32 headway hp 8 ah lifepo4 or 12 18ah lto?

[Vogey84]

trying to decide witch way to go. 1. 32 slightly used headway hp 8ah lifepo4 cells already bus bared up in a metal case OR 2. 12 brand new 18ah 50c lto cells stating 30k cycles for $60 less. vehicle is a navigator with stock alt (300a here monday) stock batt under hood and 2 of the biggest deep cycle batteries walmart sells mounted outside the frame rails behind rear tires pushing a dbcomp 5 on 4 15s and arc audio 4150 . have a taramps hd4k goin in and a pair of alpine mpr 500s for mid bass ready to go in soon as well figure about 10k or so possible draw. what do you guys think? (there will be more added later as well) and if it makes a diff im in mn n reg see -20 or colder in the winter

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[Popwarhomie 5,000+ posts]

Well if you are going to be running AGM batteries as well you will want to go with headway cells. Unless you can get rid of your AGMs and run straight Lishen LTO cells. But you would want a larger bank as well. Probably would want 3-4 banks of Lishen.

 

[Vogey84]

3-4 more banks of 12 or 6 lishen? unfortunately it would be a few weeks b4 i can order more n probly take a month or 2 from china too, could i get away with mixing the lead acid and lto short term? or isolate them with a solenoid? or wait to install the hd4k till i get more? with the 50c lto would i see any improvement with a super cap bank? and can you get away with mixing lto / lifepo4?

 

[Popwarhomie 5,000+ posts]

3-4 banks total. 18-24 cells. A single bank can support around 3k. 20c discharge and 15c charge is more realistic. They are good down to -40F temperature.

No do not mix them with lead acid or agm.

If you are going to run a Taramps HD just know they high voltage protect at 15.3-15.4 volts.

 

[Vogey84]

thanks for the info, i 4ont dun that high 0f voltge

 

[hispls 5,000+ posts]

Let's just say the Lishen cells will reliably deliver at 50C, that's 900A, if we have 18AH capacity you will have a little over 1 minute reserve. My guy in China says these high C rating Lishen cells are the popular ones now for car audio applications, but I have not seen the discharge graphs for these. I would expect they start dropping voltage and current potential noticeably below 40% charge so real world I don't know what you would really expect by way of how long you could actually beat on things with so little reserve.

I would avoid the headway in general. If you must use old fashioned LiFePO4 see if you can't find some c-max cells instead. Those have a more proven track record for our applications.

I will say that LTO has far better performance in extreme cold. Published ratings are good and real world performance up here in Maine has been good.

I would suggest against mix matching batteries. If you can't afford to do the electrical system right you shouldn't be considering the type of build that will demand 800-1000A current. Keep in mind, perfect world, the difference between 5000W and 10,000 is only 3dB which is only 2 clicks on the volume knob and your expense all around will dramatically increase for a maybe gain.

As to how long LTO really lasts in our applciations it is far too early to say. There were some in use in Russia perhaps 4 years ago, my brother and I built our banks about 3 years ago now and AFAIK we were the fist ones in the USA using these for car audio so there just isn't any real world data for us yet to confirm or deny the 10-20-30 year claims. That said, LTO isn't exactly new and those cycle life numbers are likely pulled at least partially from EVs and backup power supply banks so they're probably at least close to accurate.

 

[Bobbytwonames 5,000+ posts]

Have you looked at Ying Long (spell check)?

 

[Vogey84]

Ain't them cmax cells 4.2v? Putting the charge just as high as lto and i thought they were lmo not lifepo4?

 

[hispls 5,000+ posts]

Ain't them cmax cells 4.2v? Putting the charge just as high as lto and i thought they were lmo not lifepo4?

I don't know much about them but I know they are more commonly used in car audio applications. I see a few banks at local shows in 160+ builds and they seem to get the job done.