Custom Battery Packs? INTERESTED?

@dirkdiggler

I would also lower my gearing to have high torque on higher voltage. Higher voltage would also increase the amount of watt hours which would increase the distance. If I'm not mistaken.

My costs make them the same for someone starting out. Who really wants a 5A lipo charger. I don't :( --> 10A is decent but 5A is slow especially if you are charging 4 or 6 packs for added range.

Life Cycle is another reason to switch over. If the price is slightly the same why bother with lower cycle battery packs if I end up having to repurchase when they get bad.

C rating wouldn't matter much if we're on higher voltage. I wouldn't need to pull as many amps.

That's another issue is certain cells get bad faster than others. Especially, if you don't keep an eye on them. I'd prefer to have a BMS on board to help with that.

The higher voltage would give me the best of both worlds. Higher gearing ratio for more torque + more top speed of about 25-30mph (hopefully, haven't fully calculated).

@voodoojar

Nov 9th sounds awesome..... Let me know the specs. I might just end up buying a few packs from you instead.

@onloop

I'll have to check with vedder again. He mentioned that if the wires within the motor for a 400 or 600kv motor are able to take 10S or 13S voltage. The same motor and same weight with 260kv motor should take the same voltage. Why the companies rate their motors lower? I'm not sure. 6374 motors are able to take up to 12S. I don't think 1S would different much more. Although, that would rate 50mm motors not useable.

I'm willing to risk 2 motors to find out. Unless, someone with more electrical knowledge already knows the answer. Would be helpful.

@dirkdiggler

That's fine if it get's hi-jacked by Bike ESCs. It's also something I'm sure we're also interested in.

I also agree the amount of eBike consumers vs Eboard consumers is more than 10 fold.
 
Random qu but I can't find any charger that chargers batteries over 10s? What charger will you be using for 12s?

voodoojar said:
I've been making some packs with these http://www.amazon.com/Panasonic-NCR18650B-Rechargeable-Battery-Green-quantity/dp/B00CB8PGOE

7s2p 6800mah with bms on/off switch and easy charge with the charger is $160
8s2p 6800mah with bms on/off switch and easy charge with the charger is $190

Using that link a 6s 10ah will cost me $184.50
Right now I'm running with lipos and they costed half the price at $92.

It looks to me that it will cost the same between lipos and the li-ion cells voodoojar posted as li-ion have double the life cycle as lipos. It's like buying the lipos a year in advance.
 
I'm referring to custom built packs that have their own specific usually 2 amp charger. Similar to a laptop charger almost.

That's if you built it yourself. Building anything yourself will usually cost more then the item itself majority of the time. Ex. Try building your own chair? Cheaper if you buy it.

Your costs also don't include the BMS + On/Off Switch + Charger. Of course, voodoo's pack will be much cheaper.

Also if you put the cost of your battery charger as well. These custom packs are much cheaper than cost of a DIY RC Battery setup IMO. These packs are also much safer than standard lipo battery packs.
 
Yes, those are the cells that Tesla is using and they have much better C rating and will last much longer than any Lipo pack...just do a search on that cell and you will see why Tesla give 8 years warranty on that battery!
 
In terms of a battery that is most useful to the broader eboard community I would think that 10S is max. And most suitable.

Because.
1. Not many RC / compact ESC suitable for skate that can support higher.
2. Not many motors, maybe none... that are rated for 13s
3. 13S battery with ability to deliver appropriate power with peak amp draw close to 60a means 13s3p (of high discharge cells = expensive) or 13s4p of cheaper cells... the latter consists of 52 cells. Even with 18650 cells that is a HUGE battery.


My NEW all in one carbon fibre battery & esc enclosure is 10S 18650 & 80A BMS with DUAL 10S ESC built in.

Only 24mm thin... thats less than 1 inch for you Americans. This is not easy, even impossible, to build 10S with lipo whilst achieving high end Wh. Most lipo pouches are about 9mm thick. And if they are 8Ah they are about 170mm long (too wide to go sideways across a deck). So you need to stack two high and run long ways. But then 10S doesn't really work because you have 5 stacks of two.... 8S or 12S is better for building as you get equal number of side-by-side stacks... . But 8S not enough. 12S i think is too much.... too big.... My new battery has built-in BMS so charging is very easy. Never need balancing, one DC plug. Also you can safely charge unattended And the chargers are cheap plug and charge laptop style. Fool proof. This is important when you sell a product...lipo really isn't cheaper either...lipo are a pain to charge & difficult to build housings for... so i believe lipo will not be battery of choice for future of eboards..... .
 
torqueboards said:
I'm referring to custom built packs that have their own specific usually 2 amp charger. Similar to a laptop charger almost.

That's if you built it yourself. Building anything yourself will usually cost more then the item itself majority of the time. Ex. Try building your own chair? Cheaper if you buy it.

Your costs also don't include the BMS + On/Off Switch + Charger. Of course, voodoo's pack will be much cheaper.

Also if you put the cost of your battery charger as well. These custom packs are much cheaper than cost of a DIY RC Battery setup IMO. These packs are also much safer than standard lipo battery packs.

Isn't 2amp slow? I found a charger on hobbypartz http://www.hobbypartz.com/75p-1220-charger.html. 12s charger at 20 amp max for $100 bucks. Looks good

Btw for these battery packs can we also add Ah on our own? As a after market addition?

Regarding a charger I will always want some lipos on hand for times where I'll need extra run Time. Disconnect the ESC from the li-ion battery and connect it to the lipos. So I'll be using a RC charger anyway.

This past Friday I spoke to a tesla guy and he told me that there is 7,000 li-ion cells in the bottom of the car!
 
@onloop - Nice sounds good. 10S is a happy medium and is fun to ride. It's not as much of a stretch as 13S. I think 10S is almost more then enough voltage to have fun as well.

@BShady - 2 Amp is slow but since you don't need to watch it and or care for monitoring it. It's set it and forget it. Lipo chargers you don't want to leave unattended which is why I prefer faster charge rates at least 10amps but that's also bad for the battery packs.

$100 bucks for a charger is expensive. That's not including the power supply. You would need a 500watt+ power supply to power that 12S charger at 20 amps if not 1000watts.

Not adding into the complexity of charging is difficult. Compared to a plug and play charging plug.

I think 10 to 15 miles on a full charge works for about 80-90% of people. Being able to charge or have a spare charger at work/school helps out. Charge for 3-4 hours.

I'm also thinking of offering spare packs that can be easily swapped for an added 10-15 miles for those who truly want it. You just have to disconnect the main discharge wires + charging wires. Trust me, I do like switching packs as well. Carrying a spare 2-4 lb battery in a backpack isn't that bad.

We don't need to stick to RC Lipos :)

7k cells is quite a bit. Funny is Tesla said he plans on producing more batteries than all of China. That's a pretty amazing feat if he can do that.

screen-shot-2014-02-27-at-10-28-10-am.png
 
@torqueboards

10-15 miles is perfect IMO having Addational packs is good as well. But how about upgrading the pack if some wants to add more cells for more runtime and he wants to add it permanently?

Btw I don't think you can include the charger for adding it on the cost. Because you buy it once and that's it. So every year I will replace $200 worth of lipos but my charger is still good no need to replace that. For future years can the BMS be reused (you buy the battery pack and add your old BMS to it) or do every time you buy a pack it comes with a new BMS?
 
BShady said:
@torqueboards

10-15 miles is perfect IMO having Addational packs is good as well. But how about upgrading the pack if some wants to add more cells for more runtime and he wants to add it permanently?

Btw I don't think you can include the charger for adding it on the cost. Because you buy it once and that's it. So every year I will replace $200 worth of lipos but my charger is still good no need to replace that. For future years can the BMS be reused (you buy the battery pack and add your old BMS to it) or do every time you buy a pack it comes with a new BMS?

Yeah, it's doable but adds to much more complication. New enclosure size and new battery pack size.

New people interested in electric skateboards are more interested in the initial cost and a $100-180 charger adds to this cost. Someone who has familiarity with the RC hobby understands but not all people do. Sure, they could buy a cheap $25-30 charger but IMO it's a true disappointment when they realize how slow it is and not only it isn't a true set it and forget it type charger plus the added complexity of learning how to charge can be difficult for some.

$200 worth of lipos to change every year IMO is a waste and unreasonable. Nobody wants an electric skateboard that won't run after a year and would have to spend $200/year to keep it alive. At least, I don't.

The BMS could be used but the percentage of people who would actually swap it would be pretty low. BMS is usually built into the pack and the entire pack is enclosed. Every new pack would come with the BMS. BMS is probably $15-$35 in value.
 
Torque am i wrong in thinking i can just charge all my 18650 li-ion cells in parallel through the balance leads with a regular charger instead of using the bms? But im not sold on that idea and am interested in incorporating a bms. With the bms all you need is a power cord? If i told you how many cells i was going to use could u sell me the bms and tell me how to wire it in? Id like to largely make the pack myself
 
I think at least for us on here, we have different specs we want for our batteries based on size, capacity, and voltage. A pre-made battery pack would be great for selling kits for those who don't want to get involved in the DIY process. I really want to learn more about how to make a pack because I like putting stuff together. But who knows, I might cave and just buy one of your guys' packs if the specs are right.

My main question right now is which cells should we use? I originally thought lifepo4 was the no brainer solution because of life span, even though they're much larger. But it seems we're all leaning towards the 18650's. The weight of each doesn't concern me as much as the size.
 
@Hummina - You can just charge with your regular lipo charger. A few people here already do and do not use a BMS.

You would just have to learn how to do it. You'll need your regular discharge wires + balance wires and then wrap the entire pack if you wanted too and/or have cell holders and you just pop them in and charge separtely. There's a few idfferent ways of going about it.

You could already purchase different BMS setups online and they include a diagram of what areas to solder for the charging leads + discharge leads.

@DrMacGyver - I agree. There are the selected few who will always prefer to make their own packs and that's not a problem at all. I hope this thread simply sparks interest and we can see more build threads on 18650 or 26650 packs in the future.

However, it is always much more expensive when done in batches of 1 than 100. Pre-built will always end up being much cheaper in the long run.

Personally preference. I'm going to research more on LiFePO4. I do like the extended life cycle. I do remember it's much heavier and less voltage in the long run. I'll have to outweigh the cost/benefits.
 
from my comparison of internet ads the 18650 are lighter and probably smaller than even lipo. But thats not including a bms.
If u could sell me the parts torque and add a bit of a guide i think others would probably want the same The hardest part seems to be finding info on what is usable and how to do it simply. You have any interest in selling the parts? imagine youve already figured out whst parts are most suited and work best. I wonder what switch your using for one. And what everything else is for two.
How big is the bms and what are its demensions? If its smallish that sounds like a cheaper simpler route than a charger..which i dont have anyway.
How bout meeting up with me and haggling?
 
@torqueboards

Spending $200 on lipos Is the same as spending $400 on li-ion for 2 years. I just didn't realize that buying li-ion cells in bulk would be cheaper so I would be in to buy with you. I am willin to pay around double the cost of what lipos would cost me.
I also like @hummina idea of just selling the parts and we will put It togather ourselves. Creates a good learning factor.

I forgot who or the case exactly was but someone made a switch that he can run his batteries as 6s 10ah or 12s 5ah. Do you think we can make that possible?

Regarding the encloser can't you make it in 2 parts and make a way to attach the parts to gather?
 
"I forgot who or the case exactly was but someone made a switch that he can run his batteries as 6s 10ah or 12s 5ah. Do you think we can make that possible? "

On a side note..why would this be of use other than to go faster? If the watthours will be the same couldnt you just ease off the throttle for more range and stay at 12s
 
@ Hummina

For the most part pretty much all the parts are all readily available on the internet. There would be no point in selling parts when you can get them already at pretty decent prices.

I don't have anything at the moment. I wouldn't be inclined to sell parts through myself as it always equals out to be more since it requires more customer service. LOL :) In the end it's not worth it.

However, for the true "DIYers and Makers" it's already out there. Just not everyone has fully switched over. Lipo's are the easiest solution which is what we currently go for. Since most of us already have our boards setup. Creating your own custom pack to your own specs is a new project :)

@ BShady

Personally, I would also factor in the cost of an on/off switch $50, battery led indicator and even a charger, etc. Also other costs that don't have an associated dollar value safer chemistry, safer charging, one plug charging. All those alone IMO would trumpt the cost savings of lipo. A lipo could die sooner than a year if you don't watch it precisely. Also IMO harder if you have 4 or 5 packs. I necessarily don't really want to watch my pack at all period besides lumps in my pack.

As for 6S or 12S. I would just run it as one. I don't think it would save a whole lot but then again I'm not an EE. Maybe someone with more insight could contribute.

BTW - I'm also purchasing packs pre-built and not planning on purchasing by single cell.

Anyhow, I do like how you guys are definitely interested in swapping to lithium ion and BMS, charging solution. :) That's mainly my goal. Would be great to see more custom lithium ion packs out and about. We've seen this forum grow tremendously within the last year or so and much more people have boards. I think this would be a good next project. As for me.. I have a bit too much on my plate to actually make my own packs for fun. :cry: I'm still waiting on making an eBike!

I'm sure everyone on here are alike.. I truly wish I had 50-100 hours per day. I for one wouldn't be bored.
 
Once we all feel comfortable with the knowledge of building the packs, we can do a group buy. I would also feel comfortable spending twice the price of lipos. I'm not sure if we're considering using these, but I saw that A123's needed to be spot welded in the assembly. Is soldering an equal substitution for that? I've only watched how-to videos for lifepo4 headway cells, but not for 18650's. Any how-to information on those?

Regarding charger, will I need a new one? Also my HK150a esc is also only rated for 6s, so I hope the cost of this project won't exceed the batteries alone. This is what I've got now: https://www.hobbyking.com/hobbyking/store/__6478__IMAX_B6_AC_Charger_Discharger_1_6_Cells_GENUINE_.html

And regarding 12s packs, I feel like those high voltages are primarily for MTboards. I could be wrong, but I don't think we need to consider anything beyond 10s. If you'll be converting to pneumatics like me, then consider the gained speed from those. Capacity should be the main focus, which imo should be 10ah. Especially since pneumatics will eat up more range. My 6s lipo is 5000mah and I've realized it's way too small. I only get about 6ish miles, which is annoying.
 
what about doing a 8S1P 10000mAh by adding these two :

http://www.hobbyking.com/hobbyking/store/__65272__Multistar_High_Capacity_4S_10000mAh_Multi_Rotor_Lipo_Pack_EU_Warehouse_.html

They seem compact and 20C .. will give like 200A maximum. I got an alien twin power 4.4 setup ... 270kv ... 150A ESC... These lipos seems to make the deal !

or for something less higher 4x 2S 5000mAh - will give 8S 10000mAh in 20C
 
As for BMS depends on what type of pack your creating. You could use the following - http://www.batterysupports.com/36v-37v-42v-10s-60a-10x-36v-lithium-ion-lipolymer-battery-bms-p-267.html

If you see the diagram here it shows you how to connect the balance plugs which plug into the BMS.
10Sclogo.jpg~original


You can setup the charging port for a typical barrel jack and/or the common 3 prong connectors. Barrel jack might be limited to a certain amount of amperage.

http://www.buya123batteries.com/ is mentioned a lot here on ES and have authentic cells. They are expensive but what you can also do is purchase HP Laptop battery packs (there is a specific kind that has 18650 cells). This route is definitely much cheaper and probably what most people should do if you plan on it.

They also have alloy shell chargers here as well - http://www.bmsbattery.com/alloy-shell/26-alloy-shell-400w-lifepo4li-ionlead-acid-battery-ebike-charger.html.

I'm sure there are other places as well in which you can buy from. This is a broad aspect of the entire picture. Please make sure to do additional research and verify your plan before completion as I am not responsible. This isn't a step by step guide :mrgreen:
 
I just started watching this how-to series, but it seems pretty comprehensive. I think it's just missing the bms info, but I think that could be coupled with these videos pretty seamlessly to reach our final product. This all seems simple enough, just need to have the time to do it.

[youtube]v6kc4ALFuG4[/youtube]

And an instructables: http://www.instructables.com/id/Make-an-inexpensive-Lithium-Ion-Battery-Pack/?ALLSTEPS
 
U cant use typicsl laptop cells. They wont discharge enough amps. There are a couple companies selling high discharge li-ion cells. High c rating or amp current is what you need and u can add to the amps produced at one time by adding to the size of the total pack. A 10ah pack will give more than a 5ah. I forget the formula but thats the gist of it. I forget how many amps people get to on a skateboard and wish i knew. If the batteries cant supply the power..you wont get the power and will also be damaging your batteries

Im confused...do you still need a charger if you have a bms w li-ion? If not i dont see much point in having it- theyre a pretty safe chemisty and as long as they can be charged in series i dont see the point in having the bms

Torque the bms u linked does 10s. But how about if it takes something like 24 cells to make the pack have a decent ah..can each cell still be monitored? It also says 60amps max..do you find thats enough?
 
If I'm understanding this correctly, having the bms built in means that all you do to charge is plug in your pos/neg wires to the charger. Without a bms means you need to plug in the balance cable AND the pos/neg wires.
 
drmacgyver said:
If I'm understanding this correctly, having the bms built in means that all you do to charge is plug in your pos/neg wires to the charger. Without a bms means you need to plug in the balance cable AND the pos/neg wires.

Aha. That's what I'm finding. Is charging solely through the balance wires slow and how would u do it if making a pack would include about 24 batteries and more Balance leads than the charger recognizes for one pack?
 
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