Custom built battery packs in Australia 10s4p 30Q Evolve upgrade or DIY

Hi folks! just a quick update, I’ll be ordering parts next month and building from early Feb. I will only have time for 2-4 per month until April/May ish and then ramping up production heavily through to September. Now that i have all the materials sourced i can keep good stock levels to avoid delays like I’ve had in the past! There may be slight increase in pricing due to our dollar sucking ass

Thanks for the excellent feedback @Wizzee, glad to hear its working well!

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Hey man, I am in aus and I recently over discharged by 12s pack. This might be a weird question but I need to get some cells from Nkon and I am scared I’ll get charged a shit load of import duties. What is your experience with customs and VAT, if you have ever been charged any could you let me know please.

Pm is fine if you want to keep it confidential, Thanks

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hey mate, theres no extra taxes from nkon. heres the version without VAT https://ru.nkon.nl/samsung-inr-18650-30q-3000mah.html

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Wow that’s great, I was a bit worried as in the final checkout stage it says customs charges and vat may be charged. That’s good to know. If I don’t get the cells I might hit you up for a pack

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Sorry to hear your pack got over-discharged and damaged, but would you mind telling what happened?

I was aiming to test out how far I could get on a charge with average riding as a bench mark for future rides. I was at about 40% on the battery gauge (previously this has been about 3.6v/cell) and went for a ride, it seemed kinda sluggish going up a very small bridge, I looked down and saw the display was at 12% (after about 1.5km since 40%) I thought my batteries must be about to hit the vesc cut off of 3.2v so slowly started heading home. I had to push the last 800m or so.

When I got home I tried checking my cells voltage through the charge port as usual and it wouldn’t read a voltage, that’s when I knew something was very bad as my bms cuts of at 2.8v/cell. I quickly pulled the case off and checked all cells the first 4 were at 3.2v but then two were at 2.5v and another 3 were at 3.6v and a further 3 at 3.4v. This imbalance meant that the pack voltage averaged out to 38.4v cut off on the vesc which thought all cells were at 3.2v.

I am now going to try and design a specially monitor for people that use charge only bmss that will beep or notify you when your battery is getting low, it will monitor individual cell voltages instead of the pack as a whole.

I will try to revive my pack but it will get repurposed as a portable charger/power pack as it won’t handle high currents very well anymore I don’t think.

Sorry @TinnieSinker for derailing your thread a little, I guess this could be some valuable info for some of your customers too though on what bms to use

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all good, strange that the cells where so far out of balance :face_with_raised_eyebrow:

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Might be some bad connections with high resistance between P groups?

Yes I guess that’s possible. I checked them yesterday and they had rose back up to safe voltages?!? The lowest was 2.98v all others were above 3.15v, I still refuse to trust them for high current applications though even though they charged up to 3.75v just fine and self balanced all within 0.01v.

I might just use it as a portable esk8 charger or phone power bank for when I go camping

Well I would just like to report absolutely no issues at all with my 12s4p from @TinnieSinker Going strong and still packing a massive punch right throughout the discharge cycle. Using a huge bestech discharge bms and working well. No cut outs or over voltage issues. Charged everyday for the last 3 months and ridden like it was stolen. Nice work Jai.

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do you normally charge up to 100%? i know its not recommended to prolong battery life but most bms’s will only balance if the cells go over 4.2v

Yeah always, I’d prefer to just charge to 4.15v but the bms only balances at 4.18 or something like that.

I also charged fully this time as I wanted to see how far I could get. Sometimes I just charge to 4v if it’s a short ride and stuff like that but usually every 2-3 rides I do a full charge to balance the cells

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Awesome service your providing here, knowing I can get a quality pack and I can get it to my door for $30 bucks makes me keen to start a new build.

I could save postage and just rock up with a 10 pack of fatyak cans to share for pick up!

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Cans? Mate it’s gotta be bottles or nothing

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Mate… he is the @TinnieSinker

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@Sippahodge @kalebludlow haha yeah no worries, I’ll sink any Yak👍

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Hoppy beers I find go well in a can! But I also drink Guinness draught and Kilkenny from a can.

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Didn’t even think you could get Yak in a can tbh

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How do I go about getting a 10s4p made for my BGT, and also where do I get the spacer from.

hey mate, remind me at the end of the month and i’ll whip up a pack for you.