Should be around 1.85kg once finished (not including the weight of the electrons when charged)
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Wired up the battery without the BMS and charged my other Board for a short time to see how it behaves.
Was able to set the current limit to 2A. However when opening up the limit all the way it maxed out at around 2.23A. I mean the charging pack is quite low on voltage and I was expecting quite a bit more worrying Amps but it seems it’s not really like that at all.
I will charge the pack and try again what the max Amps would be.
Considering this charging Amperage I consider going without a BMS for now (shipping might still take a couple of weeks on that).
However I wonder why the Amps are quite low 
The voltage on the output is set to 50,4V and of course increases as the “LOAD” (the longboard that I charge) will get charged more.
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this is looking so damn good! Like @hummieee said, yes they are limited by temperature. i used a 5s lipo to charge my board at 6a and it literally heated the heat sink up so much that the fets on the sink melted. it sent the pcb into a permanent short, so my input meter was measuring 1a draw without a load. Learn the limits of the boost converter and dont exceed them. I’ve learn the limits almost and gone through about 6 or 7 of these now lmao
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My heatsink does not really get warm actually.
I had to replace the trimpot for the current limit setting because it was broken at first.
I will charge my SOURCE Pack up today and see how much Amps a full pack can deliver and then I will settle for a convenient middle Amperage.
I was aiming for 4A but even if I can’t go over 2-3A it’s still better than nothing.
At the moment I don’t really see the necessity for my portable charger to have a BMS.
The SOURCE pack will never really have high discharge currents and it will always have a stable continuous charge / discharge cycle.
I will evaluate how low I can go with my SOURCE pack safely and try out the Low Voltage setting of the PCB (however I am not sure if it cut’s the power or just reduces the amperage ?)
you’ll be able to get 4a out of it very comfortably. any less and you’ll find it won’t charge fast enough to top up your board while riding.
Regarding this, if you just use a bms to discharge, it will automatically cutoff when the board hits low voltage. rather than you having to watch the volt meter as you ride to see when it gets to a certain voltage. honestly just get a cheap bms. the supower 30a ones are great and just fine
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I already ordered one but shipping takes so long
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yeah that’s true. try holding out and use it with the bms.
also what did you replace it with?
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With a Trimpot of the Same Type W502 (5k).
However when I tried upping the Amps it will stay at a max of 2,3A which equals to 4,99k.
I wonder if I have to try another trimpot up to 10k but I don’t know how the circuit evaluates the current limit.
I just wonder because a 12S2P Pack should be able to push around 20A easily if the limit is lifted.
I want to do around 5-6A because I don’t want to charge while riding - I rather just sit down somewhere and let it charge by itself and then continue to ride up the mountain once finished.
Not really sure about the PCB quality itself - I mean the voltage seems quite stable but the current limit doesn’t work properly on mine it seems
So strange… with maximum current setting I am stuck at 2A… Checked the incoming amps on the BMS and it also says the same
Might really try changing the trimpot to 10k see if it can be pushed more… don’t really understand why though
I’ve had this too. i believe some arrive with defective current limiters. dont understand why either
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Damnit… 
I will try to trick the limiter with a 10k then… I mean the price is awesome and I would pay at least double the price for the same product without the flaws…
So you had this problem only on some PCBs and didn’t on others ? What was your Amp / Volt Range that you could achieve ?
correcto. out of about 8 units I’ve had 2 die and one arrive defective. I used a 10s battery to charge my board and charged (while riding) at 41.8v @ 5a. however i did have it set at 9a at one point and toward the end of the extender pack i found the boost converter getting very very warm so i toned it down. the source pack i switched off at 32v (which at 9a was drawing about 12a).
Also what in and output connectors are you using?
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I am using high Amp DC Connectors… I know its not as good as an XT Connector - but I am able to easily charge 5A - 6A with those on any of my other chargers…
So the maximum amps with the 10k pot is 3.5A… Not too shabby but maybe I will try a 20k on the next charge… It’s weird because it seems the current needs a couple of minutes to ramp up… not sure if this is intentional by design or just Chinese engineering randomness
Temp looks fine when charging 3.5A
the whole current ramping up thing i havent had yet. I’ve always had it go from 0-(set current) straight away. good you can get 3.5a though. where are you getting these trimpots?
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I am a DIY guy… I bought a whole range of them for my modular Synthesizer Projects back in the days… you can get them anywhere… mouser, arrow, farnell, eBay, AliExpress. However it pays off to go higher quality on those because they should be precise
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Regrading the BMS - I feel comfortable doing a couple of testruns without a BMS considering that the PCB also is fused and current limited.
As far as balancing the charger goes - I don’t worry too much because especially with only 2 parallel pairs I should only have around 0.02V drift and since this pack always “has it good” with no real hard charge or discharge cycles - it should work out quite ok.
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