I now have a small pile of good-to-certainly-bad Gen3 modules... and a shiny new SkyRC B6 Mini charger/discharger. A few questions: 1) Is there ANY non-zero power setting that's safe for charging without compressing modules? (If so, what is it?) 2) I need to do this outside the normal 28-module pack. Any idea how much compression is sufficient? - 50 lb of stuff laid on top? - 100 lb force in a few places with clamps? - 2x6 wood clamped in place to get uniform pressure? - wood not good enough, so get (thick?) metal sheets? 3) Is there ANY charge / discharge power setting that's safe without extra fans/airflow? (Assuming proper compression) 3a) Perhaps with temp monitoring... keeping it below NNN? THANKS!
Look if you look at the plastic ends and the 12 mm bolts and the rods that hold everything clamped together I would think clamping between 2x4s or 2x6s and a regular carpenter clamp run up to touch and give an umph should get it You shouldn't have to squeeze it till it squishes You're just trying to hold it so it doesn't expand under charge and discharge cycles we're not trying to kill it it's only squeezed between plastic and other modules to begin with so I guess if you wanted to you could check with let's say a dollar bill and see if that will fit between the modules when they're clamped and then try feeler gauges they come way down to even thinner than a dollar bill see if anything will even get in there and then try to clamp to that use that feeler gauge to rack up four modules eight nine whatever and put that fueler gauge in until you have about the same force I mean it doesn't have to be any kind of exact torque or anything You're just trying to keep them from expanding from where you clamp them
You don't need pressure per say, you just need to prevent expansion. Some clamps and some plywood will be fine. Not that much force involved. You're just adding structural stability to the thin foil sides.
Thanks, @PriusCamper... of course "prevent expansion" all depends on how much pressure/force the module can create while charging (or discharging?) Related mini-story: Where we live in CO, it's well known that Bentonite clay soils can exert expansion pressure well over 10,000 pounds per square foot! Must remove if found. (That's why they dug a huge hole where our garage was to go when building... of course no basement under there. Just soil that would have wrecked the foundation and garage floor...) Two Key Questions remain 1) Is the expansion an issue during both charge and discharge? 2) Is a fan necessary even at the low amps used with hobby chargers? (0.3 to 2.0 maybe... mayyybe up to 5 although that makes me cautious)
If you have test module(s) you can charge it 350 mA for a few hours and get voltage and temp readings when you notice the module(s) start to swell. As the module(s) cool the swelling goes down close to before the charge started, but some have reported trouble getting modules clamped back into the packs case. Testing modules at 40° F ambient temps will have much different results than if tested at 80° F ambient temps. Much like PriusCamper, TMR-JWAP has done a lot of module work, TMR-JWAP 's CQ3's are most likely a bit different than the skyrc's setups, making it harder to determine the best way to setup cycles for what you have in the way of modules to work with. For module reconditioning the charge and discharge settings on the hobby chargers never made any sense to me just reading about them, and from my experience with pack reconditioning. Maybe this post will make as much sense to you as it does to me when I read it. New Prius, Battery Recondition Idea After Reading Forum ALL DAY | PriusChat
There's people on here who have argued that you can charge modules briefly when they aren't clamped down with no issue... It all comes down to heat. The expansion is going to happen when it heats up.
I don't see what's so hard about racking them up either in the case or between two clamps I should be like easy peasy just take a second and you just want to clamp them up gently so they can expand You don't have to kill them
FWIW, wrapping up this thread, I now have more insight than when I began. Modules only swell while charging. Discharging has never caused swelling in mine You do NOT want the modules to swell. They lose integrity 2x6 wood at each end holds things nicely A wood pipe clamp (especially if flexible in length, with iron pipe as the core) is easily strong enough for anything
I have several of the white plastic end pieces from module packs. Combine that with 4 pieces of 5/16" all thread and nuts. You can clamp however many you want. A fully discharged or partially charged module can take a decent amount of charge without swelling as long as you keep the charge rate low and don't generate heat. A good module that is in a low energy state should be able to absorb 2-3000 mah with no clamping or cooling air.
