C5ALIVE Forum

C5 Help => C5 Support => Topic started by: dansretropod on 05, September, 2012 - 14:55:48

Title: 2nd Battery Upgrade
Post by: dansretropod on 05, September, 2012 - 14:55:48
Hello everyone,

I'm new to the site and have recently got my first C5 which is great fun driving around in:)

Just 1 question, what are the advantages of using a 2nd battery, I know it can extend the range, but would it also help when going up hills as at the moment my C5 struggles with hills which I believe is normal.

Thanks!

Dan
Title: Re: 2nd Battery Upgrade
Post by: kamilb1998 on 05, September, 2012 - 17:07:30
It would extend your range but unfortunately won't help with climbing hills. For that you need a 24V conversion which wouldn't be legal anyway.
Title: Re: 2nd Battery Upgrade
Post by: mhurt on 05, September, 2012 - 17:17:19
Could possibly go for the dual motor approach that Chas made http://c5alive.co.uk/forum/index.php/topic,2402.0.html
Not sure that would be entirely legal though, but it's something I'd definitely like to try at some point in the future, as I have to get out and push on some local hills.
Title: Re: 2nd Battery Upgrade
Post by: C5 ENTHUSIAST + RESTORER on 05, September, 2012 - 20:27:16
Hi there talking of my 2 motor C5 I will be putting it up for sale soon
Title: Re: 2nd Battery Upgrade
Post by: mhurt on 05, September, 2012 - 20:56:28
Damn - the missus would kill me if I bought another (not to mention the bank manager!).
Will keep an eye out though, as I know someone that's after one since they tried mine out :)
Title: Re: 2nd Battery Upgrade
Post by: coverman on 06, September, 2012 - 10:28:21
Having two motors means 500W, twice the legal limit.
Title: Re: 2nd Battery Upgrade
Post by: dansretropod on 07, September, 2012 - 08:41:15
Hi,

Thanks for all the advice guys, I'll stick with the standard 1 motor + 1 battery setup. There's only the occasional steep hill/speed bumps where I live so it's no big deal pushing it.

I imagine trying to pedal a C5 with the extra weight of 2 batteries and 2 motors is hard work anyway.

Thanks!
Title: Re: 2nd Battery Upgrade
Post by: coverman on 07, September, 2012 - 12:09:17
I live in a hilly area and just keep pedalling whilst the motor is running
Title: Re: 2nd Battery Upgrade
Post by: mhurt on 07, September, 2012 - 12:26:07
Quote from: coverman on  07, September, 2012  - 12:09:17
I live in a hilly area and just keep pedalling whilst the motor is running

So do I, but the flipping things are too long or too steep (or both!) for that to work :)
I usually have a 100m stretch where I have to push, or extras if I have to stop going uphill for some reason. I'm considering a couple of options that would get me up these, but at a slower speed (around 4mph) and not using the C5 motor
Title: Re: 2nd Battery Upgrade
Post by: dansretropod on 07, September, 2012 - 17:31:05
Yep, some hill's you can't get up even by peddling and using the motor;)  I may look into getting a lighter battery such as the LiFePO4 batteries which are much lighter than a lead acid battery, though much more expensive:(

QuoteI'm considering a couple of options that would get me up these, but at a slower speed (around 4mph) and not using the C5 motor

I like the idea of getting the C5 to go slower up steep hills you'll have to keep us posted.
Title: Re: 2nd Battery Upgrade
Post by: kamilb1998 on 07, September, 2012 - 19:25:55
Quote from: dansretropod on  07, September, 2012  - 17:31:05
Yep, some hill's you can't get up even by peddling and using the motor;)  I may look into getting a lighter battery such as the LiFePO4 batteries which are much lighter than a lead acid battery, though much more expensive:(

QuoteI'm considering a couple of options that would get me up these, but at a slower speed (around 4mph) and not using the C5 motor

I like the idea of getting the C5 to go slower up steep hills you'll have to keep us posted.

I've never had a problem getting up a hill, even if really quite steep, and I very rarely pedal. I nearly always carry two batteries at 32kg and am 9 stone myself.
Title: Re: 2nd Battery Upgrade
Post by: mhurt on 07, September, 2012 - 21:16:42
Quote from: kamilb1998 on  07, September, 2012  - 19:25:55

I've never had a problem getting up a hill, even if really quite steep, and I very rarely pedal. I nearly always carry two batteries at 32kg and am 9 stone myself.

I'm 6 stone heavier than you, just about 41 and, until a couple of months ago hadn't ridden in 25 years :D
I'm sure that after a while, I'll get more strength and stamina, but even then there will be periods where I have problems due to a health condition, so I could still do with a solution eventually :)
Title: Re: 2nd Battery Upgrade
Post by: Robosoft on 08, September, 2012 - 22:49:49
Quote from: coverman on  06, September, 2012  - 10:28:21
Having two motors means 500W, twice the legal limit.

Is that true ???

the top speed would be the same. it would just have more torque (given an illusion of more speed up hill).   

if you had 2x c5 strapped to each other the top speed would be the same.  each motor can't go any faster than 250w unless more power was introduced.

So I say it legal.

If still not sure just peel off the 250w stickers and replace them with 125w.



Title: Re: 2nd Battery Upgrade
Post by: coverman on 10, September, 2012 - 10:01:52
The legal power limit is 250W.
Separately, yes two motors would obviously give twice the torque and twice the power, and therefore collectively may pull a few more revs allowing marginally higher top speed on standard gearing, also illegal.. Again ,obviously, if geared up, a higher top speed yet would be facilitated.
The increased power of two motors wouldn't give an apparent increase in speed up an incline, it would give an actual increase in the speed.
Title: Re: 2nd Battery Upgrade
Post by: Karl on 11, September, 2012 - 11:02:24
Quote from: Robosoft on  08, September, 2012  - 22:49:49


So I say it legal.



A guide to some of the rules, that are always changing,  are found here;
http://c5alive.co.uk/forum/index.php/topic,1074.0.html

Fortunately for us the recent pedelec changes are not retrospective so we do not have to fit the Dutch style pedal sensors etc.

I would suggest that fitting two motors would push you outside the guidelines in both power and weight.


Title: Re: 2nd Battery Upgrade
Post by: Robosoft on 11, September, 2012 - 21:32:33
Still not convinced.

so if i got 2 250w speakers and put them on full would it be louder? as in 500w  or 270w- 300w.

Im guessing 2 x 250w running at same time on the same axel will just give you 250w power but more efficient as the torque is higher. 

i put it another way 250w would give you   2000rpm (totally made up rpm)   put two next to each other would give 2 x motors running at same speed / rpm.  bolt them together on the same axel 1 will run at 2000rpm and the second will run at 2000rpm  not 4000rpm.

So if the law is 250w max (2000rpm)  i would, as said remove the label and replace it with Dual Motor system equivalent to 250w.   And yes it would be faster and you would also have to put a limiter on it to stop it going over the max speed limit.  and yes you would have to make sure the two motors didn't weigh to much.

But at least you would get up a hill as the limiter will allow more power as the c5 slowed.

But what do i know!
Title: Re: 2nd Battery Upgrade
Post by: coverman on 12, September, 2012 - 11:12:47
The foregoing was elementary physics being misunderstood.
Put simply;2 motors =doubled torque & power=increased pulling power=increased speed on given gradient for given weight and ambient conditions. Raise the final drive ratio and the increased power would result in being able to pull the higher gearing hence somewhat higher speed. On a level road at least the top speed would increase as a result.
Oh and by the way, decibels levels are not linear.
Title: Re: 2nd Battery Upgrade
Post by: coverman on 12, September, 2012 - 11:16:55
Oh, oh, having 2 speakers instead of one won't increase output, they don't supply the energy, they just convert it into sound and heat.
Title: Re: 2nd Battery Upgrade
Post by: mhurt on 12, September, 2012 - 12:10:43
I'd be willing to risk it, but it would run on a small battery (my current one is 17kg and is probably overkill for my use :) ), and separate switch purely for a couple of hills I have to get up.

Mounting the drive wheel is something I need to look at, as I'm not sure how Chas did it (probably screwed on), but it's not something that's on the immediate horizon.
Title: Re: 2nd Battery Upgrade
Post by: Robosoft on 12, September, 2012 - 20:09:02
Just do it.

Whats the worst they can do.

No Points - its not a car, Confiscation? (at best they will ask you to remove the extra motor and get VOSA to verify it) or small fixed fine.   

I'd still go with the sticker method (Sinclair Dual Motor System MAX power 250w Should do it).   "I got the c5 like this! I assumed it was legal"

I still think if you put my argument in front of a judge (it will never come to that) providing you wen't going to fast and the weight was within tolerance you would be fine.

If you need to. you can call me from the jail and i'll post bail money.


Title: Re: 2nd Battery Upgrade
Post by: Lancealot on 12, September, 2012 - 22:29:19
If you are not going to be doing 20-30mph and only have it at max 15mph you will be ok, but just for torque.

I have been stopped by Police 3 times to only ask were did I get it, how much and I have not seen one of them since I was a kid or for the younger ones - my dad had one!!!!!!!!!!!!!

I even live next door to a transport cop and he has not said anything even when I have the kids sitting infront of me.

Most people don't know what they are or have uderneath so having  1 or 2 motors won't be a problem.

Lance
Title: Re: 2nd Battery Upgrade
Post by: coverman on 13, September, 2012 - 09:30:31
God forbid you should have an accident involving injury wth a two motor version.Then you'd find out about the law.
Title: Re: 2nd Battery Upgrade
Post by: Robosoft on 13, September, 2012 - 20:34:48
Everyone still has a story about c5 so your's could be

"mine is the c5+ prototype that they did just b4 they went bust! - if you don't believe me officer give sinclair a ring"

Like yesterday i had a customer come in an tell me he has the very on that was on tomorrows world in his shed.  (our 2 c5 are in the shop) He didn't just come in and say that for no reason.

I pointed him to this forum.  He said that his staff used to use them for the paper round as he had a newsagents.






Title: Re: 2nd Battery Upgrade
Post by: Lancealot on 17, September, 2012 - 19:15:47
Get in there quick offer a good cheap price............................

Lance