It looks interesting! Thank you for the link 
I will definitly consider this method.
if you made it one cell thick and flat it would suit our needs more.
Yes I have used the quad 18650 holders and they are fantastic! They take some work, but not a lot of technical know how, and are well worth it in the long run. You have to do a little soldering and some epoxying, but itās really very quick and easy cause you donāt have to worry about over heating any nearby electronics or burning up your cells, or getting glue on anything real important or visible. Itās both a pain in the ass to spot weld them and you definitely donāt want to apply the heat of soldering them. Then there is the issue of ādriftingā and the potential of series packs and/or cells carrying differing voltages for various reasons (one being a bms going bad and mis-charging series packs, which has happened to me) and to find and replace those packs and/or cells you have to dismantle the entire battery pack, which is usually well put together and quite difficult to dismantle. Bam! Thereās those wonderful cell holders. You can access, test, and/or replace every single cell in your battery with ease. An absolute godsend with the expense and risk of 18650 cells. All it took for me was having a bad $30 bms destroy random series packs in my battery to be very grateful I had them, both for convenience and for safety at that point cause when some of your series packs are fried and wonāt hold a charge, the other packs can āburst dischargeā into those dead packs which just discharge current and that causes heat, swelling, and possibly exploding. Itās expensive and dangerousā¦ Anyway, I made a 10s8p with the quad 18650 cell holders. INOT the ones with the wires already attached. The wires are way too small to carry that much juice. What I did was to epoxy the holders back to back. There is an exposed part of each battery tab on the back of every cell slot that sticks down like a little nub so when u glue them back to back the nubs from each all connect at each end and I soldered each one so the ends of both packs were all connected. Then I took pure nickel strip and cut strips that were not quite as wide as the quad packs and pushed them down behind the four battery tabs and the plastic case so that all four tabs are connected. The battery tabs alone pin the nickel strip to the casing , even more so when you snap the cells in, so no need to solder! Having.already soldered between each of the packs, I then had a block of eight 18650ās in parallel and I made nine more for a total of 10 series packs of eight parallel cells. At this point, I epoxied two sets of five together, end to end, in two rows. I took 3/4" strips of nickel, bent them in half and pushed the ends of each of them in behind the nickel strips (that I already installed at the end of each pack) to join them in a chain. The two rows of five were then epoxied together side to side and at one end two 1 1/2" nickel strips (one on each the top and bottom of ONE end only) are pushed in behind the existing nickel strips so the two rows form a āUā shaped chain and so that you have the ā+ā and the ā-ā at the same end of the pack and donāt have to run a wire back the length of the battery Solder each of the 10 or 11 bms wires at the ends of each appropriate series pack, snap all your cells in between their tabs, single wrap of shrink wrap length wise and Shazam! You have a flexible, strong, solid 36v 10s8p lithium battery that is an accessible, customize-able, easy to monitor and diagnose battery you can be proud to say you built yourself. Did I also mention they are cheap as fill dirt? Oh, and did I say āI freakinā love emā? Cause if I didnāt, I meant to LoL Ps I can post or send you some pics if thatād help to see what Iām talking about just hit me up if you want em. .