Rebuild of my old board (V2)

DIY Builds
#1

V1 first build:

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Most of these plans described below have been scrapped, but I will keep them here to reflect cause the build has changed so much and it’s cool to look back on
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V2 build:
:wave: Hey guys, I’m trying to figure out what to do for the enclosure on my aluminum deck… It has a built in ‘rail’ system and I’m planning to utilize the rails rather than drill into the deck and I wanted to know what materials and enclosures/battery building techniques you guys might use on a deck with a little bit of flex… seeing as most of you have much more building and testing experience under your belts… I was thinking of using kydex or a similar mold-able plastic to make my enclosure but none-the-less I need some ideas

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DECK ^
Its a 42" drop deck… so the enclosure would need to be low profile and offer flex to accompany the deck. I don’t have a big battery at all, so extra space is not a very big worry…
I don’t have a welder or a setup to braze aluminum, but I do have a 3d-printer for specialty parts. I would like to avoid making the whole enclosure 3d printed, due to its lackluster durability and overall cost, but it is available as one of the few tools I do own to make brackets or inserts of kinds, and maybe even hinges… but I’m getting off tasks.

As I was saying, a plastic enclosure, possibly molded like that of one of the slick revolution boards

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Or maybe a hybrid metal/plastic or rubber flexible membrane between the battery compartments.
And if anyone has any experience with building flexible battery packs, I would like to get advice on how to build my new pack… I also don’t have a spot welder, so I need an alternative to fashion my new battery together. (probably a 10s2p or 3p without a bms, or maybe even a 12s2p and one of the neoboxes once Jeff starts taking orders :drooling_face:) I plan to make the battery removable from the board in case of warm temps or possibly situations that could cause damage to the battery… Just throw ideas, i’m not particular in what you message me.

It shouldn’t be hard to make, but I’m dipping my toes into the forum here to test the waters and get a feel for the community and your creativity :smiley:

also one more thing… how do you pad your batteries in the enclosures, and would a fan or intake system be a good idea?

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#2

Okay, lots of info to unpack here, so I’m gonna skim and throw out suggestions for each point you raised, more or less in order.

  • rails. Great idea, possibly problematic implementation. (Never encountered them, so limited info.)
  • 3D printer. Also great, especially combined with Kydex for larger areas. My first idea is to make a “standard” Kydex thermoformed enclosure, and a 3d printed “adapter ring” that goes between the Kydex and the deck, and fastens to the rails by whatever means.
  • flexible battery - The P groups themselves can be solid, only the series connections really need to be able to flex. I’d recommend either one of the 3d printed systems (NESE or whatever), and using either wire or flat copper braid for flexible series connections.
  • no BMS - Why?! I don’t recommend going BMS-less unless you have a very, very good reason to do so. It’s just not worth inviting trouble. A good BMS is not that large or expensive. Certainly cheaper than a board-turned-fireball.
  • padding - For insulation, fishpaper is the gold standard - It’s heat and abrasion resistant. For gap filling and vibration dampening, closed cell neoprene foam is my go-to - It’s available in verying thicknesses and widths, and adhesive backed for easy installation. Silicone goop of various flavors is also a favorite, just make sure it’s neutral-cure 100% silicone.
  • fans/intakes are a crutch IMO - They ruin the water/dust/dirt resistance of the final product, and with good careful design can be avoided fairly easy - Especially with an aluminum board to act as a heat sink.
9 Likes
#3

Awesome man! Sure is a lot of questions but you have gone above and beyond, thanks for takin the time to respond :ok_hand: :smile:
I also will have balance leads running from the 18650s to a balance connector similar to that on a Lipo bat and have my hobby charger balance them, after all a bms is only good for built in charging and monitoring of cells, what of which I can take of as I am very kind to my batteries. Or so I thought that’s all a bms did. I’m probably in the wrong and I might add one later down the road :yum:

1 Like
#4

And I love the NESE system idea… could get some metal scraps together or buy some copper or nickel strip… and then join them in series with thick cable to allow flex.
The padding should be good to prevent rattling and abrasion on the esc and battery, and yeah, I don’t know how I forgot that the whole board is essentially a massive heat sink. I your thinking !

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#5

If you are balance charging your pack, then you are correct that a BMS is probably not needed. There are other features of a BMS such as controlling discharge (if you are using a discharge BMS), e-switch to eliminate the need for an anti-spark, easy cell monitoring (with a smart BMS), etc. But if you know what you want, and know what you are doing, then have at it!

Keep in mind that most hobby chargers do not go up to 10S or 12S with a single plug, so you will have two plugs from your pack. Both halves of your pack will have to be charging at the same time, so make sure your charger can do this. Make sure that you wire these two plugs correctly. Make a wiring diagram, post it in the battery builder thread, and get it approved by smarter folks than me.

2 Likes
#6

Yes, I can charge batteries in parallel, done it time and time again with my quad lipos… atleast I thought it works the same with 18650 packs the same ‘size’, (voltage and amperage)
Without the bms I might be missing out on regen and special features, but I’m good for now I think, like I said, maybe eventually :wink:

#7

To my knowledge, you are correct

#8

I’ll have to read up on my wire gauges, but as long as I wire the two separate packs in series with a chunky 10 gauge y series adapter with xt90s, I’ll be fine. I can just recreate the ones I have left over from my rc escs that commonly use 2 or more separate packs… the thing I don’t understand is the guys who run something like a 13s pack… cause that’s a prime, and can’t be devised into segments for charging, so they somehow just merge it with the other pack with a whole extra cell of voltage… without it ‘popping’ when they reconnect the two packs… idk, more homework :grimacing:

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#9

batteries should not pop when you connect them in series

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#10

On a 4 port charger (6s x 4) (only one odd man out to mind when setting parameters)
4s + 4s + 5s
4s + 3s + 3s + 3s

Or use above, split into two charging sets on a 2 port charger

There are 8s chargers
6s + 7s

There are also 13s bms you could wire up to charge externally if space is at a premium.

I still haven’t tackled 13s… yet, but I think about it here and there So much that I should sometime.

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#11

Then why would one need an anti spark plug or switch!?:laughing: They can sometimes spark if the voltages from cell to cell aren’t that’s close and it essentially normalizes voltage across the other cells you just joined in series and sometimes it pops as electricity shoots between the connectors… I was just sayin that if you joined let’s say a 6s and 7s where joined together In series, I’m pretty sure there would be a very loud pop and flash as the 7s drained to over volt the 6s and cause a cell to burst by overcharging it about the safe maximum. you can stick a fork in the nearest outlet to see a spark of your own, but most would advise against that tho :skull_and_crossbones:
The guys running 13s are probably just using a continual pack, probably not a split one, although I could have sworn I had seen that previously on the forum… couldn’t imagine wanting to go that fast oh my goodness… I mean, as a 150Lb guy I can go on 8s around 24-25mph on my board… 13s must just be another world :hot_face:

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#12

Your use of emojis reminds me of things I don’t like to think about cough tiktok… vsco girls… stupid instagram adverts…

Anyway I don’t want to take the piss out of you too much but generally a lot of the people around here know what they are talking about for starters. We know why and when batteries will spark lmao

You could connect a 100v battery in series with a 9v battery and it wouldn’t spark (voltages would add up to 109v, might have issues drawing current but the principle stands). Read up on series and parallel, if you connected those in parallel, the 9v would probably explode. It is imperative that when you connect lipo or liion cells in parallel that the voltages are close, because if they are not, they will normalize as you are alluding to, resulting in a large amp draw from the higher voltage battery to the smaller one, and causing heating of both sides. Not only is this bad for the cells, it can cause worse things to happen if the delta between voltages is too large.

The antispark switch does have a bit to do with the voltage but our particular application doesn’t help it at all either, having a large capacitive load pulling current right away (the caps on ESC’s) makes the spark even bigger than if it were a small capacitive load. The anti-spark helps slow the inrush current so that the spark is non-existant through use of whatever the anti-spark configuration is. Loop keys, mosfet control switches, etc.

13s you start to see some better motor efficiencies, less heating of the motor, slightly less current draw depending on the application. Sure you go faster but that’s just part of it. I would imagine once people experiment outside of the drv8032 and eliminate the erpm problems that people will experiment with the more efficient high voltages

You could go no-bms but in my experience the cheap hobby chargers do a worse job balancing anyway, and it is just way more convenient to plug in a single plug and charge in 2hrs rather than dealing with all the balance plugs.

2 Likes
#13

Connecting packs in series does not give any sparks regardless of the voltage difference.
As long as the circuit is still open there is no current flowing.

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#14

This is what I meant. You are confusing two things into one.

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#15

I was just applying what I knew from the batteries I’ve used in the past, and yes I misunderstood. Idk why u hate the emotes so much as they help people differentiate between you getting mad, joking, or just being excited cause it’s obviously hard to put a connotation on most text and it’s easier than using abbreviations like smh or lmao… PS I don’t have tic tok and barely use social media anyway, I was just trying to be lighthearted… but apparent that bothers u, so no more
Thx for the extra info on the batteries and series connections tho

#16

Then I owe u an apology, I had confused the ‘dangers’ of parallel charging with series connections between batteries, and assumed that by connecting two batteries together their series voltage would naturally try to average the voltage over the new cells added and destroy the much smaller battery.
Good thing to know!

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#17

Lol I don’t care if you use those social media platforms imo they come off as cringey that’s all - probably just because I am older now haha

Np for the information that’s what we are here for

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#18

I had 6S on a 245KV single drive it felt fast at 19mph.

Then I went up to 12S on the same setup and hit 29mph uphill.

#19

yeah, Ive got a 190kv 6384 can motor running 18/40 as a gearing ratio… similar speed on 6s for me to, around 19mph, but on 8s was closer to 23-24mph… so 12s might just be around the 30mph marker

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#20

My batteries were some 30C lipos so that should explain my good hill climbing abilities, helps that I don’t weigh much. Also I was using tiny 70mm wheels

1 Like