Resend my activation email : Register : Log in 
BCF: Bike Chat Forums


Project Electric (Push) Bike - Now With Video

Reply to topic
Bike Chat Forums Index -> Show & Tell Goto page Previous  1, 2, 3, 4, 5, 6, 7, 8, 9  Next
View previous topic : View next topic  
Author Message

The Artist
Super Spammer



Joined: 06 Jan 2008
Karma :

PostPosted: 18:07 - 12 Oct 2014    Post subject: Reply with quote

Is this going to be used regularly? What about all those link bars corroding in the British weather?
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Aff
World Chat Champion



Joined: 05 May 2011
Karma :

PostPosted: 18:58 - 12 Oct 2014    Post subject: Reply with quote

The Artist wrote:
Is this going to be used regularly? What about all those link bars corroding in the British weather?


Most likely not.

But even if it was, the battery shouldn't be getting cold or damp/wet as it would wreck the cells. The strip wouldn't be an issue as it's 99.9% pure Nickel.
____________________
Current Bikes:Honda 929RR Fireblade, Honda CD200 Benly (Project), Stomp Z2 140
Electric Bike Project
 Back to top
View user's profile Send private message You must be logged in to rate posts

Smudger
L Plate Warrior



Joined: 26 Oct 2014
Karma :

PostPosted: 17:04 - 26 Oct 2014    Post subject: Reply with quote

First...Hi...new member, joined to check out info on Bandits, came across this posting, a great project and read.

Have also built a leccy bike also, using a Commencal Supreme DH bike,decent spec, full suspension, Hayes Hydraulic brakes and oversize rotors, a Crystalyte HS3540 & 45amp controller conversion.

I am using 40- 5000mah Lithium Polymer cells 20 in series then paralleled giving me 84v off charge at 10amp rating.

Bike is quick, to say the least......


https://www.youtube.com/watch?v=22n-V_M5KYk&index=1&list=UUCHzwaRdllXPskLGm9SBbFw

A short vid...run to the pub on 'ThunderBike'

All the best.
Tony
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

The Artist
Super Spammer



Joined: 06 Jan 2008
Karma :

PostPosted: 23:45 - 10 Dec 2014    Post subject: Reply with quote

If I was to build something like this, is the only different between using lead-acid and lipo batteries the weight?

I mean I can get 4x 12v 7Ah SLA batteries for £70 and would weigh in at under 10kg's.
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

G
The Voice of Reason



Joined: 02 Feb 2002
Karma :

PostPosted: 00:22 - 11 Dec 2014    Post subject: Reply with quote

You can use up a higher percentage of a lithium battery's ah each use and it will last for longer compared to a similar capacity lead acid.
Lithium will also typically have from quite a lot to a massive lot higher amp rating (instantaneous power, though rarely an issue for a lower powered push bike.)
As an idea, a single half kg lithium battery I can easily hold in my hand will jump start my 2.2td van when the lead acid battery won't even turn it over.

Lithium batteries can typically be safely charged from a lot to massively faster.

For prices, you can get a 5ah 18v lithium battery for £25 or so.
So that's 90WH for £25 = 27p/WH.
For your 4 batteries we have 336WH for £70 which gives us 14p/WH.

HOWEVER, typically you'll discharge lead acid to 50% and lithium to 80%, say. 31p/WH for lithium vs 42p/WH for lead acid.
 Back to top
View user's profile Send private message You must be logged in to rate posts

The Artist
Super Spammer



Joined: 06 Jan 2008
Karma :

PostPosted: 00:32 - 11 Dec 2014    Post subject: Reply with quote

G wrote:
You can use up a higher percentage of a lithium battery's ah each use and it will last for longer compared to a similar capacity lead acid.
Lithium will also typically have from quite a lot to a massive lot higher amp rating (instantaneous power, though rarely an issue for a lower powered push bike.)
As an idea, a single half kg lithium battery I can easily hold in my hand will jump start my 2.2td van when the lead acid battery won't even turn it over.

Lithium batteries can typically be safely charged from a lot to massively faster.

For prices, you can get a 5ah 18v lithium battery for £25 or so.
So that's 90WH for £25 = 27p/WH.
For your 4 batteries we have 336WH for £70 which gives us 14p/WH.

HOWEVER, typically you'll discharge lead acid to 50% and lithium to 80%, say. 31p/WH for lithium vs 42p/WH for lead acid.


I just found this.

https://sites.google.com/site/shelbyelectro/batteries/lead-acid-batteries-do-not-belong-on-an-ebike

Seems to agree with everything you say. The price is LiFePO4 battery packs is mad though. It would be cool to make one like in this thread but lots of work!
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

G
The Voice of Reason



Joined: 02 Feb 2002
Karma :

PostPosted: 00:57 - 11 Dec 2014    Post subject: Reply with quote

My costs are for lithium polymer (zippy 5000mah, 5s from Hobbyking). Lifepo4 will have a good bit longer life and probably will do even better when you are considering total watt hours over life of the battey, as opposed to one cycle.

However, I'd not bother with them until you're sure the investment is worth it - as with other investments, you also have to be sure it's worth spending the money now, as opposed to a lower investment (on lithium ion/polymer) in the short term - there's general monetary, that you'll hopefully be earning more money in the future etc, that the the technology will hopefully improve and the risk they could be damaged or stolen etc.
 Back to top
View user's profile Send private message You must be logged in to rate posts

Sload
World Chat Champion



Joined: 28 Aug 2011
Karma :

PostPosted: 01:00 - 11 Dec 2014    Post subject: Reply with quote

Just read all of that and must admit you lost me a bit with your batteries and your makeshift spot welder Laughing , seriously impressed and you're completely nuts Thumbs Up
____________________
Honda Varadero >> Triumph Speed Four >> Honda CBR1100xx
 Back to top
View user's profile Send private message You must be logged in to rate posts

The Artist
Super Spammer



Joined: 06 Jan 2008
Karma :

PostPosted: 01:03 - 11 Dec 2014    Post subject: Reply with quote

If I was to make a 48V battery pack from 18650's (12 packs in series, each pack being 8 18650's in parallel), what charger would you recommend? Ideally I want to be able to charge them up in a couple of hours. I have mains and a DC power supply upto 5A @ 30V.
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Aff
World Chat Champion



Joined: 05 May 2011
Karma :

PostPosted: 11:28 - 11 Dec 2014    Post subject: Reply with quote

The Artist wrote:
If I was to make a 48V battery pack from 18650's (12 packs in series, each pack being 8 18650's in parallel), what charger would you recommend? Ideally I want to be able to charge them up in a couple of hours. I have mains and a DC power supply upto 5A @ 30V.


That pack would likely be about 850Wh, so to charge in about 2 hours you would need to charge at at least 500W.

My charger at the moment is powered by a 24V 40A supply, but is limited to 6s.

A popular way to bulk charge (no balancing) is to hook up some cheap meanwell power supplies in series. They have a pot on to adjust the output and are a CV supply. So you can set it to the hot voltage and it will charge the battery to that. You could then balance with an external balancer.

Or do what I do and charge them in 6s segments.
____________________
Current Bikes:Honda 929RR Fireblade, Honda CD200 Benly (Project), Stomp Z2 140
Electric Bike Project
 Back to top
View user's profile Send private message You must be logged in to rate posts

The Artist
Super Spammer



Joined: 06 Jan 2008
Karma :

PostPosted: 13:48 - 11 Dec 2014    Post subject: Reply with quote

Aff wrote:
That pack would likely be about 850Wh, so to charge in about 2 hours you would need to charge at at least 500W.

My charger at the moment is powered by a 24V 40A supply, but is limited to 6s.

A popular way to bulk charge (no balancing) is to hook up some cheap meanwell power supplies in series. They have a pot on to adjust the output and are a CV supply. So you can set it to the hot voltage and it will charge the battery to that. You could then balance with an external balancer.

Or do what I do and charge them in 6s segments.


6s being 6 cells? It would be awesome if you could post some more pictures of your setup.

Any particular charger you could recommend? Any other tips as I am genuinely considering this as a commute option at the moment.
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

G
The Voice of Reason



Joined: 02 Feb 2002
Karma :

PostPosted: 14:34 - 11 Dec 2014    Post subject: Reply with quote

Yep, S means 'serial', so what you describe would be written as '12S8P' - 12 lots of 8 parallel cells connected in serial.

They're not cheap, but there's various balance chargers that will do 12s with 1000w or more total output, if you're fine to separate into two lots of 6S you get a few more options.
 Back to top
View user's profile Send private message You must be logged in to rate posts

Aff
World Chat Champion



Joined: 05 May 2011
Karma :

PostPosted: 17:06 - 11 Dec 2014    Post subject: Reply with quote

The Artist wrote:

6s being 6 cells? It would be awesome if you could post some more pictures of your setup.

Any particular charger you could recommend? Any other tips as I am genuinely considering this as a commute option at the moment.


My set up is pretty much fully documented in this thread.

If I was looking at making a commuter, I probably wouldn't make a 12s pack.

I would first decide on what motor I wanted, then based on its Kv rating, I would decided on what voltage pack to use to get about a 15-20mph cruising speed.

Then put as much capacity as I could in the bike at that voltage so that I could charge as little as possible.
____________________
Current Bikes:Honda 929RR Fireblade, Honda CD200 Benly (Project), Stomp Z2 140
Electric Bike Project
 Back to top
View user's profile Send private message You must be logged in to rate posts

The Artist
Super Spammer



Joined: 06 Jan 2008
Karma :

PostPosted: 19:50 - 11 Dec 2014    Post subject: Reply with quote

Aff wrote:
The Artist wrote:

6s being 6 cells? It would be awesome if you could post some more pictures of your setup.

Any particular charger you could recommend? Any other tips as I am genuinely considering this as a commute option at the moment.


My set up is pretty much fully documented in this thread.

If I was looking at making a commuter, I probably wouldn't make a 12s pack.

I would first decide on what motor I wanted, then based on its Kv rating, I would decided on what voltage pack to use to get about a 15-20mph cruising speed.

Then put as much capacity as I could in the bike at that voltage so that I could charge as little as possible.


I am a large fellow and my bike is heavy as well so I was looking at the 1KW 48v in hub front wheel drive motors you can get everywhere for £200 including a controller and bits and pieces.

I am struggling to sort out a charging system. As much as I would like to use one of those Powerlab's, they are very expensive. I might be being retarded or the wording is confusing to a non-electrical person but could I use 2x iMAX B6 chargers? One for each 24v pack? 50W, 25V = 2A so to charge 48 cells of ~2.5Ah would take 60 hours if they were totally dead and charging was linear.

The only real motor options are 36V which is a weird voltage or 48V which can easily be done as 12S with 18650's.

Any recommendations?
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Aff
World Chat Champion



Joined: 05 May 2011
Karma :

PostPosted: 20:08 - 11 Dec 2014    Post subject: Reply with quote

Dont pay much attention to the voltage of the motors, it's just how the Chinese market stuff.

You can run pretty much any motor at any voltage.

The higher wattage ones will just have more copper in them and better heat dissipation.

I have seen the motor I use being sold as a 36V 350W motor, but I have been running it consistently at 3kW and it's fine.

The motor will have a Kv rating which is probably most importantthing you need to know. This will be a value around about 10 and tells you how many RPM the motor will do per Volt. So you can buy a motor around the speed you want to do.

This is important because these direct drive hub motors have a very weird efficiency curve. They usually look something like this:

https://www.johnsonelectric.com/common/en/images/resources-for-engineers/automotive-applications/motion-technology/ec-motor-brushless/performance-curve-01.jpg

So you have a small area around 70-80% of the motor rated speed where it is very efficient, with sharp falls in efficiency around it.

This is why things like pedalling when pulling off and going up hills makes so much difference to your range.

For commuting I would be aiming to make a bike that stays in that range as much as possible.

As for a charger, don't bother with iMax B6's they spac out when trying to charge large batteries.

I would spend the £100 on a decent balance charger.

But you can do it cheaper and faster with meanwells if you dont balance.

Or you could try one of the dodgy Chinese eBike chargers.

Another option would be to add a BMS to you pack. Then all you need to do is give it power and it will sort it for you. I don't trust these though. I have seen them kill packs and bikes.
____________________
Current Bikes:Honda 929RR Fireblade, Honda CD200 Benly (Project), Stomp Z2 140
Electric Bike Project
 Back to top
View user's profile Send private message You must be logged in to rate posts

The Artist
Super Spammer



Joined: 06 Jan 2008
Karma :

PostPosted: 01:20 - 12 Dec 2014    Post subject: Reply with quote

I think this would do.

https://www.ebay.co.uk/itm/SKYRC-RS16-180W-16A-Balance-Charger-Discharger-SK-100078-01-/331368718953?pt=UK_ToysGames_RadioControlled_JN&hash=item4d271d6269

If my maths are correct, 180W means I should get 7.1 amps @ 25.2V = 33 hours to charge 96x2500mah cells, 2x 6S8P.
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

The Artist
Super Spammer



Joined: 06 Jan 2008
Karma :

PostPosted: 20:20 - 16 Dec 2014    Post subject: Reply with quote

Hub motor ordered. Very Happy

I am going to make my own battery pack but this will take time and I want to do that properly and so rather than rush that, I am going to go for a cheap lead acid solution for the time being. After doing much research, I am basically copying what everyone else has done. There are quite a few e-bike homemade jobbies out there doing the same things, even down to the spot welding and magnets for charging and they all seem to work.

For now though...

https://www.batterymasters.co.uk/ProductDocs/SLAUMXNP12-12-TECH.pdf

4 of those in series = 15kg's, realistically looking at maybe 7-8Ah but that should be enough for my commute of ~4 miles each way. I hope they don't mind having 20A pulled through them momentarily although I am thinking of limiting the current to 10A max just so I don't completely ruin my range. So I can get those + a cheap charger for <£100.

OR do I spend £180 on a chinese lithium 48v 12ah pack with BMS?

Which option would be best for short term?
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

G
The Voice of Reason



Joined: 02 Feb 2002
Karma :

PostPosted: 20:39 - 16 Dec 2014    Post subject: Reply with quote

I'd definitely be having a look at hobby king etc personally.

Might cost you a little more, but should last a good bit longer and generally offer better performance, as well as meaning you don't get a lead acid charger which you can't use with lithium.

Remember to factor in being able to use more of the capacity of lithium batteries.


Last edited by G on 20:45 - 16 Dec 2014; edited 1 time in total
 Back to top
View user's profile Send private message You must be logged in to rate posts

Aff
World Chat Champion



Joined: 05 May 2011
Karma :

PostPosted: 20:40 - 16 Dec 2014    Post subject: Reply with quote

Rather than wasting your money on lead that would never be used again, I would buy 4 of these:

https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9176

More usable capacity, only weighs for 4kg, can be used for other things after and an output way exceeding your needs.

:edit: the fact that they are already connectorised into 6S bundles also makes charging very easy and affordable.

You can just rearrange the order you connect them and and charge as a 20Ah 6s pack.
____________________
Current Bikes:Honda 929RR Fireblade, Honda CD200 Benly (Project), Stomp Z2 140
Electric Bike Project
 Back to top
View user's profile Send private message You must be logged in to rate posts

The Artist
Super Spammer



Joined: 06 Jan 2008
Karma :

PostPosted: 21:18 - 16 Dec 2014    Post subject: Reply with quote

Aff wrote:
Rather than wasting your money on lead that would never be used again, I would buy 4 of these:

https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9176

More usable capacity, only weighs for 4kg, can be used for other things after and an output way exceeding your needs.

:edit: the fact that they are already connectorised into 6S bundles also makes charging very easy and affordable.

You can just rearrange the order you connect them and and charge as a 20Ah 6s pack.


Ahh, bargain! There is so little information available on all the different sorts of batteries out there. Thanks for your help.

It say 4mm bullet connectors so if I get a pack of these
https://www.hobbyking.com/hobbyking/store/__34477__HXT_4mm_Gold_Connector_w_Pre_installed_Bullets_10pcs_set_UK_Warehouse_.html
I can just wire in some spade connectors which I have plenty of and configure them easily for use/charging.

One last thing, chargers, I have a spare 430W PSU from a PC so I was thinking of buying this charger.
https://www.hobbyking.com/hobbyking/store/__56454__Turnigy_4x6S_Lithium_Polymer_Battery_Pack_Charger_UK_Warehouse_.html
Means I should be able to charge all 4 packs separately all nicely balanced.
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Aff
World Chat Champion



Joined: 05 May 2011
Karma :

PostPosted: 21:35 - 16 Dec 2014    Post subject: Reply with quote

I don't really like bullet connectors.

I have tried out pretty much all of the common types and find that Anderson's are by far the best.
____________________
Current Bikes:Honda 929RR Fireblade, Honda CD200 Benly (Project), Stomp Z2 140
Electric Bike Project
 Back to top
View user's profile Send private message You must be logged in to rate posts

The Artist
Super Spammer



Joined: 06 Jan 2008
Karma :

PostPosted: 21:42 - 16 Dec 2014    Post subject: Reply with quote

Aff wrote:
I don't really like bullet connectors.

I have tried out pretty much all of the common types and find that Anderson's are by far the best.


Anderson are good. We use them at work for our 48V 400Ah deep cycle packs. I would rather not chop off the end of these battery pack connectors and re-crimp because I don't have a proper crimper for them. I can solder the bullets easily though.

What about the charger/PSU set up, is that ok?
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Aff
World Chat Champion



Joined: 05 May 2011
Karma :

PostPosted: 21:53 - 16 Dec 2014    Post subject: Reply with quote

The Artist wrote:

Anderson are good. We use them at work for our 48V 400Ah deep cycle packs. I would rather not chop off the end of these battery pack connectors and re-crimp because I don't have a proper crimper for them. I can solder the bullets easily though.

What about the charger/PSU set up, is that ok?


I have never seen that charger before, doesn't seem to say a total max power output? :edit: google says 400W

It seems quite good.

At that price you are getting into the realms of the well known chargers like the iCharger and Cellpro series.

I have a few Turnigy bits and bobs though and they seem good quality. I would definitely consider that charger if I was doing it again (I dont think it existed when I started).
____________________
Current Bikes:Honda 929RR Fireblade, Honda CD200 Benly (Project), Stomp Z2 140
Electric Bike Project
 Back to top
View user's profile Send private message You must be logged in to rate posts

The Artist
Super Spammer



Joined: 06 Jan 2008
Karma :

PostPosted: 22:24 - 16 Dec 2014    Post subject: Reply with quote

Out of stock. Sad

Might go for this one.

https://www.hobbyking.com/hobbyking/store/__44532__Turnigy_4x6S_400W_Lithium_Polymer_Battery_Charger_UK_Warehouse_.html Bit more expensive but I am sure that will be enough for me, even with an expanded battery pack in the future.
 Back to top
View user's profile Send private message Send e-mail You must be logged in to rate posts

Aff
World Chat Champion



Joined: 05 May 2011
Karma :

PostPosted: 22:43 - 16 Dec 2014    Post subject: Reply with quote

The Artist wrote:
Out of stock. Sad


Looks like it's in stock in their international warehouse.
____________________
Current Bikes:Honda 929RR Fireblade, Honda CD200 Benly (Project), Stomp Z2 140
Electric Bike Project
 Back to top
View user's profile Send private message You must be logged in to rate posts
Old Thread Alert!

The last post was made 9 years, 105 days ago. Instead of replying here, would creating a new thread be more useful?
  Display posts from previous:   
This page may contain affiliate links, which means we may earn a small commission if a visitor clicks through and makes a purchase. By clicking on an affiliate link, you accept that third-party cookies will be set.

Post new topic   Reply to topic    Bike Chat Forums Index -> Show & Tell All times are GMT + 1 Hour
Goto page Previous  1, 2, 3, 4, 5, 6, 7, 8, 9  Next
Page 8 of 9

 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum

Read the Terms of Use! - Powered by phpBB © phpBB Group
 

Debug Mode: ON - Server: birks (www) - Page Generation Time: 0.13 Sec - Server Load: 0.08 - MySQL Queries: 17 - Page Size: 150.67 Kb