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Upgraded 35 Amp Controller Bolt on Area 13 Protect your battery!!!

Started by MJLStickMan, August 25, 2022, 07:39:00 AM

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So wanted to let the community know about my experience with this controller. Since Rad went with the 13.5 Ah battery the amount of watts you can pull from this stock battery is limited to 750 Watts with the old 20 amp controller. This is actually for good reason because if you try to draw more power from this battery with the 35 amp controller it gets upset to the point the battery will not charge correctly. So whats the point in getting a 35 amp controller then. The point is finding the sweet spot which is 28 - 30 amps max draw which can be adjusted in the hidden menu of the controller labeled CH5 which I have set to 4 or 5. This video explains all the settings in the menu If you set this any higher than 5 then you will have problems charging your battery after use. Prolonged use of battery at CH5 = 6 damaged my battery beyond repair. I love Rad. The damage to the battery was my fault and they still replaced the battery for me which is Rad going above and beyond for obvious reasons. If you set CH5 = 6 then the controller will draw upwards of 1500 watts which the battery is not capable of sustaining without hurting the cells.
I never use CH5 = 6 with my new stock battery because I know the consequences instead I have dual batteries the other being a 52V 19.5 Ah battery that can cope with the higher amp draw with CH5 = 6 or 7 which is way fun sport mode.


Interesting, thanks.  I've been running with C5=0 on my MiniST2 and happy with it, but will try C5=5 and see how that feels.  I typically recharge in the 2-bar range, but often with more in the tank than that.

EDIT: back from a 5-mile test.  With C5=0, I can pull a maximum of about 1580 watts, setting it to 6 limited it to about 1250 and setting to 5 gave me about 1150.  Both of those would probably be fine in most circumstances, but I really hated the 100% immediate application of power from a stop rather than the fairly-smooth ramp of setting 0 - almost dumped my front wheel into a hedge when cornering on a sidewalk at very low speed, as it leaped forward in PAS 2.  That's a problem on tight, lumpy or slippery trails where a gentle application of power is necessary, so I went back to 0.  This controller isn't as smooth on the ramp-up as the stock Rad tuning, but it's pretty good.

I moderate my usage and hold full-power in abeyance for those times it's really needed for a bit; usually draw in the range of 500-800w, occasionally hit 1,000 so I think as long as I keep my power draw under control my battery should be fine. 

Altema here on the forum has done brutal motor testing with these controllers and said even when trying to burn out a stock Rad "750w" motor under repeated and lengthy full 1600 watt loads he was unable to do so, and as far as I know has not reported any battery issues, although maybe he just hasn't charged it enough times to notice.  I believe he, like many of us, tries to keep battery level between about 25-80% unless setting out on a long ride where 100% is useful. 
Shucks Ma'am, I'm no "Hero Member", I just like to wear this cape.

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