Who’s built their own lithium bank?

[slowfkncar]

19 minutes ago, JakeW said:

I mean stacking them 2 tall. I realize you can always do separate banks with buss bars. But picture from top to bottom, buss bar, then 2 cells connected by all thread then buss bar. Creating a “taller cell”

Yeah you can stack them directly with m6 studs but if your cells arent fixed into position you might need to use lock washers or lock nuts so that the bass don't vibrate the cells loose of the stud, you'll need a bar for the top.

 

[JakeW]

Just found these, with holder and buss bar included. Just hard to decide 4,8,12,16,20,24.... like where do you stop? Lol is there anything limiting adding to it later? And I see people must charge their lithium if it sits. But if these came, could I just build it and toss it on?? Minimum minimum.... how many cells to overcome 80ah AGM?

[JakeW]

Or four of these? Damn

[slowfkncar]

1 hour ago, JakeW said:

Just found these, with holder and buss bar included. Just hard to decide 4,8,12,16,20,24.... like where do you stop? Lol is there anything limiting adding to it later? And I see people must charge their lithium if it sits. But if these came, could I just build it and toss it on?? Minimum minimum.... how many cells to overcome 80ah AGM?

You stop when it makes you sleep better lol & yeah its normal for voltage to drop with time but it would take a pretty long time to sap all the current from a decent size pack, much longer than a comparable lead acid.

 

If your cells are capable of straight up taking the current from your alt, and you have a bms then yeah just throw the pack on, start it up and charge. Your cells should be shipped at the same voltage, if its not then parallel ALL the cells for 24 hours before assembly.

 

It can get a little tricky when calculating lead acid capacity over lithium, after factoring a 50% DOD and the peukart effect, id say subtract 40% of your lead acid capacity, 30% would be better for less voltage drop etc..

[slowfkncar]

I should have mentioned above, if you oversize the pack a bit, you'll get more life cycles out of it.

 

LFE at 1C has an average cycle life of 2000+, limiting your discharge to 0.5C can give 2 to 3 times more cycle life.

[JakeW]

9 hours ago, slowfkncar said:

You stop when it makes you sleep better lol & yeah its normal for voltage to drop with time but it would take a pretty long time to sap all the current from a decent size pack, much longer than a comparable lead acid.

 

If your cells are capable of straight up taking the current from your alt, and you have a bms then yeah just throw the pack on, start it up and charge. Your cells should be shipped at the same voltage, if its not then parallel ALL the cells for 24 hours before assembly.

 

It can get a little tricky when calculating lead acid capacity over lithium, after factoring a 50% DOD and the peukart effect, id say subtract 40% of your lead acid capacity, 30% would be better for less voltage drop etc..

Sorry for being such a noob man!! I think a pack of 24 would be sickkk

[slowfkncar]

6 hours ago, JakeW said:

Sorry for being such a noob man!! I think a pack of 24 would be sickkk

We all start somewhere bro, a pack of 24 would be nice.

 

 if you are planning to completely remove your agm, then i would at least make sure that i purchase legit cells.

 

 A legit 38120/p can discharge at 100A - 160A continuous, and usually have a 50-60a max charge rate, look up the charge/discharge specs before buying anything.

[Dafaseles]

14 minutes ago, slowfkncar said:

We all start somewhere bro, a pack of 24 would be nice.

 

 if you are planning to completely remove your agm, then i would at least make sure that i purchase legit cells.

 

 A legit 38120/p can discharge at 100A - 160A continuous, and usually have a 50-60a max charge rate, look up the charge/discharge specs before buying anything.

Are there any brands you would recommend? 

[JakeW]

2 hours ago, Dafaseles said:

Are there any brands you would recommend? 

Yes please! I see red HP & regular 38120...

[slowfkncar]

^^^

Headway & a123 are the only two LFE brand's that I've tried, small individual cells let me make custom sized packs, I've seen people use alibaba LFE prismatics with horrible results.

 

The lithium market is cluttered right now, so many knock off/used/inflated cells going around so just take note of that.

 

A real 38120hp is supposed to be 8ah & 40a/160a (cont) charge/discharge , 38120s is 10ah & 30a (cont) charge/discharge, if what your looking at has different specs then it is either inflated,used or fake.

 

You don't necessarily need to stay with a 38x120 format cell either, 40x152 would be an even bigger cell with more capacity and they still have m6 terminals, you can get creative with your battery builds due to so many options.

 

Headway usa should have new cells, batteryspace has headway cells but i have no clue if they are authentic, they are a decent company though so an email/phone call should get you an answer, Solargeni might have some used ones and ebay/amazon means you'll be taking the word of seller and reviews.

 

Any day of the week id take the 38120hp over the S, you'll have 20% less capacity but 400% more discharge current.