Custom Battery Packs? INTERESTED?

No, I can agree that it's probably a more ultimate spec (higher voltage). Will a 6s 18650 pack be a wet noodle compared to a lipo, or would it perform the same? It's just costly for us who are limited with 6s setups. It's frustrating, trust me, but I like to think there's enough of us with them who would use a 6s 18650. Can anyone chime in? Bueller... Bueller...
 
I still don't get this thread, but I'm not trying to stop you.

I've seen many ebikers go to or back to Lipo due to issues with other chemistries. Lipo isn't perfect, but so aren't the others. I've tried Li-ion on a board and the climbing ability of the board sucked because of battery sag, not a high enough C rating. One of the reasons many high powered ebikes use Lipo, and they are only looking for 30a discharge. I agree that a commercial product should be much more user friendly, but RC gets away with using them. You put down a lot of money for a Traxxas RC car and the user is expected to learn how to handle Lipo. Altered skateboards mentioned the problems with using Lipo in their product and even he said on his own personal board he was using Lipo, not Li-ion like they sell. Again, I think that as soon as RC starts using a different chemistry, I'm game, but they use Lipo because the cost/weight/size ratio is the best current option.

Tons of good articles on the web about battery chemistry, here's one from an ebike site:
https://www.electricbike.com/high-current-batteries-not-lipo/
High performance requires high amps, but LiPo batteries can be dangerous for someone who is inexperienced with them. LiPo is capable of putting out VERY high current (the C-rate), and if you are building a racing E-bike, they are simply the best choice.
A LiPo pack will be smaller, lighter, and will put out more peak and continuous amps than any other pack you can buy. The problem is that…for E-bikers who want something that is much safer, but has better performance than the average common battery pack, the options are not well known.

I see it mentioned that these packs will be about the same price as Lipo packs, but what are some actual figures. I know that a decent 18650 cell pack for a bike is well over $500. Even a 10ah 36v pack sells for around $400. Shipping on those is also pricey. Which is what you are planning on making, correct? If you can get packs for cheaper than that I imagine the ebike community would jump on those. Charge rates on these are also usually only 2.5amps, another reason why RC likes lipo. I don't see how a $35 charger and two/four 4s or 5s 5000mah packs at $50/$100 are about the same price as what you are suggesting. I can charge 4 5000mah packs on my cheap charger with a balance board for an extra $10 and they'll charge in less time than a 10ah Li-ion pack.

If you want ease of use for a 10s Lipo pack, just use the cheap balance chargers on two 5s packs. You can buy those for like $10 and are basically foolproof. That's what came with one of my first RC cars. Didn't someone permanently attach a balance charger to their board?

Anyway, carry on. Check out the ebike section of this forum, there is more user experience over there about batteries.
 
@drmacgyver - 6S should be fine. I"ll have a 6S setup. It's pretty much the same either way.

@dirkdiggler - I understand what your saying. I agree as well. However, with that said. Many eboard companies are doing just fine without lipos. Granted if you do want to pull more amperage. You definitely shouldn't use a BMS and RC lipos are meant for that reason.

We'll definitely test it and try it out. Just checking with others and checking to see if there are better options.

I think we all have a slight misunderstanding on our actual continuous amp usage and peak amp usage.

As for that onloop - I feel you on wanting 60A cont amp usage but after thinking about it for a while and doing more and more research. It's not ideal. We aren't looking at 60A cont but only 20-30A cont and 60-80A peak.

I should have some packs soon that I will be testing and will let everyone know what I find and how they run. Just purchased an amp logger as well.
 
Thank you much Torque! Looking forward to your findings.

If I'm not mistaken, Boosted and other produced eboards don't use lipos. I'd imagine they use something much safer for the average consumer to just plug and play. I think this is why we're so eager to find a different battery. We want to get as close to what they're making without having to buy their product. If the cost of li-ion is over time the same as lipos, but are safer than lipos, then I think that answers that. Add to that the fact that li-ion packs can be customized in both power, capacity, and shape. Based on these points alone I think we can all agree that li-ion wins hands down. Cost is a big factor, but it seems fair to pay more for safer batteries, longer life span, and a more compact board. Right now I'm on a tight budget and I need to upgrade to pneumatics, so luckily I can be patient for li-ion.

But like you mentioned Dirk, performance is another story. I don't know much about the chemical or electronic aspects of the hobby, so I have to base my knowledge off what others have done until I can experiment and create my own observations. Li-ion obviously works because that's almost all I see talked about on the e-bike section. Aside from the couple eboarders who have implemented their own li-ion systems and can attest to their success, the rest of us are just theorizing that li-ion can be a substitution. I guess it goes back to my first point about Boosted, Marbel, etc. They're doing it, so why can't we? Ultimately we'll just have to test and observe.

Regarding RC's, the power:size ratio is much better with lipos like you said, so it's obvious why they use lipos in their hobby. But we have the luxury of having (probably on average) 120 square inches of space to spread our batteries out, allowing us to make some pretty sleek boards. So I'd imagine that's one reason RC's won't make the switch anytime soon. Again, performance is another story, which we'll just have to wait and see.

I have to admit I'm on the fence about whether li-ion will perform as well as lipos after reading differing opinions. I'm just anxious to see the results.
 
@torque.
I am building this pack with higher discharge capacity then required. I am over engineering the pack to ensure longevity and superior performance.... i don't want the cells to be stressed. So yes they can deliver 60a. But will only be asked to deliver 15-30A continuous. However it can Peak at 60 for a few seconds if needed. Current Limited with current limiter on ESC.


Price for battery, BMS & charger is about $390. Price Inc free express shipping anywhere in the world
 
@dirkdiggler did you use li-ion on your MTB? Explain what you found, what voltage you where useing, and what amps you were pulling and what the difference was between lipos under the same circumstances.

I think I read that on average a e-boarder pulls 20amps maybe 40amps peak. E-MTB can pull up to 80amps! I also heard that higher voltage can lower your amps. If we run higher voltage li-ion packs, then we cant pull the same amps, but we can lower it to the amount that the cells can produce. It's possibility that even after we make a higher voltage li-ion pack, the amp draw will still be to big, but we have to try.

Cost wise: if it will cost more than 2.5 times the amount to make a li-ion pack then a lipo pack then I'm out. The main factor that sold me was the easy of li-ion. But that was if all the specs are the at least the same including the price.

Stolen quote!! 1 test is equal to 1,000 opinions!
 
BShady said:

Interesting. The numbers don't say as much as the specific replies do. Still, as much as people seem to be using lipos, I'm drawn towards 18650's for the points mentioned. I like that they don't require as much attention as lipos.

Also, I've seen several times the recommendation to add a fuse to the packs. Is this something you all have considered into your packs? I'm not sure how/where to add it, but it seems like a good idea. Better safe than sorry.
 
drmacgyver said:
Interesting. The numbers don't say as much as the specific replies do. Still, as much as people seem to be using lipos, I'm drawn towards 18650's for the points mentioned. I like that they don't require as much attention as lipos.

Also, I've seen several times the recommendation to add a fuse to the packs. Is this something you all have considered into your packs? I'm not sure how/where to add it, but it seems like a good idea. Better safe than sorry.

I also can't maximize space with lipo packs from HK. Good suggestions. I do know that most of the other packs do include a fuse.
 
We use those 120amp fuse for an on/off switch.

LQvGf2Z.png


These fuse's you can usually get for a pack.
 
Im over the 18650s.
Lipos are lighter and smaller for the power and really cheap
With the single lipo poptart pouch being 8mm its pretty space maximizing
The vulnrability of their softness isnt a big issue since theyre in a case
Theyre much easier to get going as you just have to get connectors right as apposed to building a pack which looks to be another difficult soldering job.
Could be fun though and salvaging batteries would make many eco-tech-cheapo points

Why dont people use bms with lipo though?? If safety is the issue theyre the ones that need it more, or maybe their softness is a boon as apposed to an exploding double A can

Why cant we just get a 22 volt 5 amp wall plug that also flips the ac to dc and charge batteries through simply a bms?

That switch is a monster and i never could find a smaller one I bought it and returned it and am waiting for someone to show a schematic for a DIY one that's smaller. Since the x90 connectors incorporate an anti-spark there must be a simple swith that could be made. Dare i say.print it and add wires n capacitor
 
Yeah, don't get me wrong. Lipos are great. I'm looking for an easier solution though.

I'm all for it :) Can't wait to get rid of my lipos to be honest. I don't want to swap packs as often. I want a one plug solution for my batteries (easier to charge at work). Don't need to bring my Lipo charger or connect 4 batteries and press buttons on a display screen. Plug it in and forget about it.

IMO Using a BMS with a lipo is a bit unpractical as the benefit of a lipo is the high discharge rates with a BMS there that isn't as much of an option.

Looking at a 6S5P 11ah pack. $250 including charger w/o shipping. Charger, On/Off Switch, Fuse, Battery LED Indicator. Maybe + USB Port :mrgreen:

6S 10ah lipo pack. $22/each 3S 5000mah 20C Zippy Flightmax. 4x $22 = $88 + $35 for 4a power supply/charger = $123 + $50 on/off switch. $173 TOTAL w/o shipping.
 
torqueboards said:
Looking at a 6S5P 11ah pack. $250 including charger w/o shipping. Charger, On/Off Switch, Fuse, Battery LED Indicator. Maybe + USB Port :mrgreen:

6S 10ah lipo pack. $22/each 3S 5000mah 20C Zippy Flightmax. 4x $22 = $88 + $35 for 4a power supply/charger = $123 + $50 on/off switch. $173 TOTAL w/o shipping.

@torquboards If that's how much you can make a pack or either I'll buy one from you or just send me the links and I'll buy the parts. $250 is very good!

Why can't we make a higher amp BMS? It's got to be possible.
 
6s5p 11ah is 50a cont about 120a peak 2 seconds. 10a cont per cell. Although, voltage is lower. This type of pack would be for everyone on 6s setups or using 6s car escs.

We could go 6s6p 13.2ah and get 60a cont. 60a cont is like 60a continuously for 10 seconds+ but it never gets to that point. We get to 60a 80a but for maybe 3-5 secs or so.

I might get a USB port also with the BMS and you can mount it to your enclosure. The USB port will put out 5v from the pack WOOT! :mrgreen: Not sure how much that will add in cost though just yet.
 
$250 sounds very fair for those specs. I already have the IMAX B6 with built in power source, so would I need another charger? If not how much would that lower the price? Also curious to see the parts, as I'd really like to learn and build one. I think a big determining factor might be if those packs are spot welded and made from new cells, not recycled ones. Also if I actually can find time to make it. Whether I buy or build one though, this is going to be a 2015 upgrade. This year is pneumatics :D
 
drmacgyver said:
$250 sounds very fair for those specs. I already have the IMAX B6 with built in power source, so would I need another charger? If not how much would that lower the price? Also curious to see the parts, as I'd really like to learn and build one. I think a big determining factor might be if those packs are spot welded and made from new cells, not recycled ones. Also if I actually can find time to make it. Whether I buy or build one though, this is going to be a 2015 upgrade. This year is pneumatics :D

I would just use the built in charger. I wouldn't bother messing with the IMAX B6. However, you could make it work but you would have to customize it. The balance wires are all soldered onto the BMS so their is no additional JST port for the balance connectors. The charger doesn't lower the price much. Not sure why you would want to save maybe $20-$30 to have to watch/monitor and plug in multiple wires. These chargers are green and red LED lights. Very simple.

They are all new cells. We'll see once I get closer to it.
 
Ahh, ok I get it. Still learning about how all the pieces in the system are connected and work. I think buying one of these packs would be a better starting point seeing how much complexity goes into it. Then after I can build my own once I have something physical to learn from.
 
The simplicity sounds nicer for sure.

Are you saying that the lipo higher discharge rate requires a more robust/expensive bms or is there more to it? If the bms could go with lipo cells as low c as the 18650 the chemistries are almost the same and I dont see why it wouldnt work

Can you show some pics of what all parts of the set-up looks like and how it opporates? Id like to see how big the charger is and know how long it would take. Is the charger on-board too.

I still dont understand why a charger is necessary. If the batteries had a bms and the supplied power were to be appropriately something like 22v and 2amps. With a bms monitoring the charge rates and max charge the charger seems redundant.
 
@torquboards if your going with higher discharge wouldn't that run into the same problem as putting a BMS on lipos?

@hummin the BMS Is the charger, it just needs a power supply/source.
 
Ok bshaddy thanks..but are you sure. It seems from what torque is saying there are two

How about induction charging and im in

http://www.gizmag.com/bmw-induction-charging/32863/
 
Hummina Shadeeba said:
How about induction charging and im in

http://www.gizmag.com/bmw-induction-charging/32863/

South Korea started doing it with their public buses. Always frustrates me to see other countries advancing, while we're still dragging our feet...
http://www.wired.com/2013/08/induction-charged-buses/
 
I found the web page ive been looking for days. Electricity is here to stay.

http://peswiki.com/index.php/Congress:Top_100_Technologies_--_RD


Sorry torque...back to our regular program
 
@Hummina

You can use BMS on Lipos. You could have higher discharge rates also. There are some that are 80A and 100A I believe. They just cost more and/or are bigger in size.

If the cost isn't far off. Safer chemistry would be better. I still don't understand the need or want to keep lipo. The discharge rates are severly overdone I think. I've wanted the higher discharge forever but realize it's a bit overdone as we never reach those amps.

37v * 50 amps = 1850 watts -- Unless your strapped to the board 1850 watts would put anyone on the floor. We also aren't running 1850 watts for 2 or 5 minutes straight. It's only for a few seconds do we use that much and we're back to 200-300 watts on average.

A one plug charger is just like a laptop charger. No thinking to it. It operates similarly to a laptop.

You still need a power supply from the wall to your BMS. BMS is only a management system it doesn't charge itself and doesn't give off power only monitors power going through it.

You also get a ton more cycles. There's a reason no production boards are using lipo.
 
Back
Top