keeping the controller cool

[Philip Lynott]

Hi,

Anybody have any good ways of cooling down the controller?, I live in Ireland so need to keep the controller protected from the rain,

I've tried a pc fan but it hasn't done the trick,

Thanks,

[e-lmer]

Have you looked into peltier coolers?
 
http://cgi.ebay.com/Gigantic-62mm-545-Watt-Thermoelectric-Peltier-Cooler_W0QQitemZ310104062553QQcmdZViewItem

You would have to have a voltage regulator or maybe hook 3 (36V) or 4 (48V) in series.

[Philip Lynott]

I had forgotten about those,
 
That looks like it would do the job but 500 watts may be hard to justify, although i'm sure you wouldn't have on peak power all the time,

One thing I can about the magic controller is that all it's components are really crammed into it's small case - so it overheats and cuts out very easily,

What controller do you have and how do you cool it ?

[e-lmer]

I have the new style controller (yay).

I have it mounted under the top cross member
with the fins horizontal, and have covered the connectors
on the back side with 2 inch shrink wrap tubing.

With the fins open to air flow I have not seen the controller
get hot (but the wires from the battery and to the motor do)

In southern California we don't have to worry about rain too much
(tho we are expecting the one of the two annual rains on Wednesday to Friday)

I have considered molding a silicone  cover for the connector side and
feeding the wires through a grommet in the bottom, but would rather just
not ride in the rain. 

[Philip Lynott]

Thanks e-Imer,


I've put the controller in metal (tea) box, with the heat sink exposed, when it's finshed it should be very water proof,

your right it does stay cool when exposed to the air - even at full throttle,

[e-lmer]

That's brilliant.  I may switch to something like that too!

[keithm]

I live in England and regularly cycle 8 miles a day rain or shine.

I've got one of the regen controllers and was concerned about water entry. At present I have the controller mounted under the rear rack with batterie above. I took the precaution of sealing the cable entry with silicone but it didn't stick very well. After 5 months I've not had an issue with water entry and don't think the controller is getting hot, battery wires do get warm though.
If I have a water issue I'll try the biscuit tin idea as it looks like a good solution.

ATB  Keith

[Philip Lynott]

Hi Keithm,

From the looks of it your the regen controller should be more naturally waterproof then the new one,

The new 'magic' one actually has NO regen by the way, so the GM website has completly false advertising.

What kind of range do you get and whats your set up?,

 I have a 48v 12ah sla pack with a 1000w motor, on a steel mountain bike with inefficient tyres. - I can do 26km/h for 50mins up and down hills. more testing to follow,

cheers for your response

[philf]

Actually, they don't claim that it does regen - the feature advertised is "regenerative braking".  This, the controller definitely has (and it works well).  I actually haven't bothered to see where its dumping the energy in braking mode - my typical rides are pretty flat and without a lot of coasting, so I've never really been that interested in regen.  But the braking effect is nice!

[Philip Lynott]

Hi Philf,

With the 'magic' controller I notice no significant braking from the controller although I know that when I coast some power does go to the batteries.

I'm not sure what the difference between regen and regenerative braking is.

I hindsight I don't think regen braking is a good idea anyway - seems it can damage expensive batteries and is inefficient.

Is there something I don't know about the controller that activates regen braking?

thanks

[Perbear]

Hi Philf,

With the 'magic' controller I notice no significant braking from the controller although I know that when I coast some power does go to the batteries.

Hi Philip,

Remember that your motor needs to be able to work as a generator. If you have a freewheel between motor and bicycle wheel, you will not be able to regen.

IMHO all "minimotors" has a built-in freewheel and will not be able to regen.

Per

[Sangesf]

When I push my bicycle backwards (New 250w Mini Motor from GM) I see power being supplied to the battery (I see the lights light up on the throttle controller without the battery connected) which would mean to me, that the mini motor has the ability to regen w/braking (I don't know about the regen with the new controller, because I haven't received mine yet.)
Two things of notice, given the above statement.
1.) The mini motor isn't truly "freewheel"  It DOES need the ability to reverse FOR regenerative purposes.
2.) The controller (I'm guessing) ALLOWS the "regenerative" property to be applied back to the battery.

Any thoughts on this?  Or am I talkin' out of me arse?

[Perbear]

That means either:

1) I am wrong, the minimotor does not have a freewheel (which sounds likely)

2) When you push the motor backwards without battery, the electric braking resistance (current) is not enough to make the freewheel disengage (which also sounds likely)

To confirm either 1) or 2) you can do this:
Disconnect battery from bike. Then disconnect the three power cables from the motor and short them together temporarily with a loose piece of wire. Then push the bike a short distance by hand. If you can move the bike more easily backward than forward, then your motor has a freewheel. If the motor brakes equally either way, your motor is good for regen. Only move cycle/wheel by hand.

[Perbear]

I have just ordered my own minimotor. Will check freewheeling and report. 

Per