Lithium LTO batts/ HO alt

[Bobbytwonames 5,000+ posts]

You can find charts comparing voltage to state of charge (SOC): https://www.researchgate.net/figure...ured-at-different-temperatures_fig4_324117029

2.8V is '100%' SOC, with 5s that's 14V, with 6 that's 16.8V. That's why people told me if I want to run 5s, drop my voltage.


If you run 6S at 15.5 you get ~2.6V which is >95%.

It also makes sense why people here can run 6S on the standard voltage, 14.4/6 =2.4V per cell, or ~80% capacity.

The cells that I run can hold up to 2.9v each without a problem. So that is 14.5v which is perfect for my 14.4v system. It's up to you if you want to spend the extra money unnecessarily.

 

[Oinkypig 10+ year member]

Got 12pc 40ah yinlongs. actual capacity is 35ah. probably relabeled 30/35ah. Now LTO does accept charges of <2.9v BUT when a load is applied the voltages drops quickly to 2.1-2.3v. THE actual usable voltage of LTO is in fact 2.1-2.4 volts, definitely NOT 2.9volts. Allbeit, LTO batteries are great for accepting the higher 14+voltages. Less points for a 5s vs 6s. 5s is 2.4vx5 which is 12 volts. The very moment you started stressing the batteries, it is just detrimental to capacity in 5s config.. 6s should be steady at 14.4 volts, and anybody running in the 15+v range is using supercapacitors. The benefit of these posting on High voltage systems is contributed by the fact that they also use supercaps. They rebound very quickly to 15-16 volts. A partially charged 6s is the way to do it, if you want to use 14.4volts stock. Any external regulated 15+ volt alternator would need another upgrade to supercaps.

 

[hispls 5,000+ posts]

For what it's worth, the 5s Toshiba bank I put in my 4-wheeler is resting at 13.4V and I haven't driven that in a couple weeks. That said, we did 6s banks in my Jeep and my brother's Civic for audio and they perform admirably at <15V charging.

At some point I'm going to build up a larger bank of the Toshiba cells for testing.

 

[Oinkypig 10+ year member]

Each cell weighed 1180grams. Again either depleted electrolytes of a used 40ah or new 35ah yinlong. Heres all the testing I weighed in on both banks. Discharge of 17v and 15.2 volts and got 35ah of capacity either way. At least for these cells 2.3-2.4v is the optimal absorption for charging and discharging. While charging with the dc supply. The most time it took for absorption was between 13~14volts. After charging rises much quicker past that to 16+ volts. I got these 12 cells from aliexpress on sale for $393 all in all. Try grabbing the 12pc 40/35ah on sale again before spending 50% more for half the capacity. The sale will probably hit in a month or two.

 

[sjholland]

Hi, thanks for the discussion, I was trying to figure out exactly how I was gonna go about this.
Now I'm not sure if I should run 5s or 6s? I have six already but want to run with a agm for better or worse but hopefully okay.
My battery(agm) sits around 13 with the vehicle off, and while charging it looks like the average is about 14- 14.1. I just have a smaller amp on two tens and just want have as less voltage drop as possible. I have a supercap (ultracap) and is decent already but haven't replaced my alternator but considering, with one that supposed to put out double over stock amp wise. I realize the agm might pull on the yinlongs a little bit but wanted to try and balance them as good as possible and now wondering 5s or 6s for about 14 volts. Anyway I guess once I build the yinlong bank I could see what the voltage look like but just thought I'd ask, and thank you sincerely.
Nice little forum and glad I come across.

 

[mat3833 10+ year member]

Hi, thanks for the discussion, I was trying to figure out exactly how I was gonna go about this.
Now I'm not sure if I should run 5s or 6s? I have six already but want to run with a agm for better or worse but hopefully okay.
My battery(agm) sits around 13 with the vehicle off, and while charging it looks like the average is about 14- 14.1. I just have a smaller amp on two tens and just want have as less voltage drop as possible. I have a supercap (ultracap) and is decent already but haven't replaced my alternator but considering, with one that supposed to put out double over stock amp wise. I realize the agm might pull on the yinlongs a little bit but wanted to try and balance them as good as possible and now wondering 5s or 6s for about 14 volts. Anyway I guess once I build the yinlong bank I could see what the voltage look like but just thought I'd ask, and thank you sincerely.
Nice little forum and glad I come across.

You need an isolator for your LTO or you need to ditch the AGM. I would run 6s, it's what I built and my voltage is stable with 5000w+ of draw.

If you run the AGM in parallel with the LTO your AGM will pull the LTO down to 13v, my LTO rests at about 14v.

Matt

 

[sjholland]

2.9v X 5 cells = 14.5v. Most vehicles these days will only charge up to 14.5v unless an external regulator is used. I've seen my 5s bank get up to 14.7v. I'm pretty sure that my 5s bank could hold 15v without gassing out. My alternator won't charge it up that high so I'm not worried about it.

Do you know where the 5s bank rests at? Do you have a relay or isolater? I just thought I'd check because I was considering doing the same.
I have six already and haven't installed them yet. I have a agm that sits at 13 with stock alternator currently going to a ultracap and then the amp. I wanted to add the lto cells in parallel with the agm battery. If 5s rest at 13, I'd be good. Thanks, happy New Year to everyone.

 

[mat3833 10+ year member]

Do you know where the 5s bank rests at? Do you have a relay or isolater? I just thought I'd check because I was considering doing the same.
I have six already and haven't installed them yet. I have a agm that sits at 13 with stock alternator currently going to a ultracap and then the amp. I wanted to add the lto cells in parallel with the agm battery. If 5s rest at 13, I'd be good. Thanks, happy New Year to everyone.

You need 6s or you need to regulate your alt down to a minimum of 14v. I was on the fence about 5s/6s as well. If my sketchy ass decided 5s was potentially unsafe, you should probably listen, lol.

Your AGM and lithium will constantly fight each other with the car off. You do you, but I removed my AGM after testing the lithium. If I was going to keep the AGM, I would have isolated the Lithium at the power wire going into the bank. Only need a 200a isolater that way.

Matt

 

[winkychevelle 10+ year member]

Hi, thanks for the discussion, I was trying to figure out exactly how I was gonna go about this.
Now I'm not sure if I should run 5s or 6s? I have six already but want to run with a agm for better or worse but hopefully okay.
My battery(agm) sits around 13 with the vehicle off, and while charging it looks like the average is about 14- 14.1. I just have a smaller amp on two tens and just want have as less voltage drop as possible. I have a supercap (ultracap) and is decent already but haven't replaced my alternator but considering, with one that supposed to put out double over stock amp wise. I realize the agm might pull on the yinlongs a little bit but wanted to try and balance them as good as possible and now wondering 5s or 6s for about 14 volts. Anyway I guess once I build the yinlong bank I could see what the voltage look like but just thought I'd ask, and thank you sincerely.
Nice little forum and glad I come across.

Run 6s. 5s is sketchy and that 2.9v everyone keeps spewing is at best absolutely max charge which isn't good on the cells.

99% of lto out there is a max of 2.8v not 2.9v which is why everyone questions the 2.9v on scibs and whatever cells triggerman is using here which iirc is yinlong which are known to be max of 2.8v so idk where he is getting his numbers. I can't see his post anyway. But seeing as he is the only person I've every blocked in 13years you'll have to excuse the fact that I don't want his knowledge and much rather trust hispl and mat3833 along with my own knowledge.

I also say ditch the agm the lto will crank the care just fine without it

 

[sjholland]

Thanks everyone for the help, and happy New Year.

 

[Bobbytwonames 5,000+ posts]

Do you know where the 5s bank rests at? Do you have a relay or isolater? I just thought I'd check because I was considering doing the same.
I have six already and haven't installed them yet. I have a agm that sits at 13 with stock alternator currently going to a ultracap and then the amp. I wanted to add the lto cells in parallel with the agm battery. If 5s rest at 13, I'd be good. Thanks, happy New Year to everyone.

The 5s will always rest where your AGM rests at if you don't isolate the lithium.

 

[Bobbytwonames 5,000+ posts]

Do you know where the 5s bank rests at? Do you have a relay or isolater? I just thought I'd check because I was considering doing the same.
I have six already and haven't installed them yet. I have a agm that sits at 13 with stock alternator currently going to a ultracap and then the amp. I wanted to add the lto cells in parallel with the agm battery. If 5s rest at 13, I'd be good. Thanks, happy New Year to everyone.

The 5s will always rest where your AGM rests at if you don't isolate it.

 

[sjholland]

The 5s will always rest where your AGM rests at if you don't isolate it.

Thanks, I ended up giving this a shot. I had six of these cells, and 48 headway cells to choose from.
I went with the 5s & have a ultracap, and has seemed to do the trick and was exactly what I needed.

 

[Bobbytwonames 5,000+ posts]

Thanks, I ended up giving this a shot. I had six of these cells, and 48 headway cells to choose from.
I went with the 5s & have a ultracap, and has seemed to do the trick and was exactly what I needed.

Thanks for that!

 

[Bobbytwonames 5,000+ posts]

Look boys. The 5(s) worked.