slowfkncar

Yup either junkyard or you'll have to search mouser electronics for the harness & pins to build your own.

^^^ 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.

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.

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.

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..

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.

What do you mean thread + to +? You can stack what you want with m6 studs or connect them onto a buss bar. Regardless of what you do, you'll always need 4 sets of parallel cells wired in series, so 24 cells/4= 6 cells in parallel.

Balancing (BMS) is strictly for cells in series but it might also provide temp-cut off and discharge/charge limited circuits. If you drive 14.6v into a pack of 3.65v cells, they need to stay at the same voltage 100% of the time or you'll end up with an overcharged/undercharged cell or more, you overcharge once and that cell will never perform the same again.

16 cells of the above in 4s4p would give you 40ah/12.8v (14.6 max) assuming the capacity isn't inflated. I have not had a negative personal experience with lithium yet & I've lost count of how many LFE packs and solar power walls i have built/worked on. For car audio my experience is float voltage is higher and voltage doesn't swing as much, i can demo all the way to 10% without the engine running an my car still starts, obviously if your are trying to pull more then the pack can handle then your going to have bad results.

Yeah bro you can shape them into any size you want, as long as you keep it wired in 4s and have enough in parallel to take your charge/discharge current. Im also using headway 38120 (4s24p) in one of my cars and love them, i have three rows of 32 cells that lay flat below my amps, this opened up a shit load of room after removing 2 aged d3100's. I've been wanting to try the prismatic LFP's at batteryspace but im not sure of the quality at that price, the specs are nice for car audio.

I thought you already tried a new power supply outside of the car? If you take this amp and power it on your test bench, jump the remote to 12v and just plug in your speakers, still got hissing?

That amp sounds damaged/defective.

I don't buy shit from them after my last experience, looks like an sa18 to me also.

It is equipped with an electronic load detector, which uses a shunt inside the underhood fuse box. I actually forgot how to bypass it for that year, pretty sure it was an inline resistor to keep ecu eld reference voltage low.

Where are you reading voltage from? Where did you tap the line at? Use a DMM, compare your voltage between the front alt lug and rear battery while at idle, if they are within 2% then lets stop checking wires. Sometimes when batteries age or stored at low voltage or even when you add more, it can put more of a load on the system, because of this i would attempt to disconnect the rear battery and see if your voltage jumps back up to where you had it, if not you either still have a load you don't know about or a bad diode or two within the alt. Have you tried fully charging those batteries on an external charger? 12.1 is pretty low and would for sure put a bigger load than a fully charged d3100.