back emf damages sla batteries?

[solarbbq]

Have been riding around in my electric trike for about 1 and a half years now.

Was using standard car batteries, no diodes on motors so back emf everytime I turned

motor on/off went into the batteries. Batteries about 4 years old, my theory is that

the back emf may have helped to de-sulphate the batteries.

Am upgrading to better batteries soon probably sla glass fibre mat type or gel cell.

Anyone any knowledge on if back emf will harm these batteries?

Generally back emf may be between 20 to 50volts (that a bit of a guess ).

I may be way off the mark there.

Was using tape drive motors (amatek 40v)to power my trikes, just changed to hub motor, specially made motor which replaces bike wheel hub, very efficient motor.

Have motors running on 36v, 3 batts in series.  

[JeroenH]

Have been riding around in my electric trike for about 1 and a half years now.

Sounds cool! Do you have any pictures of it?

[Norm]

  Why upgrade to better batteries maybe you could

slip a junk car battery in there and

desulphate it?...be nice  to desulphate

batteries while you were ridin' around.

  There was a electric car in Popular Science

once controlled the speed also dynamic brakine

by using a variable speed drive...like in a

snowmobile, which the claimed gave it better

mileage between charges.

               ( :>) Norm.

[solarbbq]

there are two pics of my electric trikes on my website:

www.users.bigpond.com/solarbbq

i've just recieved a hub motor from china, damn its cool, the trikes fly now,

and i'm using about half the current I was using before.

It came with a pwm speed control unit but since its brushed motor I just have it full

or full off that way you dont loose a couple of volts which the controller uses ,

been worth the wait

only prob. with using back emf to desulphate is you would need two good batteries and one oldie (need 36volts to run the trikes), i'm gonna go for some nimh batts i think. Its just a theory that the back emf desulphates, i'm surprised how long the batteries have lasted. Most people would just put some diodes in to stop back emf but

what the heck it certainy hasn't been a detriment to the life of batteries.

I have used them over the last 4 years but only in last 1 and 1/2 years have a had

really reliable trikes. Took   a few years to get em up to speed.

[hiker]

no pictures on this end[went to your site]

just the one at the top of page--looks like a real --easy rider--

nice trike..

whats your top speed and max milage..

[solarbbq]

fixed up pics on website should be ok now,

top speed 25km/h on flat in good conditions, typically around 20kmhr.

range: 7km before recharge using standard small car batteries and discharging them

by 20% (40amphr batts, so 20% discharge means i get 7km for 8amphour batt).

Have just put in hub motor there is speed increase and big range increase but no hard data on it as yet.

will put some video on website in coming days