Hi yeh, those Turnigy ones are the ones I’ve had in mind for LiPo’s for a while, but they’re what I mean when I say ‘out of stock or discontinued’. Hobbyking doesn’t have any 6s in stock, and other stores have them listed as discontinued. Amazon seem to have a couple for more money, but the seller is hobbyking apparently so I’m not sure that’s an accurate listing lol.
I’ve sent a couple pm’s to people in the UK who apparently have a lot of battery building experience, so I’m going to get some info about what’s recomended and the best way to get a pack built and wired up, and then I’ll report back when I figure out the option. Also looking on the used forum in case someone is already selling what I need!
Oh, for some reason mine had defaulted to ‘global’, and it was out of stock. But you’re right, UK shipment is in stock. That might well be a good option then, if I can figure out connecting up a BMS etc. Time to find a guide!
(I would prefer to figure out a tidy charging/switch solution, than having seperate charging for each battery and having to disconnect and remove them every time. Just the way I am.)
It’s not a big deal to wire up a bms.
Just depend on the bms you choose. If you need help with it, just post what you choose and we can help you with wiring everything up.
If you don’t know yet, you have two options: to get a bms for charge only or charge and discharge. Both have advantages and disadvantages. If you look for a good bms than google for bestech. They make some good ones.
One thing to consider with bms and lipos is that you should minimize the time the packs are fully charged. Best would be about 3.8v per cell when ever you don’t use the packs. So best to drain your pack till that voltage round about and only charge it up befor you go for the next ride. Don’t let the pack sit for 2 or more days fully charged. That can pretty fast damage your packs.
Hello again everyone, I’m back armed with much learned information… which has mostly led to even more confusion! Huzzah!
I hit some constraints in my build when I realised that when I transport it it will need to fit in the boot of my car. This gives me a max board size of 36" (maybe ending up with a 33"). So I’m cutting back on the ‘all terrain’ and making a slightly more sensible somewhat-compact build (still using bergmeisters or similar).
So
I’m still concerned by batteries. I would certainly still want decent consistent braking, which I believe is based on the max-charge rating of the battery? Which is quite low for li-ions. It seems I’ll be needing 4s or 5s to get reliable braking with li-ions, meaning I’d probably end up with something like 8s4p or 8s5p. (I could up it to 10s, but I believe that only gets me additional speed, and I doubt I’d even go over 15mph anyway (8s should get me to 20mph, according to loaded calculations).
With Li-Po, I can get a higher braking ability (that is, if the way I’m working it out is correct, the search on this forum has been very vague on the braking front, I honestly don’t think people on here use their brakes much :P) even with a 1p battery setup. Which means I could go for something like an 8s2p and all I would lose out on is range (but it seems like I’d have enough for my purposes). And if I plan my space I could probably increase to an 8s3p in the future.
Actually, because lipo packs are quite a lot thicker than liion, and my board is small, it’s possible I’d have to go with 3s packs instead of 4s (because the 3s are thinner). So 9s2p would be the easier config. Unless I have enough room for a bunch of 2s packs, but I’m pretty sure using 2s will limit me to 10s1p.
Does this sound about right? Or is dropping from a 10s losing me more than I am thinking? I’ve been told a couple times that 10s should be my minimum, but I’ve not been given any actual reason why that would be haha, and the only difference the maths is giving me is top speed. (and some range).
Basically need sanity checks on this. I’ve ALSO been told that I should totally avoid lipo because it’s dangerous and liion is much more reliable. And this is from people who are quite highly respected on this forum, so I’m really wary of throwing my eggs into the explosive lipo basket. I had a great offer on a 10s5p battery setup with BMS and everything all thrown in, but unfortunately I don’t think it will fit on the board
Thats the long part out of the way. The shorter one:
I still need to figure out a BMS and a VESC. I know all the different types now, and I even know the differences between some of them. But the Dual VESCs like the Unity and Flipsky are very expensive and/or not available until some unknown date. I could get two single-motor VESCs, but I’ve had some trouble finding one that didn’t seem like a knock off. Much the same with BMS… the two I’ve found from each end of the spectrum is either Bestech (good but expensive) and the Dickyho BMS (waterproof and cheap and… reliable? maybe?)
Have been scouring the used parts forum, so hopefully something will pop up.
Originally it was a tongue in cheek “£500”, which I think I wrote somewhere but I don’t know where. But I also did say I knew that wasn’t going to happen lol.
Budget is as cheap as I can, while still being decently reliable and nice to ride. I’m using it as a project piece, teaching myself some new skills etc. Hence I am planning to build a remote from parts instead of buying a premade. I also bought myself a 3D printer recently, and this will be my first big project to involve it. (Things like a custom NESE module, enclosure prototyping, etc)
So budget is… I mean as cheap as I can get it. I’m happy to sacrifice speed, as I’ll barely ever go faster than like 15mph anyway (if that), but reliability and safety (brakes and battery wise) are more important. I’ll call it £800 to put a fairly realistic figure on it.
EDIT:
ALSO! I just read your name… I think I just read like 100 pages of a thread with you in it, where you had customised someones NESE module variation! Winfly maybe? Your version was really nice as I recall, I think I sent a request for google drive access to nab your schematic haha. (if that was you)
When I say make a remote, I don’t mean from scratch. I’m going with one of the ones from here, with plans and part lists and everything, I’m just assembling it myself and 3D printing the enclosure. That’s a future upgrade project though, for the short term I’d pick up something standard.
Winfly did mention he may release his designs, but only after he’d recouped some of his R&D spendings (which is perfectly valid, as he spent a lot of time and effort on coming up with a slimline alternative to the NESE). But before I go too far down that road I need to be sure I’m actually better off with Li-Ions in my build.
No problem! I only brought it up because @mishrasubhransu posted here and I recognised the name haha. I hadn’t even heard of NESE before today, and then I found your thread and it gave me a lot of ideas for more uses for my new 3D printer
If you ever do release your blueprints I’ll certainly be interested
If you feel like it take a look at my “basic pneumatic board” build thread to get a sense of relatively inexpensive all terrain build. If I were to do it again, I would replace the motors, mounts and trucks with a all terrain pneumatic kit from dickyho.
I’ll take a look thanks!
Yeh I’ve already spoken to both Dicky and Timo, Timo has been really helpful with sizing things up and giving some advice. Dicky’s mount/truck/pulley kit is saved on my list, though I hadn’t considered his motors… They seemed pretty cheap, and I had a pair of sealed/sensored maytech 170kvs saved as a good setup. But maybe I should give Dicky’s a second look, as I’m unlikely to get them particularly wet… grit and sand might be an issue around here though (even on the paths/roads, I live on the coast)
Personally I don’t think lipo is more dangerous than lion in esk8 application. Both have their plus and minus on safety.
When your building a lion pack there is way more ways it can short it self out and make a fire then just a few lipo packs hooked up with XT plugs. So lion requires much higher battery building skills before it can be considered safe in this application.
Lions explode like mini rockets if they ever get into thermal run away. while lipo “only” shoots foot long flames out the side but generally stays in one spot.
Both will burn up if over charged, lions should be a bit more graceful at this.
If you beat an individual cell with a hammer lions are better at this kind of abuse. But that is just single cell not a large multi cell pack.
There is 3 main ways to make lipo catch fire. 1. over charge 2. physically penetrate with something conductive 3. over discharge/current into thermal run away. But I don’t think that would be possible in an esk8 unless you used a way way undersized lipo.
For lion the main thing I have seen is thermal run away while ridding the board, probably cause by short circuit from pack construction error / heavy vibration environment of an esk8.
Let’s get back to this post.
There is nothing bad at all with 8s.
The only argument I could imagine is, the higher the voltage the lower the current, buut than again the higher the voltage, the faster you drive which means you need more power, which result in higher current draw again.
Don’t worry about the braking current. I would more worry about the voltage sag if you use a LiIon pack below 3p.
If you brake you don’t brake for 1h constantly.
If we look at a 30q cell the fast charge rating is 4a per cell for a full charge cycle. If you brake for 20sec that current can be slightly higher without to damage the cell.
Also consider that some of your brake energy is used producing heat and magnetic fields.
If you want to go as low as possible I would recommend you to have a look at the Sony vtc5a cells. They 25a cells (rated in the data sheet even at 35a) and a 8s3p or 4p would be ok.
Just don’t expect super power and endless range.
If you want a budget remote and happy with trigger style, than get a gt2b and print your own case like the sparkle. That’s 25€ + the filament and 1hour for getting all together.
If you want to go budget vesc than have a look at the hw4.12 vescs. I think people have found the Flipsky 4.12 on eBay for 50€. I would than definitely add one of the full enclosed heat sinks on them to get a good performance out.
Something like this
You can get those for sure also on eBay for cheaper.
While you’re right that they’re probably both pro and con in safety aspects, I’ve just gone through some calculations and for a roughly equivalent battery setup between the two, for the size / weight / price of the battery, liion seems to come out ahead. Lipo has much higher discharge and charge rates (but apparently I don’t need any higher charge rate for safe braking?) but they seem to be overkill, and the liion gives the same speed and greater range.
Considering I have space and weight restrictions, (and limited budget) liion seems to come out ahead. As long as 8s4p is enough power. (even 10s4p might fit, but 10s5p I think will be too much)
I had looked into other cell types, but the 30q seemed universally recommended as the best option.
I had seen those older vescs on ebay but wasn’t sure if they were worth risking. Hasn’t there been a lot of updates to the software since then? I assume 4.12 was old compared to 4.2 and 6.6, but I was assuming it referred to software versioning and maybe it doesn’t.
I think off-road might be overstating things, I’m talking grassy parks and gravel mostly, not mountain trails and corn fields. Though maybe I need more discharge even for that, I honestly don’t know as I’m unable to test until I build aha.
Edit: I mean the full mtb builds (that don’t use lipo) seem to use somewhere between 10s4p and 12s5p, which either has the same 60c discharge rate or is slightly higher at 75. Lipo is the only way to get a big boost to 200+, but that doesn’t seem to be a requirement going from the build logs…
The 30q is recommend as they have a high capacity and a high discharge. For a 4p plus pack they outstanding the best 18650 cells for esk8 for now.
As soon as you go 3p or less or 5p and more there are other cells which may fit better or are cheaper.
That’s why I would rather recommend the vtc5a for a 3p pack if you can accept the 500mAh less capacity per cell. If I remember right the price for 30q and vtc5a on nkon should be pretty similar.
About the vesc, you mixed something up between hardware and software.
You can run also the newest vesc sw on a hw4.12 based vesc.
Sure there have been made some improvements from the 4.12 hw to the 6.x hardware and I‘d rather would go with a hw 6.x based vesc than a 4.12 if I have the choice, but it doesn’t mean that the 4.12 is a bad vesc version. Especially not if you on a budget.
I wouldn’t recommend to buy any 4.20 vescs. The once you get for now have pretty much faults. So as you can see, not every new hardware version need to be an improvement.
while lipo “only” shoots foot long flames out the side but generally stays in one spot.