Anybody try using 12v rechargeable lithium-ion batteries to power their class D amps? I have a 2024 based amp and wonder how long I would get on a charge?
An externally hosted image should be here but it was not working when we last tested it.
A 2024 (or 2021 and 2020) based amp uses about 350 mA at maximum volume. With that in mind it's pretty easy to calculate battery time.
Btw, there's is a new type lithium ion batteries that are far more practical, LiFePO4 or just LFP cells. These are the safest battery type in existence today. They're not just safer in every aspect than standard lithium ion, they are safer than any other battery type, rechargeable or not.
And with minimum 2000 cycles it's actually also cheaper than any other type of battery. It even has enormous charge and discharge rates, so pretty much perfect.
Btw, there's is a new type lithium ion batteries that are far more practical, LiFePO4 or just LFP cells. These are the safest battery type in existence today. They're not just safer in every aspect than standard lithium ion, they are safer than any other battery type, rechargeable or not.
And with minimum 2000 cycles it's actually also cheaper than any other type of battery. It even has enormous charge and discharge rates, so pretty much perfect.
Capacity/consumption.
So take the Ah rating (that means Amp hours) on the battery and divide with consumption (here 350mA) and you get how many hours you can expect it to run at maximum volume.
I can second the LiFePO4 cells idea. I just swapped out my old 4AH sealed lead-acid battery for this:
http://www.batteryspace.com/lifepo4beltbagpowerbattery128v68ah8704wh14aratefastsmartcharger.aspx
I have been a little cautious about too much draining, as the first 30 or so uses should not drain it too far, but it will power my 2021B Amp-32 based boombox for at least 8 hours, probably much more than that.
In addition to smaller size and less weight, the other advantage is really fast charging of half an hour or less. Once it's charged, the charger automatically shuts off. The cells come with an integral control board that prevents them from too-high discharge and (I think) other ways.
--Buckapound
http://www.batteryspace.com/lifepo4beltbagpowerbattery128v68ah8704wh14aratefastsmartcharger.aspx
I have been a little cautious about too much draining, as the first 30 or so uses should not drain it too far, but it will power my 2021B Amp-32 based boombox for at least 8 hours, probably much more than that.
In addition to smaller size and less weight, the other advantage is really fast charging of half an hour or less. Once it's charged, the charger automatically shuts off. The cells come with an integral control board that prevents them from too-high discharge and (I think) other ways.
--Buckapound
Your charger is probably too small for the pack. I can fully charge my LFP pack to 100% in 17 minutes, and to 80% capacity in about 5 minutes. The batteries don't get warm or anything. They are just incredible.
Pretty amazing advance in battery technology... Haven't seen it mentioned but I'm assuming that you are placing a fuse between the battery pack and the amplifier to protect against the admittedly unlikely event that the amplifier fails and the battery protection circuitry does not function correctly?
Well, most LFP cells have 1C charging capacity rating. Though some have much higher. So yours can handle up to a 6.8A charger safely. With your charger you should be able to charge from 50% to 100% in about 30 minutes as you wrote, and from 0% to 80% in the same time. From 0% to 100% would take around 2 hours though.
There are some non-commercially available ones that have very very high charging rates, up to 250C is being tested, that means from 0% to 100% in under 1 minute. These does require active cooling though so it'd mostly be for electric cars but that is the primary use area for these batteries. Imagine charging your electric car faster than it does to fill your tank with gas? The future is bright!
(Provided you could find a safe way to deliver 8000A at 380V to fill a 50KWh battery in that time)
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Well, I just ordered 6 LiIon cells from DX for my portable project with a sure ta2024 board. Are there any cheap sources available for LFP cells in decent capacity? The LiIon I got were like 6,75$ for 2 cells with ~2400 mAh. The LFPs I ve seen so far are all ~1100mAh. Would seem like they are not so killer then?
Plus new charger needed again :/ LFP=A123 right? then at least my balancer would work ...
Greetings rob
Plus new charger needed again :/ LFP=A123 right? then at least my balancer would work ...
Greetings rob
I also have some of these LIFePO batteries that I bought for powering 3.3V DACs, etc. I only just started to try them - have you guys been using them for long? Amazing current delivery (internal impedance of about 4mohm!). Great youtube vid of a guy jump start a car with 4 of these in sub-zero temp http://www.youtube.com/watch?v=qcvmvrmTMMk
How does the Tripath amp sound powered by these? I have a TA2020 amp which I want to use with these batteries - the only thing stopping me is getting solder to adhere to the base of the batteries for connecting 4 in series. I need a more powerful soldering iron!
There's a report of a visit to Audio Consulting in one of the on-line audio mags where he runs all his equipment on these batteries - amp, DAC, turntable, etc
How does the Tripath amp sound powered by these? I have a TA2020 amp which I want to use with these batteries - the only thing stopping me is getting solder to adhere to the base of the batteries for connecting 4 in series. I need a more powerful soldering iron!
There's a report of a visit to Audio Consulting in one of the on-line audio mags where he runs all his equipment on these batteries - amp, DAC, turntable, etc
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Ok, thats still like double the price. I guess maybe one could find them a little cheaper someplace else. I mean the 18650 Trustfire 2 cell deal for $6,75 (unprotected) is a killer deal too. I guess they are fine for my small portable project.
I'll consider the LFP for my next project, where size/weight is less high on the priority list.
Anyone know of a simple charger that is capable of charging LiPo/LFP (SLA would be nice too) at least 4s or so? Not too expensive, since I already have an rc-hobby charger for LiPo and everything (except LFP of course) and that thing is kind of bulky with AC-Adapter+Balancer+breakout for the balancer... I would enjoy a more compact solution!
Sorry if you feel the thread highjacked, but I guess it's still pretty much on-topic. If not, just say so, and I'll stop or delete the posts!
r0b
I'll consider the LFP for my next project, where size/weight is less high on the priority list.
Anyone know of a simple charger that is capable of charging LiPo/LFP (SLA would be nice too) at least 4s or so? Not too expensive, since I already have an rc-hobby charger for LiPo and everything (except LFP of course) and that thing is kind of bulky with AC-Adapter+Balancer+breakout for the balancer... I would enjoy a more compact solution!
Sorry if you feel the thread highjacked, but I guess it's still pretty much on-topic. If not, just say so, and I'll stop or delete the posts!
r0b
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