Litium car audio batteries

[Chris McNeeley]

Why step away from iron phosphate?

titanate has more than 2x the cycle life, recharges even faster, and biggest one for me is -40 degree temp rating. Kevin at mi solar is making me a custom 16v 115ah as we speak.

 

[kr15 5,000+ posts]

Im not a chemist to know WHY, or what specifically is going on. But most ppl I know who jumped on the hype train and converted large agm and or cap banks to lithium, lost on the meter. Lithium is weird, it will deliver its amperage burst, but will still drop. Anyone that chases tenths will know that 5k clean at 14v will meter louder than 5k at 11.5v.

I tested a limitless 15ah, supposedly good for 3k on stock alt, vs a group 31 deka agm. The deka was stronger, clamped more power, and metered higher. That 15ah stopped making clean, usable power for me around the 2k mark.

A teamate of mine went from 80ah JY plus 6 banks of caps, to 160ah of lith only. He lost 1 full db on the meter.

Adam Dukes told me at finals that when he went from a huge agm to lithium bank, he lost. He is now converting to a massive cap bank.

As a burp guy, id personally prefer 1 bank of caps per every 1-2k clamped. The downside of agm is space. I like about 50ah per 1k, for virtually no drop. So clamping 5k for example, thats 2-3 g31's already.

Caps and agm would be my preferred combo for a smaller setup. Caps and lith for larger. The caps should be wired in after the battery.

I dont know the chemistry reasons. I just know what loses and what doesnt, and i know what the loud people at finals were doing

 

[Hertz Mafia]

Alt power and AGM for daily use //content.invisioncic.com/y282845/emoticons/suave.gif.858fc102f7646e678ee8af7e1fbc41d1.gif

 

[shizzzon 10+ year member]

Chris, go do some research on what the C rate is based on temp of LRO cells.

Sure it says to -40 whereas most lifepo4 is to -4 - 20..

But look at the C rate.. for car Audio, it's unusable c rate.

Now, these cells are encased in a sealed enclosure, therefore they don't stay cold so the temp difference is minute.

Cycle life, not tested at high c rate yet...

So for car Audio use, it's unknown.

Sure it may be better than others but everyone is using small ah lithium which means that higher cycle life isn't much different than large ah agm.

Only good benefit of lto for sure is 0% carbon.

Using 5s LTO, any large load tanks below 12v.

There are currently no LTO cells that rival the best lifepo4 in terms of discharge performance.

Recharge they do but not discharge.

Lto will evolve.. just not there yet.

Kr15, let me get on a computer to respond to you, lol.

 

[Chris McNeeley]

Chris, go do some research on what the C rate is based on temp of LRO cells.
Sure it says to -40 whereas most lifepo4 is to -4 - 20..

But look at the C rate.. for car Audio, it's unusable c rate.

Now, these cells are encased in a sealed enclosure, therefore they don't stay cold so the temp difference is minute.

Cycle life, not tested at high c rate yet...

So for car Audio use, it's unknown.

Sure it may be better than others but everyone is using small ah lithium which means that higher cycle life isn't much different than large ah agm.

Only good benefit of lto for sure is 0% carbon.

Using 5s LTO, any large load tanks below 12v.

There are currently no LTO cells that rival the best lifepo4 in terms of discharge performance.

Recharge they do but not discharge.

Lto will evolve.. just not there yet.

Kr15, let me get on a computer to respond to you, lol.

Well it cost me 2,500 so I guess ill be the guinea pig.

 

[wew lad 5,000+ posts]

Chris, go do some research on what the C rate is based on temp of LRO cells.
Sure it says to -40 whereas most lifepo4 is to -4 - 20..

But look at the C rate.. for car Audio, it's unusable c rate.

Now, these cells are encased in a sealed enclosure, therefore they don't stay cold so the temp difference is minute.

Cycle life, not tested at high c rate yet...

So for car Audio use, it's unknown.

Sure it may be better than others but everyone is using small ah lithium which means that higher cycle life isn't much different than large ah agm.

Only good benefit of lto for sure is 0% carbon.

Using 5s LTO, any large load tanks below 12v.

There are currently no LTO cells that rival the best lifepo4 in terms of discharge performance.

Recharge they do but not discharge.

Lto will evolve.. just not there yet.

Kr15, let me get on a computer to respond to you, lol.

you've brought up, in my opinion, the biggest factor with lithium batteries as it's been for the last 15 years. It's a huge factor in RC, then it was a big factor in 18650 for vapes, and now we're finally seeing some concern for it in car audio.

this is a reason why people will complain about the voltage drop of cells as well without realizing the voltage stays very stable once a load is applied until the battery is ~80-90% depleted. Then it falls off a cliff and is (in my opinion) useless for car audio as it will give you almost nothing in output with massive loss in voltage

it's a balance with chemistry between C rating, stability, and cycle life

until we get to the point that cells are cheap enough to be used without worry for cycle life because we only use a low depth of discharge, lithium will be an overly expensive product that doesn't even perform at its peak

 

[hispls 5,000+ posts]

Yea. And you can buy cells and build a 48ah for 500.. good for about 6k.

Where can one buy these cells?

 

[Papermaker85 5,000+ posts]

Where can one buy these cells?

I did a good search..

 

[kr15 5,000+ posts]

Where can one buy these cells?

Headway 8ah cells

Or Tenergys.

Weve tried both. Both "work", neither are without minor flaws

 

[shizzzon 10+ year member]

Those aren't good enough.

The cells we have here, at 46ah will produce up to 730A holding 11.9-12.0v with no charging support for close to 3 minutes straight before rolling off.

Cost? $640 shipped to your door.

These are raw cells so no case. Must build your own casing for thermal control if you have cold winters.

That combination will also burst 1100A+ to 11.7v. That's 25C... and that's no where near their limit. (although we suggest building lithium packs to focus on maintaining above 12v for safety and for higher performance for amplifiers.) The Mean shut down point is 6.4v, Mean pack shut down- 8.0v, suggested shut down- 10.8v

Kr15, i'll have to respond later. Stuck into doing some more research again with Spllab for the rest of the day.

 

[kr15 5,000+ posts]

Each cell is 46ah? These are 3.65v or something else?

If so, 4 in series would make a 46ah battery.

 

[shizzzon 10+ year member]

They are 4.3 but when we were testing over 8C, we re-rate them as 4.2ah. They never fell below 4,240mah when recharging them from a discharge durational test up to 16C.

 

[Papermaker85 5,000+ posts]

Those aren't good enough.
The cells we have here, at 46ah will produce up to 730A holding 11.9-12.0v with no charging support for close to 3 minutes straight before rolling off.

Cost? $640 shipped to your door.

These are raw cells so no case. Must build your own casing for thermal control if you have cold winters.

That combination will also burst 1100A+ to 11.7v. That's 25C... and that's no where near their limit. (although we suggest building lithium packs to focus on maintaining above 12v for safety and for higher performance for amplifiers.) The Mean shut down point is 6.4v, Mean pack shut down- 8.0v, suggested shut down- 10.8v

Kr15, i'll have to respond later. Stuck into doing some more research again with Spllab for the rest of the day.

Thing is I don't need 110 amp at 11.7. I need it at 14.8. Lol

 

[shizzzon 10+ year member]

that example above would use 44 cells, 4s11p, 3.6v max suggested charging, 3.65v, no benefit, 3.8v absolute max.

 

[shizzzon 10+ year member]

Thing is I don't need 110 amp at 11.7. I need it at 14.8. Lol

you would need higher voltage charging.

If you did lifepo4, you'd be resting at 16.5v with parasitic load or 17.5v if you keep them isolated.

Charging for them would be 18.0v max, 16.9v minimum to 90%.

Usable capacity- once it hits 14.25v, not much left in pack (assuming gradual roll off, not burst of power)

If LTO, there are some slight variations but generally it would be-

6s (not 5s), Charge- 16.8v max, resting- up to 16.8v if kept isolated, up to 16.4v if parasitic draw

Usable capacity- once it hits 13.2v, not much left in the pack. (assuming gradual roll off, not burst of power)

Lifepo4 would give you much more consistent power because it's power band is in the upper voltage range only but requires higher charging.