Rize RX – Hits and misses new owner version

I'm looking for feedback on the RX battery. Now, it may be that it's performing as it's supposed to but I feel that it looses percentage rather quickly. I've charged it to 100% and ridden it in PAS 1 up a gradual hill (nothing steep) for about 2.8Km. I'll arrive at my work and the battery will have lost between 3-5% of its charge. Maybe this is normal but I'm reading other posts where battery percentage holds around 100% for awhile before dropping off. Are all batteries (of the same Ah and W) equal or can there be variation between?

I'd love to know what other RX or RX Pro riders are usually getting for their range? Do you find your percentage drops immediately or holds and then drops? How far are you getting on a charge (starting % - trip - ending %).

As well, I can't seem to make sense of voltage. I was down to 22% but my voltage was at 47.3v. Looking at the battery v/% chart I would have thought it would be closer to 43v. On another ride I was at 33% and my voltage was at 47.8v.

Any feedback would be greatly appreciated.

Thanks!
 

theemartymac

Active Member
I'm looking for feedback on the RX battery. Now, it may be that it's performing as it's supposed to but I feel that it looses percentage rather quickly. I've charged it to 100% and ridden it in PAS 1 up a gradual hill (nothing steep) for about 2.8Km. I'll arrive at my work and the battery will have lost between 3-5% of its charge. Maybe this is normal but I'm reading other posts where battery percentage holds around 100% for awhile before dropping off. Are all batteries (of the same Ah and W) equal or can there be variation between?

I'd love to know what other RX or RX Pro riders are usually getting for their range? Do you find your percentage drops immediately or holds and then drops? How far are you getting on a charge (starting % - trip - ending %).

As well, I can't seem to make sense of voltage. I was down to 22% but my voltage was at 47.3v. Looking at the battery v/% chart I would have thought it would be closer to 43v. On another ride I was at 33% and my voltage was at 47.8v.

Any feedback would be greatly appreciated.

Thanks!
The percentage reading is all but useless. The voltage chart method is better, but it is still affected by temps, etc, so the battery will spike back up a volt or two after your park for a few minutes. Peoples charts tend to vary by up to 10% but 47V is definitely still at or above 50%. 48V batteries should charge up to roughly 54V full, and <40 Volts is functionally 'dead' and approaching the cutoff voltage.

My RX battery drops off very slowly, but my RX Pro with the color display drops off far too fast. Each bike will still get near the rated 100+km range on PAS 3 if I'm contributing at least half the 'assist' myself. I am certain I can easily exceed 100km if I use PAS 2 and ride responsibly (but what's the fun in that? ;-) ).
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
At 150 miles or so, I don't have that many charges on my bike yet, but I did notice one charge where the voltage seemed to drop off quicker than I thought it should have. Radio control experience taught me to be suspicious of cell balance in cases like that. That there are some cells that are not completely charged among those that are fully charged. Anyway, I put the charger on and let it go to green, unplugged it, let it sit overnight, and plugged it back in. Sure enough, it took more charge. That's not that unusual for new batteries that haven't been used/charged much and it hasn't happened since.

Agree watching the voltage (vs. battery %) is the better plan. I charge at 46v. There's not much left at that point, and I don't have to worry about voltage sag kicking out the LVC (turning off the power) when crossing a busy road for instance.

Cold weather doesn't help a darn thing either....
 
Thanks for your replies. So just to clarify, if my percentage reads say, 22% but my voltage reads around 47v, I should go with the voltage over percentage and assume I have more in the tank than the percentage alone suggests?
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
If you understand that the bike is going to shut down/quit at 40-42v, you can see that at 22% indicated or 47v indicated, depending on which you get used to using/looking at, you can suit yourself. There's just not a lot of battery left either way you look at it!

FWIW, many avoid riding the battery down to exhaustion as it's generally agreed it's hard on the battery from a longevity standpoint. Worse, if you ride it until it quits and your a few miles from home - you're going to have a long ride.
 

theemartymac

Active Member
This is just my own strategy, but I might suggest that you ride the bike at least once until you begin to notice the power decline. Due to the shape of the power drop off curve with lithium batteries, at higher assist levels it will be pretty obvious and noticeable once it truly enters the last 20%. Once it starts to noticeably drop off, you can still expect to get 10-15kms anyway at low assist levels. When I tested my RX this way on a long 80km ride at average of PAS 5, it started to noticeably decline at 65kms. I made it home fine staying at PAS 5 with very little assist left. It still showed 20%, and read 42v after I parked it for 5 mins and unpacked, and I did even crank it up to max PAS 6 for the last 1/2km of the ride and gave it full thumb throttle on top of my own pedaling and it didn't cut out (motor still pushed quite hard too, but I could feel it fading in real time). While I did not have any cutouts, I suspect I was getting close at that point, and didn't feel the need to risk damaging the battery.

I also did another 80km test ride at PAS 3, and I was able to finish at 35% and just about 45v. I normally try to keep the battery above 45V/40% whenever I can for longevity, but I have total confidence that I can run it down to 42V in a pinch. Most battery kits seem to be dialed to cut out somewhere between 36V and 40V, but as AHicks suggested that can happen suddenly if you try to goose the throttle and it dips below that point momentarily. If you start to notice the power drop off unexpectedly on a normal ride, just lower your PAS level and ride conservatively (no hard launches or steep hills), and I'd be confident you can squeeze a fair bit out of it at a consistent pace before you are stuck riding old school style.
 

theemartymac

Active Member
Here is what a lithium battery curve looks like for a newer 52V battery. A 48V will be about 4-6V lower across the graph, and this is slightly exaggerated for illustration purposes. You can see the power drops off fast after 80%, and never actually reaches zero due to the voltage cutoff. Since any voltages above 48V generally won't be felt (the stock controller won't overvolt unless you unlock that), you won't notice the drop off at all until you are under 20%, but then it should be quite obvious. This is why newer 52V batteries are popular with 48V motors as they give you an extra 10% or so above 48V before they noticeably decline. The overall range doesn't change much as the cutout voltage also rises by 4-5V, but they maintain that ideal power output for longer. https://www.powertechsystems.eu/wp-content/uploads/sites/6/2018/11/LiFePO4-vs-Lead-Acid-Discharge-Curve-EN.pngLiFePO4-vs-Lead-Acid-Discharge-Curve-EN.png
 
Blessed with great weather (around 65 and sunny) here in central NC. Cleaned up the bike a bit and charged the battery a bit this AM then went on a 15+ mile tour. Bike performed well, tons of people on the greenways, so lots of slowing down, speeding up and dodging all manner of people/dogs/bikes/kids...etc.
Really great to get out, had been working too much and playing too little with good weather to ride.
Slight shifting issue in the middle gears, but I will adjust it tomorrow as I expect another great day to get in a small ride. Should be able to ride over to my tennis match at 2pm.
Hope some of you are getting out as well.
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Re: shifting issue, IMHO, these 9 speeds are a pain in the butt to dial in. Seems like you get one side or the other PERFECT and the other side, or the middle gears, are maybe not so perfect! On my bike, (Pro RX) a 1/4 turn of that adjusting nut can make a noticeable difference when trying to dial in to the point where all 9 gears shift quickly with no dragging on the way up, or down!

I find 7 speeds FAR more forgiving in this respect. Almost worth converting to 7 speed for that reason. I never use all 9 anyway... -Al
 

McCorby

Well-Known Member
Hmm, I have a Deore XT 9 speed that shifts up and down all the gears great. I’ve only had to adjust the cable adjuster two or three times in over 2500 miles. No other adjustments have been necessary. What derailleur do you have?
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Don't remember specifically. Supposed to be Shimano's best 9 speed.
 

McCorby

Well-Known Member
Then there must be something wrong with your setup. Shimano’s premium 9 speeds are pretty bulletproof.
 
2 things...

1. I find that when I'm riding in PAS 1 my range will be less than when I switch to PAS 2 or 3. For instance, in PAS 1, the range might show 30km with 50% of the
battery gone but if I go into PAS 2 it will read upwards of 50-60 kms. Does anyone have an idea of which 'range' reading is more accurate? Any ideas of why it does this?

2. My battery voltage reading is never anywhere close to what various charts suggest. For instance, many charts show that when battery reads roughly 25% the
voltage equivalent is around 42v. My voltage reading does not ever seem to drop below 46v and my battery was down to 8%. At 20% it's usually at 47v. Does anyone know the reasoning behind this? Is this something to be concerned about or is the voltage reading not a very accurate way to read the life of the battery.

Thanks
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Re: range. I don't use it much, but the manual says the reading indicated will have a direct relevance to your last few minutes of riding (load, speed, etc.). My thought is there's an algorithm in the form of a mini trip computer in play. At best, stuff like that is just going to give you a "best guess". Not intended to be anything exact.

That said, at about 250 miles now, I'm STILL getting used to my bike, and have found something similar to what you are saying regarding the 2 and 3 PAS levels. I just can't get my head wrapped around exactly what's going on. I don't see the expected wattage increase at cruise speeds unless pedaling pretty hard. It's almost like just the max amount of available power is changing, with much less effect as pedal effort is decreased. I'm in the hills a lot so it's harder to gauge there than if I were riding the flat lands more. Getting max mileage is a game I play with myself, so I watch what's going on here pretty closely too.

Re: voltage reading. At 47v/20% you're approaching that steep drop seen on the battery charts. You have about 20% of the battery's range available. Below 45v, you risk the battery sagging to the point it's going to shut off the power if you try anything that's going to draw a lot of power. Like a full throttle burst across a busy road, or climbing that last big hill prior to arriving at you home/destination. If you cool it at 45v, using a minimum amount of power, you can actually make it several more miles if necessary. I avoid using anything below about 45v if possible. Mine is charged at 46v. That's me though. I ride for pleasure only, and the range I get riding from 54v to 46v is an easy 35 miles. That's plenty for my purposes, no point in pushing it further riding at lower voltages. -Al
 

Deacon Blues

Well-Known Member
Good luck with the weight loss... I was 246lbs 3 months ago and am 222 now trying to get to 200 ...at 61 years of age.... i think i would get more out of the battery if I can continue to lose the weight.
I decided to go on a diet last July when I hit 197 pounds (I'm 5'8"). In my running years, when I was in my 20s and 30s, dropping weight was easy, but at 69 years of age it's been a slow struggle. The good news is I'm down to 157 pounds. 🥳 The bad news is I now have to maintain that weight. That means NOT going back to my old eating (and drinking) habits, and that's going to be tough.
 

Brad1999

New Member
Good luck with the weight loss... I was 246lbs 3 months ago and am 222 now trying to get to 200 ...at 61 years of age.... i think i would get more out of the battery if I can continue to lose the weight.
Lol I've gain weight since my ebike purchase ,too much throttle I even been using my regular bike to get more exercise haha .I did some crazy off road riding bent my derailer and chain so I just use motor on my x .hard to find a chain for it .you need like 132 link chain .
 

Bubba zanetti

Active Member
Region
Canada
City
Trail, BC
This is a great thread and really convincing me this should be my first ebike. I’m checking out some Giant bikes tomorro, which are more money. Unless someone can update to the contrary, I’ll likely order the RX tomorrow.
 

Kevin8tor

Active Member
I have also noticed my range goes up in higher PAS levels, not sure why, and since I'm 98% in PAS1, I haven't investigated it further. I did an 18.2 mile ride in 36 degree weather (I'm 240 with gear) and came home with 70% battery riding in PAS1. I'm pretty impressed with the range, particularly in cold weather. I love my RX and can't find a fault with it. It's a workhorse.
 

AHicks

Well-Known Member
Region
USA
City
Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
I'm 315lbs and find 35 miles is easily attained, even when riding in the hilly area I ride in frequently (19ah battery). I'm most frequently in PAS 1 on the level sections, but I'll frequently go up to 2 and 3 for some of the bigger hills. I find using a higher PAS level far more battery friendly than using the throttle to climb. My only question when checking out an up coming hill of any consequence, is whether I should drop down a couple of gears to climb it, or continue in the gear I'm in! Shifting up or down while climbing, with the shift sensor in play, causes a big loss of momentum that's tough to get back until you get to the top. A PAS change is all electrical, with no loss of momentum. Works seamlessly, seems way more efficiently, and seems much more battery friendly.

That said, when riding in temps below about 40F, your battery is not working at peak. As it gets colder battery mileage is going to drop.