grin cycle-analyst with frankenrunner high wattage technical question

CrossRoads

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I'm hoping there are some nerds on this forum with experience with the grin cycle analyst. I've been mostly pleased with the grin experience so far. Love the rich array of read-outs (TMI maybe) getting good over-all performance, efficiency, the regen is awesome, etc., I just can't seem to get it to max out the wattage.

So I'm running a RH212 with the fast-wind on a recumbent bike with the cycle analyst and the grin frankenrunner, and a 72v nominal battery. Only thing is i can't get more than 1500-1600 watts out of it, at any speed. When i plug these parameters into grin's motor-sim tool, it says I should get 1800 watts at 18 mph and I should be getting 2000+ watts from 25mph to 40 mph. When I'm accellerating, i'm climbing steadily to 1585 or so watts at about 15mph and then the power just plateaus there. Every once in a while i get 1600 watts, but never more.

The speed limit, amperage limit, and wattage limits are all maxed out. I thought it might be the throttle setting. I've tried playing with the throttle output and made sure it was 99% "Through" and the range goes from the maximum spectrum of .85v to 4.24v.

I understand that asking for 2000 watts is a little glutonous. I actually don't really want to go faster than 40mph and the system already does 40 with 1500 watts on flat ground, but it would be nice to have that 25% extra power for accelerating and for steep climbs. I'm hoping there is just a setting to change somwhere. The setup procedures are not super simple, perhaps i am missing something. Other than setting the battery specs and the wheel-size for the accurate speed read-out, and playing with the throttle setting AFTER noticing the issue, I haven't changed any of the factory settings.

I actually have the same issue on my other grin kit which is installed on a cargo bike with a 60v battery, which also should be peaking at 1900 watts at high speed, and again, i'm only getting a max of 1600.
 
I am not a pro in the area of your question, but I do have a suggestion which will help the people here who are better informed than me.

Tell them more about your battery pack. i.e. How many Amp Hour it is, along with its general configuration, such as 19S4P Samsung 21700 50 cells. It uses Lithium ION or LifePo4 cells. Tell us about what your BMS limit is.
Tell them about your controller. i.e. What model is it, what is the Maximum Amps it advertises delivering. I did find the webpage for the Grin Frankenrunner. Many may recognize the "Grin" name, but not have familiarity with specific models in their family. I will provide the link for it at the bottom of this posting.
Tell them about your motor. i.e. It is a mid-drive made by XXXXX brand, model number YYYY. Or it is a Hub Motor made by XXXXX, rated at YYYY Watts.

The Grin Frankenrunner controller seems to MAX out at 2kW, often hitting maximum figures can be tough. I note the Battery connection on it is an XT60, which on paper is good for 60 amps, but functionally is best kept under 50 amps. One of the motor connectors is a "Bullet XT60" which will have the same max current limitation for the phase connections. Check those connectors for signs of burning or arcing.

Keep in mind your Battery Managment System (BMS) could be a limiting factor on peak current. Until we know more about your battery, it would only be a guessing game.

Grin FrankenRunner Link
 
Thanks for your consideration. I was really hoping there might be someone on here deeply familiar with the Grin Cycle-Analyst, because i'm pretty sure that's where the issue is and it's such a particular system that is sort of unlike any other E-bike system. There are so many options / variables with the cycle-analyst, that I figured it might be one of the settings somewhere that i'm missing. I emailed Grin customer support but haven't received a reply.

Your thoughts are still appreciated, i suppose. The battery BMS is rated to 50 amps. 2kw at 84 volts is only 24 amps, so well below that. All the other components are supposed to be able to handle 2kw. The battery i'm using is a Unit Pack Power battery, which is a company with a questionable reputation, so i suppose there's a possibility the BMS is actually limiting the current.
 
whelp, it's not the battery. I went for a test ride on the system with a 72v nominal Li-Fe-P04 battery with 50 amp bms, and same thing, won't go past 1600 watts. FYI it's also the same behavior with two different UPP batteries, a 60v nominal and 72v nominal, both having claimed bms amperages of 50 or 60 amps.
 
Specs on the frankenrunner controller are "87V Max Battery Voltage and 96A Peak Phase Currents". All I'm asking for here is 30 amps. The simulator tool shows 2200 watts output at the peak which is 30A at 72V, or 26A at 84V. I am currently, haha, get it, currently, getting only 20 amps at the functioning SOC voltage of 80v.

In the cycle analyst, the max current, max speed, max power, settings are all up at maximums over 3000 watts. The throttle output signal is at 99% pass-through, ranging up to 4.24v. So i've checked all the sort of normal settings. Pretty out of options at this point. Also Grin guys did write back to me but they basically just said "check the settings".
 
How many amps is your controller? To get 2000w from 72v you'll need at least a 28 amp controller.
 
"Specs on the frankenrunner controller are "87V Max Battery Voltage and 96A Peak Phase Currents"."
 
update, problem solved!!

There are firmware settings on the controller itself which limit phase current and battery current, which are not accessible by changing settings on the cycle-analyst (dashboard computer). So I needed to get an FTDI cable from Grin, download some software, and plug the controller directly into a laptop to change controller limits. After getting the software and cable, the settings took 5 minutes to change and now i have 3000 watts at my disposal.

Funny thing is i inquired with Grin tech support and they never told me this very stupidly simple and useful piece of information.
 
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