This speaker Zoook Rocker Torpedo Bluetooth Speakers: Amazon.in: Electronics has 2x25w speakers with only 5400 mah battery which charges through 5v 1A usb smartphone chargers. I was trying to do the same. But the 18650 batteries (3.6V and 2Ah or 2000mah) available in market when connected in 4 series 2 parallel connection (giving 14.4V and 4A, 57w) is only chargable through a power adapter above 14.4V and 4A which are generally laptop chargers and not usb chargers. Guessing the battery of this speaker, it should at least provide 14.4V and 3A of power which cannot be charged through mobile usb charger. Is it possible to make same battery with usb charger for my project which only needs 2x22w at 4ohm impedence ? I know how to make battery with BMS, but dont know how to charge it through usb charger. I asked about it in other forums but everyone told me that a usb charger will take years to charge.
I can see how this boombox seems tempting..
Somewhere there is a boost involved giving more voltage from the battery, or more voltage from the USB charger to charge batteries in series.
But kinda funny how this 50W boombox can be fully charged in 4-6hours from a 5W source, and then play music for 8hours... I understand it is not 8hours at full blast, but still...
Anyways, you can charge series connected batteries if you insert a boost between your USB charger and batteries. Why only use 1A when USB chargers give you 2A? Some give 2x1A, and some have 2A outputs, either way you have 2A available. That's still only 10W and the charge time will be longer the bigger the battery pack.
I'm sure you can find some cheap boost, say one that converts 5V to 18-24V, then have a Li-po charger charge your batt pack. I hope you know the dangers with Li-pos and what to include to make it all safe.
Somewhere there is a boost involved giving more voltage from the battery, or more voltage from the USB charger to charge batteries in series.
But kinda funny how this 50W boombox can be fully charged in 4-6hours from a 5W source, and then play music for 8hours... I understand it is not 8hours at full blast, but still...
Anyways, you can charge series connected batteries if you insert a boost between your USB charger and batteries. Why only use 1A when USB chargers give you 2A? Some give 2x1A, and some have 2A outputs, either way you have 2A available. That's still only 10W and the charge time will be longer the bigger the battery pack.
I'm sure you can find some cheap boost, say one that converts 5V to 18-24V, then have a Li-po charger charge your batt pack. I hope you know the dangers with Li-pos and what to include to make it all safe.
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Yes. But say I have a fast charger rated at 12V and 2A. Will it then be possible to do such thing. See, the 18650 li-ion batteries available to me have 2200 mah which gives 3.6V when fully charged. Connecting 4 in series will give 14.4V and connecting same with another in parallel will give 4A total. So there will be no requirement of step up from battery to amplifier. Trick comes where charging is. Available usb chargers available in amazon are all 5V and 1A max. Zoook Torpedo has the same. But if power is taken from usb charging module to step up converter, then output power max will be 12v and .8A... Which is too low of current for batteries to charge. Any other possible alternative ?
First: you can charge at any current you wish. Up to the batteries max rating. Just cause the batteries say 2A doesnt mean you must usx 2A.
Second: The battery's nominal (kinda like average) voltage is 3.6V. But they need to be charged to 4.2V for them to be fully charged. So a 14.4V pack is charged to 16.8V.
Second: The battery's nominal (kinda like average) voltage is 3.6V. But they need to be charged to 4.2V for them to be fully charged. So a 14.4V pack is charged to 16.8V.
Got it. But the battery has to give output of 14V and 3A and has to charge with a usb charger of 5V 1A. One option is to connect 4 18650's in parallel giving 3.7V and 8A and use a step up to supply 14V and 3A to amplifier (if possible. I dont know please help) and use a the usb charging board which will supply 5v 1A to that 3.7V 8A battery.
Another is connect 2 in series and 2 in parallel giving 7.2V 4A which again have to use a step up to provide 14V and 3A to amplifier. But this time the 5V 1A usb charging board must also be connected to a step up to increase voltage to 8V or 9V to charge batteries. Please tell if its logical and possible...
Another is connect 2 in series and 2 in parallel giving 7.2V 4A which again have to use a step up to provide 14V and 3A to amplifier. But this time the 5V 1A usb charging board must also be connected to a step up to increase voltage to 8V or 9V to charge batteries. Please tell if its logical and possible...
Yep. If you only have a 5V source to charge with, somewhere you'll need a step up converter.
If you parallel batteries for high capacity 3.6V, you will need to step that up before the amplifier. If that step up is noisy in some way as to create noise in the audioband, you will listen to that noise.
If you place batteries in series so only batteries are used when listening to music, the amplifier will be dead quiet.
When you are charging you may not be using the amp to listen to music so it wont be so critical if the step up for charging is noisy.
You will probably find step ups and chargers and BMS on ebay or banggood or whatever. You always get what you pay for, and the main concern dealing with Li-ion or Li-po batteries is fire. Make sure the BMS is up to the job.
Btw, dont worry so much about max current. You are not going to run the amps near clipping. Most likely you will be running 1-3watts for 95% of the time. The drain will likely be in the 0.1-1A per channel. Besides, even tho 2A is max contious drain, you can pull many times that for short periods.
The capacity in mAH is more important, the more the longer they will last. My undestanding 18650 cells on ebay are mostly fakes and don't have near the specified capacity. I dunno, might be wrong. But make sure you buy from a proper honest source.
MMy plan for a boombox is to use battery packs meant for RC airplanes. They can deliver 10s of amps, are available in voltages as high as you want, and hve built in BMS. But I do not plan on limiting myself to USB for charging.
If you parallel batteries for high capacity 3.6V, you will need to step that up before the amplifier. If that step up is noisy in some way as to create noise in the audioband, you will listen to that noise.
If you place batteries in series so only batteries are used when listening to music, the amplifier will be dead quiet.
When you are charging you may not be using the amp to listen to music so it wont be so critical if the step up for charging is noisy.
You will probably find step ups and chargers and BMS on ebay or banggood or whatever. You always get what you pay for, and the main concern dealing with Li-ion or Li-po batteries is fire. Make sure the BMS is up to the job.
Btw, dont worry so much about max current. You are not going to run the amps near clipping. Most likely you will be running 1-3watts for 95% of the time. The drain will likely be in the 0.1-1A per channel. Besides, even tho 2A is max contious drain, you can pull many times that for short periods.
The capacity in mAH is more important, the more the longer they will last. My undestanding 18650 cells on ebay are mostly fakes and don't have near the specified capacity. I dunno, might be wrong. But make sure you buy from a proper honest source.
MMy plan for a boombox is to use battery packs meant for RC airplanes. They can deliver 10s of amps, are available in voltages as high as you want, and hve built in BMS. But I do not plan on limiting myself to USB for charging.
Right. But the speaker Im making is just 2x22w 4 inch speakers. So the box will be super portable. My plan was to make it usb rechargable just as the speaker I mentioned -'Zoook Rocker Torpedo'. As I will take this speaker to various places, I wont be able to find suitable charger for the battery pack like a laptop charger everywhere as I live in India. Usb chargers have same output voltage and current almost everywhere so it will be more convinient to take it everywhere. Plus if I manage to get laptop charger for this speaker, most probably the pins wont match and charger wont fit along with huge difference in volt and amps than my battery will require.
I want to make the same battery as zoook speaker, providing 14V and 3A and charges with 5V 1A usb, only then it will be possible for me to build this speaker.
I want to make the same battery as zoook speaker, providing 14V and 3A and charges with 5V 1A usb, only then it will be possible for me to build this speaker.
Another idea.. I could make a 3s 2p giving 10.8V and 4A (42W) which will be more than enough to drive these speakers. I will use 5V 1A usb charging module and a step up to convert it to 12V and 0.8A which will charge my 10.8V and 4A battery. Will this be possibel ?
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