oof, says that one is currently unavailable
but I found this that looks similar, what do you think? Also, you just using a voltage display in parallel? Or what is that fancy display. I must have it, lol
The current can be gotten/assumed through ohms law based on voltage and resistance alone. I forget what it was in that instance but a lot and not even warm. @janpom.
yep, same thing there … not sure the quality of that one but I’m sure it’s probably okay. if it works on the bench, just make sure to pot the coils and mosfets and stuff… I used glops of e6000 to pot mine.
For voltage I just got a voltage display, two wires hooked up to either the input or output (or both) depending on what voltage you want to see… I did the output since I mostly used power tool batteries and they would cut off when dead anyway and had their own voltage displays, and added on some low voltage beepers to other packs I put together to know when to pull them.
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I did something similar one time being lazy as hell, I was putting together a gigantic 1P pack for an experiment, half the cells were from a drained pack at like 3.2V and half of them were at 4.1V. Being lazy as hell I decided I’m just going to start slapping nickel on with no care to balance them. The 3.2v cells got noticeably warm, but never hot. Holding them was not uncomfortable at all, like lukewarm water hot. Never measured anything but it worked just fine.
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Great design! I’m curious why you made the battery mount in a separate piece than the boost converter housing. I’m thinking of making a similar design in 1 piece which would eliminate the external wires.
I also see you used two different monitors. Is there one you prefer?
Lastly, if you put a battery monitor on the output side would you be able to get a read on the onboard battery status?
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Thinking about experimenting with two 6S lipos as an extender to a main 12S4P pack with 18650 cells. In this case I would be connecting them in parallel.
Anyone has tried this setup?
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I would not recommend mixing different cell chemistries.
Also keep in mind you discharge lipos to 3.4-3.6V per cell max and LiIon to 2.8-3.2V per cell.
To not over discharge the lipos you would need to cut off at 3.5V per cell which will cut range from you LiIon pack than.
All in all it doesn’t seem to make too much sense for me.
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Yeah, I agree with all your points, the thing is I got the lipos from a friend and would be nice to make use of them instead of building another pack 
Why not just swap the packs out?
Drive your LiIon pack till it is empty, than change to the lipo pack and drive till it’s empty.
Why you need to wire them in parallel?
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I would rather do so but it’s a bottom enclosure with an anti-spark switch, that would not be practical.
Or have them connected in parallel until the lipos die, then disconnect and milk the liion pack.
Would wanna have a bloody nice and loud low voltage alarm on the lipos tho
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Still doesn’t feel right for me to play mix and match, but I don’t have technical arguments why it shouldn’t work if you take the right precautions.
Maybe @Battery_Mooch can give his thoughts on mixing different chemistry cells in parallel?
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Quinn just linked it 
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You said it all right here.
Nice work! Can you share the file for the xt30 cap? I was just about to make one this week for someone.
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Sure, here it is:
Just finished a 20 km offroad ride, worked really well. 10A was the max pulled from the extra battery, I’ll post more details soon.
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Ahh that’s an xt60. Looks so tiny next to that charge port!
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Yeah it’s a big one!
An xt30 should handle 30A continuous which is probably enough but I found the xt60 a good compromise between the xt90 and xt30 plus I had enough space.
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