Sure that was my plan - I was only thinking if I also have to add some cooling fans but this would have increased the size… So I guess I will try without fans just with the exposed heatsink.
Decided to use this to turn off and on
Should do the job
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you won’t need fans no way. I’ve pumped 9a through one of these with no fans and it got pretty warm but was fine. at 5a you don’t need a fan no no no 
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I’m pretty sure step up converters don’t do well stepping up to such close voltage differences-, like 12S to 12S charge voltage.
Is this what you said you were doing?
I’d recommend 8S, maybe 10S as supply so that it can effectively step up voltage to 12S. Everything else sounds great to me.
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nah it does it fine. it essentially acts as a pasthrough at first, then as the voltage goes down, more current is pulled to get re desired voltage
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I think thats the beauty of a switching converter… there is no real “deadzone” or “dropout limit”. Depending on the efficiency you might only lose some % on the output side.
So I also think it should do fine
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Two first parts already arrived…
The Step-Up Converter and the Wattmeter.
I was able to regulate to a stable 50,4V even with my lab supply ranging from 8-17V for the first test run… seems very stable.
As soon as I get my battery I can set the current limit and then there is only the BMS and the case missing…
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Printing the bottom and top part of my 12S2P battery holders… the amount of batteries per line is optimized to the PCB width to make it as compact as possible
Also designing a case to put everything into… with a proper hole for the heatsink and the displays as well as the power on button…
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nice man, this looks like it’s coming along well! I’ve just ordered a 4a 6s charger and another Buck converter so I’ll have my 3 extenders all running! lol. i wanna do a 60km ride in one go around my area soon!
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whats the smallest 48 volts power supply out there?
since power supplies are adjustable could I get a small one, up the amperage to double, and make some kind of water cooling contraption that could be filled with cold water found at the coffee shop I stop at? they seem limited by heat dissipation more than anything.
@hummieee
Not sure what you want to achieve with this solution? Are you still talking about a battery powered charger?
Just printing my case now… some first fitting updates later
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Is that octoprint? Never seen that GUI before
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I feel like what you have isn’t really a charger but a backup battery you slowly feed into your regular battery. to each their own and it suits what you want and fun to do but…what about an actual portable charger? the weight of that extra battery and step-up thing probably weigh more than an actual charger that would be doing more amps.
ive been looking on endless-sphere at the mods they’ll do to power supplies adjusting voltage or current. sadly they’re almost always dropping the current to keep them from breaking, but I think they’re breaking from heat and not amps specifically and id rather increase the amps they will put out, and figure a manual cooling method with cold water at the coffee shop where i’d be charging. a tiny high power bulk charger for going long distance and stopping maybe 30minute stops at coffee shops to charge is the goal.
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Well actually I am not sure what you are referring to. It is a charger… It has a source… a PCB that regulates voltage and amps and a load (the battery) and it does exactly the same thing that a charger does (it also has a BMS). And I don’t understand what an “actual” portable charger would be ? I am going up steep mountain trails above 1500 meters - there are no coffee shops up there - there is absolutely nothing up there as a matter of fact 
EDIT: Also I am not sure if the use for my Portable Charger came across clear earlier.
I need it for my mountainboard… I can do around 20 km and 700m Altitude… my goal is to reach 1100m Altitude to reach a nice viewpoint on the mountains… thats the whole idea why I need this “portable battery charger” based on a battery
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Very nice! What is your octoprint setup for the anycubic? How is that camera mounted? 
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@Zach
I just use a raspberry pi with OctoPi actually and some samba shares to transfer over the network… the camera is mounted on top… I had a moving camera on the BED but since this cam is on all the time and I like to run around nakes at home I changed the camera position… HAHA
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Ok I understand. No coffee shops around. I have a coffee shop like every quarter mile and want to use their power…and water to cool my overpowered power supply.
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