Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Portable power box build
#1
I am currently starting to plan a portable power box using reclaimed 18650 cells . I am going to use it camping to power phone , charge go pro batt and tablet etc. Was going to incorporate a 24 volt inverter for other small 110 applications. plan to make a 7s 10p pack and use a DC to dc converter for 12 volt. I have started gathering and testing cells but need some info on how to charge pack, what bms is good but affordable, and anything else that I'm missing. I've done some research but most packs and so much bigger or smaller it's hard to get reliable info. Thanks for any info robert..
Reply
#2
I’m literally building something identical to what you just mentioned… less the inverter for AC power because don’t really have anything AC when I camp.
 
It is a similarly sized packed, using a 24 to 12v 30A Daygreen DC-DC, and a few other goodies like a Victron solar charge controller… I do like it has a programmable load output which I can use as is, or in conjunction with a relay if I need to management higher output loads.
 
For the BMS I will be using one of those Bluetooth BMS units.  I have not don’t extensive testing yet but the overall setup looks pretty decent.  Its certainly a lot better than something that does not provide any insight or monitoring capability.

Cell 5 is intentionally out of balance, which I used for testing.


Headrc likes this post
Reply
#3
(03-21-2019, 09:36 PM)Crimp Daddy Wrote: I’m literally building something identical to what you just mentioned… less the inverter for AC power because don’t really have anything AC when I camp.
 
It is a similarly sized packed, using a 24 to 12v 30A Daygreen DC-DC, and a few other goodies like a Victron solar charge controller… I do like it has a programmable load output which I can use as is, or in conjunction with a relay if I need to management higher output loads.
 
For the BMS I will be using one of those Bluetooth BMS units.  I have not don’t extensive testing yet but the overall setup looks pretty decent.  Its certainly a lot better than something that does not provide any insight or monitoring capability.

Cell 5 is intentionally out of balance, which I used for testing.


I am just "diving" into exactly the same one, and it is really completely filled with many features of Battery mamangement AND data aquisition !
1 kWp in Test
4 kWh battery target - plus Mobile Home battery
Ultra low cost
Electronics ? No clue. Am machinery engineer.
Reply
#4
(03-21-2019, 09:36 PM)Crimp Daddy Wrote: I’m literally building something identical to what you just mentioned… less the inverter for AC power because don’t really have anything AC when I camp.
 
It is a similarly sized packed, using a 24 to 12v 30A Daygreen DC-DC, and a few other goodies like a Victron solar charge controller… I do like it has a programmable load output which I can use as is, or in conjunction with a relay if I need to management higher output loads.
 
For the BMS I will be using one of those Bluetooth BMS units.  I have not don’t extensive testing yet but the overall setup looks pretty decent.  Its certainly a lot better than something that does not provide any insight or monitoring capability.

Cell 5 is intentionally out of balance, which I used for testing.



Will the BMS continue to charge the other cells even though Cell 5 is that high?

(03-17-2019, 09:17 PM)Kildragon6 Wrote: I am currently starting to plan a portable power box using reclaimed 18650 cells .  I am going to use it camping to power phone , charge go pro batt and tablet etc. Was going to incorporate  a 24 volt inverter for other small 110 applications.  plan to make a 7s 10p pack and use a DC to dc converter for 12 volt.   I have started gathering and testing cells but need some info on how to charge pack, what bms is good but affordable, and anything else that I'm missing.  I've done some research but most packs and so much bigger or smaller it's hard to get reliable  info.  Thanks for any info robert..

It depends on how you plan on using the portable power box?  Do you plan on adding solar?  Personally, I don't think Solar is the best application for power boxes designed for camping.  Anytime I camp, I seek out the shadiest areas of site. Also, panels are large and heavy.
Reply
#5
(04-09-2019, 04:38 PM)GMRedline Wrote:
(03-21-2019, 09:36 PM)Crimp Daddy Wrote: I’m literally building something identical to what you just mentioned… less the inverter for AC power because don’t really have anything AC when I camp.
 
It is a similarly sized packed, using a 24 to 12v 30A Daygreen DC-DC, and a few other goodies like a Victron solar charge controller… I do like it has a programmable load output which I can use as is, or in conjunction with a relay if I need to management higher output loads.
 
For the BMS I will be using one of those Bluetooth BMS units.  I have not don’t extensive testing yet but the overall setup looks pretty decent.  Its certainly a lot better than something that does not provide any insight or monitoring capability.

Cell 5 is intentionally out of balance, which I used for testing.



Will the BMS continue to charge the other cells even though Cell 5 is that high?

I am setting the balance to start at 4.0v per cell, so yes, as long as the BMS board can discharge and pull down cell 5 into balance with the rest, then it will eventually allow the rest of the cells to catch up and be balanced and charged.

Note: the BMS doesn't charge the cells, but it can stop the flow of current from the charger if parameters go out of range.  Those parameters are user defined.  Also, if the charge current is too high, it will most likely stop charging until cell 5 comes back into balance.

Unlike the super cheap BMS boards that only do a top end balance, I can make this one start sooner which is what I wanted.
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)