Lithium, and R-Net

Power wheelchair board for REAL info!

POWERCHAIR MENU! www.wheelchairdriver.com/powerchair-stuff.htm

Lithium, and R-Net

Postby Burgerman » 08 Dec 2017, 23:15

Setting motor max volts.

I just advised the same exact thing to a freinds chair as I advised Expresso, (and Snaker did it too). And he is pleased with some extra speed!

Only this time I took note of the actual figures.

A powerchair on typical lead bricks, using R-net has the max motor volts set to 21.4 to 22.4 volts typically. I looked at a few peoples saved settings. The reason for this is to have a constant maximum speed so that as battery volts sag under load theres enough left to steer. Esp when battery is partly discharged. This is essential using lead batteries, and the motors are usually rated for X RPM at 22V. So lets use 22V as the average figure.

A lithium battery does not sag. Its voltage is typically 26V most of the day. You can set the max motor volts to 26.0 in the R-net programming software. Thats 22V up to 26V. 19% higher. Or 19 percent faster! I did the maths several times as it surprised me.

So this means an 8.5mph chair will now go at 10.1mph
A 13kph/8mph chair will go 9.52mph
A 10kph/6.2mph chair, with all this extra torque still intact, will go 7.4mph. (Or almost 8 with slightly bigger tyres).
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Lithium, and R-Net

Postby shirley_hkg » 09 Dec 2017, 05:33

Will the same apply to Dynamic GB ; . . . . the program you used before ? :dirtbike goodpost
shirley_hkg
 
Posts: 3918
Joined: 31 Dec 2010, 13:42

Re: Lithium, and R-Net

Postby Burgerman » 09 Dec 2017, 19:15

Theres no voltage limit. But there is apercentage limit. I showed on here once before. So that a 4, 6, 8 mph brushless chair are all the same, with the headroom percentage altered. So you just need to set the INPUT DEMAND SCALER from 50, 85, to 100. On all 8mph chairs it alredy is set to 100.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom

Re: Lithium, and R-Net

Postby elryko1992 » 09 Dec 2017, 19:17

My DEMAND SCALER was 95 and i set 100. Its work very good my Typhoon 2.
User avatar
elryko1992
 
Posts: 385
Joined: 05 Aug 2016, 21:08
Location: Romania

Re: Lithium, and R-Net

Postby rover220 » 09 Dec 2017, 19:24

elryko1992 wrote:My DEMAND SCALER was 95 and i set 100. Its work very good my Typhoon 2.


Should leave at 95 really as it means the chair doesn't have to slow to turn.
rover220
 
Posts: 1846
Joined: 10 Dec 2013, 19:34
Location: West Mids, UK

Re: Lithium, and R-Net

Postby elryko1992 » 09 Dec 2017, 19:33

I make more settings and i set how i like it. Its work good :) now. If you want i send my settings to see if is good. Give me a PM with your email.
User avatar
elryko1992
 
Posts: 385
Joined: 05 Aug 2016, 21:08
Location: Romania

Re: Lithium, and R-Net

Postby Gnomatic » 09 Dec 2017, 20:34

I need to pick up a programmer so I can do this. :dirtbike
Gnomatic
 
Posts: 2080
Joined: 24 Aug 2012, 17:18
Location: Ohio USA

Re: Lithium, and R-Net

Postby expresso » 09 Dec 2017, 21:34

sounds great - i did raise mines and then lowered it - not sure how safe it was etc, - i have it at 25V - then took it down to 24.5v i think now - - as long as its safe for the motors etc, - wont over heat ?

next time i will put it to 26V and see how it feels - now being winter - wont know - i was out yesterday to do a few things and chair felt fine speed wise - i believe i have hit closer to 11 at times - i do have larger wheels also - i do want to try it at 26v - and see how the turning feels also

BM - My motors are stock 8.5 mp - with the larger rear wheels - i noticed a difference there when i changed them - i should be doing 11 easy i think at 26V ?

my rear wheel is about 16 oversize when i measured - reasone it lifted the rear so much over the stock wheel - for sure 15.5 inches overall - as it wears out - - so 8.5 motors - full lithium and larger rear wheels at 26v - what should i be expecting - closer to 11 easy ?
Quickie 636 - 230ah LifePo4
expresso
 
Posts: 11916
Joined: 10 May 2010, 03:17

Re: Lithium, and R-Net

Postby Burgerman » 09 Dec 2017, 22:02

No your motors wont overheat... They run coolest at speed, its when turning on the spot, or climbing steep ramps that they get loaded and get heated. Amps = heat, Volts = RPM... Tested some for several hours at 72v on the bench, stone cold.

The speed may be 11 at times.
User avatar
Burgerman
Site Admin
 
Posts: 65050
Joined: 27 May 2008, 21:24
Location: United Kingdom


Return to Everything Powerchair

Who is online

Users browsing this forum: No registered users and 280 guests

cron

 

  eXTReMe Tracker