 due to my ECU that would mean 6s LTO is basically off the board. If I want to maintain 13v minimum that should leave 5s LTO is good as is 4s LiFeP04.

I've seen 2.8 and 2.9v per cell as the max for LTO. If it's 2.9v that means 14.4-14.5v on 5s LTO is happy and I'm golden. Yes, the charge current would potentially be an issue if I ran 40ah. But I'm trying to compare apples to apples as much as I can before I get into the really fun part.

Man, this **** kills me. Someone needs to do some kind of series on this **** so us plebs can make a better educated decision.

Matt

 

[winkychevelle 10+ year member]

But now you have a big honking alternator trying to charge cells that will ONLY give you rated cycle life if you charge them at 15A and will fail quickly if you attempt to charge them over 150A. I'd worry you hurt that on the charging side.

There's some pre-built bus bars for the 40AH yinglong cells by a few of the machine shops that make other audio power distribution type machined blocks. Not sure who has them in stock or the price but there's a few options I've seen, some pretty simple some really pretty.

That is NOT the specs I got for max charging voltage on my YingLong cells. Who is publishing those figures?

https://files.gwl.eu/inc/_doc/attach/StoItem/6991/LTO-40AH-CY_datasheet.pdf

https://daylightsavingaustralia.com.au/wp-content/uploads/2021/04/Specification-of-LTO-2.3V-40Ah-66160-Cells.pdf

First 2 data sheets that pop up on google


So please post your source because everywhere I find is 2.8v max per cell Mac charge voltage. 2.8v×6cells in series=16.8v

Even at 2.9v you get 14.5v at 5s but you are charging at the absolute max voltage. And I'm finding many more sources for 2.8v per cell and none for 2.9v If you want to run your cells at the ragged edge and risk lifespan or failure go ahead I'm not going to.

Depending on the specific lto cell they have a nominal voltage of 2.3v or 2.4
2.3x6=13.8 2.4×6=14.4v

 

[winkychevelle 10+ year member]

What are the specs you have? I'm getting differing information from multiple people and multiple places about 5/6s LTO vs 4s LiFeP04. If I'm stuck charging below 14.5 due to my ECU that would mean 6s LTO is basically off the board. If I want to maintain 13v minimum that should leave 5s LTO is good as is 4s LiFeP04.

I've seen 2.8 and 2.9v per cell as the max for LTO. If it's 2.9v that means 14.4-14.5v on 5s LTO is happy and I'm golden. Yes, the charge current would potentially be an issue if I ran 40ah. But I'm trying to compare apples to apples as much as I can before I get into the really fun part.

Man, this **** kills me. Someone needs to do some kind of series on this **** so us plebs can make a better educated decision.

Matt

https://youtube.com/c/mazda2284

 

[hispls 5,000+ posts]

What are the specs you have?

The dadasheet from my guy in China said 2.6V and the Russians who were using these cells before anybody in the USA said they charged their 6S banks no higher than 15.5V.

The real issue is that most of these car audio battery "brands" are trying to sell you something and it seems like all of them are withholding information either to mislead you on the capabilities of what their product can do or out of fear that if people figure out what cells they use by extrapolating those stats they'll just buy the raw cells for 1/3 of the price and DIY.

 

[winkychevelle 10+ year member]

USED HEADWAY 38120 HP 3.2V 8AH LIFEPO4 BATTERY

THESE CELLS HAVE NOT BEEN CAPACITY TETSTED BUT THEY ARE GUARANTEED TO ARRIVE WITH GOOD VOLTAGE AND ALL WERE REMOVED IN WORKING CONDITION FROM BACKUP STARTER BATTERY PACKS. WE GUARANTEE NO DEAD CELLS AND AT THIS PRICE YOU CAN'T GO WRONG. NO COMPRESSION NEEDED FOR CYLINDRICAL CELLS. THESE ARE BIG...

batteryhookup.com

The dadasheet from my guy in China said 2.5V and the Russians who were using these cells before anybody in the USA said they charged their 6S banks no higher than 15.5v.

The real issue is that most of these car audio battery "brands" are trying to sell you something and it seems like all of them are withholding information either to mislead you on the capabilities of what their product can do or out of fear that if people figure out what cells they use by extrapolating those stats they'll just buy the raw cells for 1/3 of the price and DIY.

Yes you don't need to charge any higher than 15.5-15.6v to fully charge a 6s bank. 2.8v is the maximum before cell damage.

And you are right the car audio companies are withholding info and taking advantage of ignorant buyers.

Headway 38120 cells are 10c charge and 15c discharge though It depends on which cells you get exactly the blue 38120s is the slow cell the red 38120hp I'd faster thus better suited for car audio. This makes headways great for factory systems.

These are also 10c charge and 20c discharge. A better alternative to headways but less options from current bus bar makers

4PACK LISHEN 8.5AH 30C 3.2V LifePo4 Prismatic Lithium Cells

4PACK LISHEN 8.5AH Battery has grown its annual production capacity up to 10GWh and has maintained the major market. Lishen prismatic lithium cell.

srikobatteries.com

 

[hispls 5,000+ posts]

Headway 38120 cells are 10c charge and 15c discharge

Headway 38120HP 8Ah LiFePO4 cell

Extremely High C rate discharge version of Headway LiFePO4 cell(please check features below). Max Continue discharge10C(80A) and max discharge 20C(160A). Convenient to assemble battery pack with screw terminal diesign.

www.evcomponents.com

This says .5C and 5C max. Looks like the red 38120s that everybody uses.

The Lishen have a higher C rating but I'm not sure that outside of SPL burp applications you really want to give up storage for burst current. Dollar for AH you're definitely paying more for the high C cells. I've got some Toshiba high current cells here that I need to build up and test at some point but the fella who was going to help me has disappeared with 400$ worth of copper and really I don't know if I have time to get into a project even if I can get it back.

 

[winkychevelle 10+ year member]

https://cdn.shopify.com/s/files/1/0697/3395/files/data_sheet.pdf?v=1624630765

Max continuous charge 80amp 10c max continuous discharge 120amp 15c
I don't look at the burst discharge as staying in that range for too long can cook and damage the cell

 

[hispls 5,000+ posts]

https://cdn.shopify.com/s/files/1/0697/3395/files/data_sheet.pdf?v=1624630765

Max continuous charge 80amp 10c max continuous discharge 120amp 15c
I don't look at the burst discharge as staying in that range for too long can cook and damage the cell

Somewhat worrying that even retailers can't seem to come up with the same answer on specs on these things, but at least with Headways people have been using them long enough for DIY stuff that real world results can be found with enough digging through old solar forums or whatever.

 

[mat3833 10+ year member]

Wow, this is a clusterfuck...

OK, anyone using either cell type simple questions:

What is your charging voltage?
What AH do you have and what alternator do you have?
Are you running solo lithium or agm/lithium combo?
How much power are you actually running, not "amps rated for" power.

Matt

 

[HondaCRV03]

Wow, this is a clusterfuck...

OK, anyone using either cell type simple questions:

What is your charging voltage?
What AH do you have and what alternator do you have?
Are you running solo lithium or agm/lithium combo?
How much power are you actually running, not "amps rated for" power.

Matt

I charge at 14.4 cold drops to 14.2 hot
I have a 32ah headway bank linked to an 80ah underground power battery
320a alternator from Singer Alternator
Battery delete up front
I'm running about 5k total right now

 

[hispls 5,000+ posts]

Wow, this is a clusterfuck...

OK, anyone using either cell type simple questions:

What is your charging voltage?
What AH do you have and what alternator do you have?
Are you running solo lithium or agm/lithium combo?
How much power are you actually running, not "amps rated for" power.

Matt

We have 6s 240AH YingLong banks here, both charge 14.4ish. No AGM, Excessive Amperage 6 phase in the Jeep, stock alt in my brother's civic. Civic runs a very Korean amp but only clamps 3200 or so, I run two SFB 8Ks and have never clamped them.

 

[mat3833 10+ year member]

I charge at 14.4 cold drops to 14.2 hot
I have a 32ah headway bank linked to an 80ah underground power battery
320a alternator from Singer Alternator
Battery delete up front
I'm running about 5k total right now

Hmm, so you are using the 80ah as the "main" and the headway as the supplemental?

We have 6s 240AH YingLong banks here, both charge 14.4ish. No AGM, Excessive Amperage 6 phase in the Jeep, stock alt in my brother's civic. Civic runs a very Korean amp but only clamps 3200 or so, I run two SFB 8Ks and have never clamped them.

So you are just leaving a little on the table then only charging at 14.4. I'm guessing your vtage stays right at 14.2 or so under heavy load?

Matt