Sorry, I completely missed that. It looks like Load Compensation performs something similar on grades
Motor Size Upgrade Question
- Thread starter YellowBuzzaroundEX
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Hillhater
100 TW
Is that an adjustable parameter ?
I thought that an increased load on a brushed motor would result in an increase in amp draw…up to the limit of the controller or battery, ..whichever is the lower .
It looks like a range from 0 to 1020 milliohms, whatever that equates to, but the description makes it sound like you can adjust the behavior under increasing load.
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Solved!
Current Limit setting (parameter) range is 0-40A. Scooter manufacturer stock setting is 40A. It's still set to 40A.
Boost Current (boost amps) setting range is 0-10A. Scooter manufacturer stock setting is 10A. It's still set to 10A. This means the controller can briefly increase current (amps) by up to 10A as needed to help climb obstacles.
40A Current Limit + 10A Boost Current = 50A Total amps to motor when going up/over obstacles. Boost only happens for number of seconds specified in Boost Time setting.
Boost Time scooter manufacturer default is 4 seconds. Two years ago I changed it to 2s because I figured it only takes 1s for a tire to get up and over the 2 inch vertical lip of the many poor quality ramps in my town. The 2s Boost Time setting is my problem!
It boosts amps for 2s, but it takes 5s to 10s to drive up the short steep hills in my area. If I increase Boost Time from 2s to 10s or 12s then it'll climb those hills just fine (with the motor I already have)!!!
Maximum Motor Voltage scooter manufacturer setting is 28.8V. I left it at 28.8V (because the batteries would become the limit if this setting were too high).
Load Compensation range is 0-1020mΩ. What does mΩ mean? Load Comp can briefly increase motor voltage up 10V more than Max Motor Voltage setting as needed to help climb obstacles.
28.8V Max Motor Volts + 10V Load Comp (boost volts) = 38.8V Total volts to motor when going up/over obstacles.
Solution
So I need to increase the amps (current) Boost Time seconds. That will improve hill climbing 20%. Then if needed, I can also slightly increase Load Comp (volts boost) setting, but I don't think I'll need to.
IME it's best to not increase Load Comp (volts boost) unless it's really needed because increased Load Comp tends to give less smooth, less subtle (jerkier) control of throttle/acceleration/speed, especially when at low throttle (such as when indoors).
Boost Current (boost amps) is already set to its 10A maximum. So nothing to change there. I'm glad I don't need to increase it because increasing Boost Current could result in less smooth, less subtle (jerkier) control of throttle/acceleration/speed.
I will be increasing amps Boost (current) Time. I think this is safe because it will not affect throttle/acceleration smoothness, finesse. Too much Boost Time could overheat batteries, but I'm only increasing Boost Time to 10 seconds. So it looks like a safe solution, IMO.
I have no concerns that increasing Boost Time could overheat the motor because even during Current Boost the total amps to motor is only 50A. My other, larger, heavier scooter uses same motor with a more powerful controller that sends 70A to the motor.
I'll increase current Boost Time to 10 seconds when my laptop is functional again next Friday. My laptop is another fix it project.
Current Limit setting (parameter) range is 0-40A. Scooter manufacturer stock setting is 40A. It's still set to 40A.
Boost Current (boost amps) setting range is 0-10A. Scooter manufacturer stock setting is 10A. It's still set to 10A. This means the controller can briefly increase current (amps) by up to 10A as needed to help climb obstacles.
40A Current Limit + 10A Boost Current = 50A Total amps to motor when going up/over obstacles. Boost only happens for number of seconds specified in Boost Time setting.
Boost Time scooter manufacturer default is 4 seconds. Two years ago I changed it to 2s because I figured it only takes 1s for a tire to get up and over the 2 inch vertical lip of the many poor quality ramps in my town. The 2s Boost Time setting is my problem!
It boosts amps for 2s, but it takes 5s to 10s to drive up the short steep hills in my area. If I increase Boost Time from 2s to 10s or 12s then it'll climb those hills just fine (with the motor I already have)!!!
Maximum Motor Voltage scooter manufacturer setting is 28.8V. I left it at 28.8V (because the batteries would become the limit if this setting were too high).
Load Compensation range is 0-1020mΩ. What does mΩ mean? Load Comp can briefly increase motor voltage up 10V more than Max Motor Voltage setting as needed to help climb obstacles.
28.8V Max Motor Volts + 10V Load Comp (boost volts) = 38.8V Total volts to motor when going up/over obstacles.
Solution
So I need to increase the amps (current) Boost Time seconds. That will improve hill climbing 20%. Then if needed, I can also slightly increase Load Comp (volts boost) setting, but I don't think I'll need to.
IME it's best to not increase Load Comp (volts boost) unless it's really needed because increased Load Comp tends to give less smooth, less subtle (jerkier) control of throttle/acceleration/speed, especially when at low throttle (such as when indoors).
Boost Current (boost amps) is already set to its 10A maximum. So nothing to change there. I'm glad I don't need to increase it because increasing Boost Current could result in less smooth, less subtle (jerkier) control of throttle/acceleration/speed.
I will be increasing amps Boost (current) Time. I think this is safe because it will not affect throttle/acceleration smoothness, finesse. Too much Boost Time could overheat batteries, but I'm only increasing Boost Time to 10 seconds. So it looks like a safe solution, IMO.
I have no concerns that increasing Boost Time could overheat the motor because even during Current Boost the total amps to motor is only 50A. My other, larger, heavier scooter uses same motor with a more powerful controller that sends 70A to the motor.
I'll increase current Boost Time to 10 seconds when my laptop is functional again next Friday. My laptop is another fix it project.
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Hillhater
100 TW
I am curious to understand how a brushed motor controller can increase the motor voltage above the max battery voltage ?
Also, Torque, for hill climbing, is determined by amperage rather than voltage (speed) ,..
Please let us know how it works out.
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Thanks. I don't need a larger motor. I just need more current to the motor I already have. Increasing current Boost Time from 2 to 10 seconds will keep the current boosted all the way up the short, steep hills. It's an easy, free solution!I’m glad you figured it out. Thanks for sharing your progress. I’m learning a few things from this thread
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I too am curious how the controller does that. Can anyone explain this? Perhaps the controller has a capacitor?
The controller manual says in the Maximum Motor Voltage section 4.4.5.13 page 85 in a note it says Load Comp setting can increase voltage to motor up to 10V above the 28.8V Max Motor Voltage setting.
I explained what the manual says the controller does and its relevant settings. You can read it for yourself. I don't know how it accomplishes these things.
I'd love it if someone could explain how the controller does the things its manual says it does.
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With All do respect, I think you are skirting skin loss territory. You do know that you elevated the vehicle's CoG by installing larger rubber... in addition to increasing it's top speed.
My 90 YO father was contemplating similar modifications to his scooter. To curb his enthusiasm, I built him a safer, more suitable platform.
A straight forward conversion that yielded a 65 pound, 12mph grocery getter. The original transaxle was retained, in addition to the OEM coupling to separate into two chunks for ease of loading and transporting. Seat was lowered to 18" and rear track increased 3". A pair of Milwaukee V28 cordless drill batteries in parallel supplied the go juice.
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You made a very interesting and fast scooter. That's the most castor/rake I've ever seen on a front wheel. It must have very stable, sedate steering.
However, what you made is way too low for me to get on. I have very bad knees.
I didn't mention it earlier, but my cousin lowered my seat post 3 inches. To do that he cut the post shorter and drilled a new mounting hole. My seat height above the ground is 1.2 inches lower than stock.
So my COG is slightly lower than stock even with the larger/taller tires. Yet still high enough for me to get on and off even with bad knees. Also, my swivel seat function is retained. I need a swiveling seat for easy on/off. The seat is locked facing forwards when driving, or locked sideways when getting on/off.
It's stable when careful cornering. If hard cornering I learned to slow down and/or lean my body into corners. It's been working well for me for 3 years. I don't think most handicapped people could safely drive it, but I do fine with it.
Notice the low seating position (for a mobility scooter), car horns mounted under front basket, pneumatic tires and coil spring suspension.
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Hillhater
100 TW
You may find this interesting..
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I'm familiar with Mobility Direct & Dakota batteries.
Mobility Direct is putting two 12V Dakota brand LiFePo4 batteries in series to make a 24V system. I'm doubtful that two 12V LiFePo4 batteries in series will stay balanced nor live a long life.
I think it'd be more reliable and safer to use one 24V LiFePo4 battery if it will physically fit in battery box. If battery box physical layout requires two batteries, then use two 24V LiFePo4 batteries in parallel. Either of these is more likely to stay balanced and live longer service life.
That advice is from two LiFePo4 battery technicians I talked with at two different battery companies.
As for Dakota batteries... I watched videos on an icefisherman's blog where the guy is also an electrical expert. He tested and disassembled various brands of LiFePo4 batteries. Dakota tested poorly and failed various safety tests.
Hillhater
100 TW
LfP is more likely to stay balanced than a pair of AGMs !
A they are also proven to outlive AGMs By a huge margin .
PS.. iwas not suggesting any specific brand of battery, just to show the advantages of LFP over AGM.
LewTwo
1 MW
Nice work. Did you by any chance do a 'build thread' on that ?
Thank you...
Sorry, no build thread on that one. It was done at least a decade ago IIRC. I might have another image or two... I'll check.
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On my mobility scooter there's 1 charging plugin for a 24V charger that charges two 12V batteries in series. This is my source of concern about batteries balance.
If I could charge each 12V battery separately at 12V each, then I'd have no concern about two 12V batteries in series staying in balance; but the battery box has only one plug, which necessitates using a 24V charger.
My solution (if I someday upgrade from AGM to LiFePo4) would be to use two 24V 12AH batteries connected in parallel because that would be easiest to keep balanced when using a 24V charger plugged into tiller (steering column).
24V 12Ah lithium battery - LiFePO4 Canada - Free Shipping!
24V 12Ah lithium battery for deep cycle applications including electric wheelchairs and mobility scooters. LiFePO4 free shipping Canada-wide!
www.canbat.com
Even better would be to use one 24V 25AH battery, if it'd physically fit in my battery box. But my battery box requires two smaller batteries to physically fit.
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My Dynamic R series 50A controller is 40A Max for up to 20 seconds + 10A Boost for 0-8 seconds. After 20 seconds it drops down to 25A limit for 30 seconds for motor cooling.
I updated my controller's Boost parameter from 10A Boost for (up to) 4 seconds to 10A Boost for (up to) 8 seconds. This helped a little bit for driving up a steep dike, but it doesn't help enough.
It needs lower gearing. I'm going to reduce tire diameter from 10.4" to next smaller size.
I updated my controller's Boost parameter from 10A Boost for (up to) 4 seconds to 10A Boost for (up to) 8 seconds. This helped a little bit for driving up a steep dike, but it doesn't help enough.
It needs lower gearing. I'm going to reduce tire diameter from 10.4" to next smaller size.
Chalo
100 TW
I didn't read the entire thread to see whether this has been covered, but it seems to me that if your controller will tolerate an extra 15V, you can just add another 12V battery in series (or its equivalent) to increase both top speed and torque.
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According to the owner's manual...
The Dynamic R50 controller usually operates around 24V. It says that when climbing hills/obstacles it can temporarily increase voltage +10V up to 36V total via its Load Compensation feature. This means the motor sometimes briefly operates at 36V, which is the max the motor is rated for.
The Dynamic R50 controller can briefly increase voltage +10V to total 36V. It can also briefy boost amps +10A to total 50A. How does the controller do these things when the scooter AGM battery pack is 24V?
In any case, I think the motor is already at, or near, its limits. Hopefully not past its limits.
Also, there's no room to add a 3rd battery.
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