Is the bms charge only?
no, both of the batteries have a charge/discharge (on different ports) BMS
I’m now getting one of these guys going - right now the plan is a 10s5p flat pack (so its slim in bag, and spreads out the weight)
Bought this guy: https://www.amazon.com/gp/product/B07PVDY1V7/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1
Since @DerelictRobot hasn’t had issues with his.
Also have a charge/discharge 60A BT BMS for it.
I finally have a use for the 50 Samsung 25R’s I’ve been sitting on for like 2 years. Should add an additional 462Wh hopefully equaling additional ~8-10 miles of range.
I plan to make it so that I can disconnect the boost controller via XT90 or XT60 and then be able to hook it up directly to a Unity or some other ESC and use the backpack battery as a stand alone battery to power a board with just a drive train hooked up to it.
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Great minds think alike! what are you thinking for an enclosure? I was thinking of doing something similar with one of them harbor freight knockoff pelican cases
make sure you build a BMS bypass connector into it so you don’t have to discharge through the BMS when it’s powering a board 
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so I wana make it a flat layout so 10cells wide by 5 cells high, and I want to sandwich that between two pieces of ABS plastic for rigidity (or at least hot glued to one) then shrink wrap that then mount the BMS/Booster on top of the ABS with its own shrink wrapping.
gotta play with it though, but that’s whats in my head.
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oooohhhh … so the backpack is still useful whrn its a charger AND you can tape it under any deck? sick
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didn’t think of that part of the benefit but yeah!
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@klaus79856 i really want to put one or both of your 10s5p Samsung 50e packs in this Goliath phone charger.
Reply if nein.
@DerelictRobot the solar charge controller PCB sleeps on in storage. For now, golf cart style 48v to 12v step downs does the conversion work to make a decent 12v output.
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I assume that is a 7210A without the metal?
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Thanks @Fosterqc i was already planning to convert my backpack into a mobile charge station and this thread was super helpful! Ill be going back here for more info many many times.
My plan is to have a dc-dc converter, or maybe a few if need be, with an xt90 input and several outputs at varying amps with all the common charge ports and maybe a usb and a type c output as well, built into one or more boxes spread around and sewed into my pack. Then, i can use most packs as a backpack range extension, plus charge other devices on the fly, or make adapters for any batteries i cant use… it just sounds great to have a mobile electron directing station. And when my mtb is done i can just detach its peli case and throw it in my bag to extend my street boards range. Theres no downside.
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No idea, I bought it as 600W booster, almost like this one but not quite the same
US $11.59 40％ Off | DC/DC Boost Converter 10-60V to 12-80V Step-up Voltage Regulator 600W Auto Power Supply Transformer Adjustable Output Volt Contr
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I recently watched @TheBoardGarage’s video about a One-wheel accessory that has an interesting feature – voltage matching!
From their website:
- Voltage matching. when connecting two different battery pack together, you have to make sure they have very close voltage level, if you conncect two battery that has big difference in voltage , a surge of current will flow between the two packs and damaging your BMS in side the original battery. The PMS inside GT40 does voltage matching automatically by comparing the internal and external battery level 600 times per minute, and it decide wether it is safe to feed power into your board, if it is safe, the PMS will establish a connection between the external and internal battery pack by turning on a high speed switch inside, and showing a flashing green light on the indicator. If the voltage of your board is below safe limits, the PMS will show a blue light and you can connect your board to the charger until the PMS turns green. If the voltage of your board exceeds the safe limits, the PMS will show a red light, you can go out and ride your board with GT40 connected and the PMS will automatically establish the connection once the board is within safe limits.
This sounds awesome! It would mean never having to worry about your batteries being at unequal voltages when connecting them in case you forgot to charge one / your BMS messed up. And because it doesn’t do any voltage converting, the PCB doesn’t take up much space or power.
Anyone know if there are ready-made solutions for this that we could use? Build an external pack, add a module like this to the output – boom! Smart external range pack! Or do we have to ask someone like @SimosMCmuffin to design one for our needs? 
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This one popped up in a chat the other day…many monies.
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What’s in there? An inductor?
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I haven’t the slightest idea. @Battery_Mooch elaborated on it a little in the battery builders telegram a few days ago
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Where would I find a link to that?
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You would need to be a proficient/prolific battery builder and/or be invited…
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Awe damn if it’s a special secret club like that I’ll never be “invited”.
FFS
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150$ and it doesn’t support regenerative braking? Laaaaaame 
Pssst @glyphiks add me to the chat plz 
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