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bmwking last won the day on January 27

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About bmwking

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  • Birthday 06/10/1982

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    Ferndale, MI

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  1. yes it does actually, but the duration of time is important here. that 3C continuous (or ~180A) is for ~15 min max before the battery is drained below it's usable charge. short duration discharges are the line right below where you read that, noted at 10C (~600A) for 5 seconds per minute. which makes it an excellent choice for the demands of music
  2. yes and no, you can get a lower aH rating and make use of a lithium battery's inherent higher C rating. Hence the ability of Limitless to sell 15ah lithium packs. Personally, I wouldn't ever use such a small one, but that's just me. I'm sure it has it's applications. Ideally you want a lithium with at least a 7C rating, in my experience at least. to make sure you can handle the current needs of your system. couple that with at least a 60aH rating and you have a recipe for a battery that can handle at least 400A max discharge bursts.
  3. for sure, i get what you're saying. however, i ain't never seen a 1gb drive the size of a tablet lol. if we're talking internal HDD, the 3.5" standard has been around for at least 35 years now. back when platter drives were a thing they were bigger than records and held much less. a better comparison would be a 1tb microsd vs a standard 3.5 1tb drive (which did you know the 1st 1tb 3.5" drive came out in 2007?) all that's semantics tho, i still get your point. im just a tech nerd so i like that stuff as far as capacity, that's the amp hour (aH) rating. higher number, longer life. all things being the same, sure you could get like 100 18650 AA batteries and figure out how to series parallel them all to get a final load of 12-13v at rest so you could have the equivalent of a ~60aH battery, and then get a sophisticated BMS to keep each cell topped up. or... you could get 4 of the cells i linked and achieve the same if not a better result. so it's down to simplicity. oh and safety. CALB cells are known for their inherent safety when it comes to automotive use. the 18650s are... much less so.
  4. bmwking

    Cap or not

    sounds like you answered yourself
  5. bmwking

    Cap or not

    no. use a battery. unless you're doign a bank of maxwell caps, a capacitor is trash. your alternator and 1 agm battery is more than capable of handling 1000w
  6. think of it like this, if you were having a party with a lot thirsty people coming, would you want a keg or a single 12oz bottle to share? the cells i linked are like a keg, the 18650s are like a single bottle. same beer(voltage), but one has a lot more to give.
  7. 1. That's my understanding (if I'm wrong hopefully someone else chimes in). Max amps means the max amperage the cells can output for a specific amount of time, youll see a max discharge rate noted as a number+C then usually a time duration for said max rating. 2. yes, each cell is rated for 70aH. these are an updated version of the cells im using, with a lower aH rating 60 vs 70 which i have, max discharge current of each cell is 600 amps, this number does not combine with more cells, it will be the total across the bank regardless of the final voltage load they get wired to: you could get 4 of these and connect them to present a 12.8v final load with a max charging current of 16v, so well within a vehicles charging voltages. 3. the difference is basically reserves. physically a smaller battery cannot hold as much reserve as a larger battery. a smaller battery will discharge much faster than a large one. 4. the amp rating youre seeing is the dumbed down max discharge rate. however, if it does not give you a C rating and time duration, I'd assume this is a 1 second max rating, which will not do well in audio. you are correct in thinking that a 12.8v bank of the 200 amp cells would not do much good when presented with an amp that's attempting to pull double it's rated discharge current. my pleasure, we're all here for the same reason, to get smarter and bang harder.
  8. yes that is the C rating the 18650 cells are small batteries, like AA size, and in no way adequate for our application. the 38120s have more material inside (hence larger) and can handle more current for more time. this is why people can use 38120s in large banks to provide a voltage stiffener, but not replace an actual full size battery. my total bank is a 4 x 3.2v cells (12.8v total) each cell has a 70aH rating and a 10C rating. it's my (albeit basic) understanding that the C rate is the number preceding the C (ie 10C) multiplied by the aH, giving my a max discharge current of 10C or 700 amps, for short 10 second (max, before the C rate lowers) bursts when needed.
  9. I would message the owner or whoever you talked to and ask him what the C rate of the battery you're interested in is. This will tell you whether or not its going to be a good battery for our hobby. You want a high C rate. I sourced a custom 70aH LiPo bank with a 10C Max discharge rate (10s), meaning it can supply 700 amps for 10 seconds at full discharge. Now, my equipment isn't pulling 700 amps even at max discharge (full volume, on tuning, bass notes) so it allows me to show near full voltage during music, and when it does pull down a little, my 270a alternator is right there to supply it with what it lost, giving me a near instant snap back to 14.4v-14.6v.
  10. @WalledSonic looks like this guy could use some of your genius.
  11. a lot of people do a box port in the center over the driveline hump. not sure which will get louder, passenger side port or center front. check out
  12. so... they made an alternator 7+ years ago with a copper stud, and you're butthurt because you didnt do the research before giving someone $400? get boned man. it sucks to feel like you were led on, but when you led yourself on because you couldnt be bothered to read... well... lets just say mechman isnt the idiot here. take your whining back to facebook.
  13. Could definitely have back fed the factory amp. Chrysler likes to include a cheap weak amp. Do a Google of your car and see if there's anything about a factory amp.
  14. is the plug that youve been plugging everything into properly grounded? like if you take the plate off the wall and pull the socket out of it's box, does it have a black, white, and green wire going to it? (assuming you're in the usa). that's the only thing i can think of that's common in the hum, the outlet you've been using.
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