new owner and question about our bike display of battery power left

GET

New Member
Bought my wife and I radcity ebikes for Christmas. Have had them about 3 weeks, first want to say that they were easy to assemble, the only issue was both bikes had bent derailleur guards, seems to be common, I took them off and bent them out and put them back. Every thing is working great, we have had several rides. We live in the middle of Kansas and have been lucky with temps in the 40's and 50's rather then much colder as it usually is this time of year. I am 71 and the wife is 68 and even with the Kansas wind today we had fun on a 15 mile ride so I know we will use these a lot. Now the concern. Everything on the display works great except the indicator of battery power left does not change. It shows we have full power levels but when I take the batteries off and check with the gauge on the battery, it shows one mark red on the indicator, which is what I would expect for the distance ridden. We try not to go over pedal assist 1 or 2 because we want to have the exercise. Why is the indicator on the LCD display not showing the battery use? Is there a setting I am not aware of? I have emailed Rad power, they asked for a video which I sent, but because of the holidays I have not heard back.
 

AHicks

Well-Known Member
Myself, I wouldn't put a lot of weight on any disparity between one gauge vs. another. If you really want to know what's going on, wait until the bike's display drops one bar (15 miles or so?) and put the multi meter on it to see what it says. Then do the same when it drops the second bar. With that info, you have something useful regarding when it's time to charge and what your useful range is.
 

mrgold35

Well-Known Member
I have two 2016 Radrovers and 2019 Radcity Step-thur. I've noticed the LCD battery indicator is doing double-duty:

- When stationary, it shows the battery current power in 20% blocks. Won't dip down to the next block until +21% is depleted.
- When riding, shows how much power is utilized when using PAS/throttle. It can dip down 1-2-3 bars when the Rad bike needs max power; but, back up the same amount when stationary at a stop light a few minutes later.

At PAS 1-2 on the Radcity, you are probably looking at +45 mile range depending on terrain/wind/speed and the amount of weight each ebike is pushing. There is a good chance you haven't dropped below the 20% mark on the LCD screen on your 15 mile ride at PAS 1-2? I can go a little under 40 miles on my 11.4ah 2016 Radrover at PAS 2 on level ground (8 -13 mph); but, down to 22-26 miles at PAS 3 (17-20 mph). When my wife (130lbs) and I (300lbs) would ride together with the Radrovers over 30 miles, I would switch battery packs a little over 1/2 into our ride. She would still be at 60%-80% power; while, I was 40%-60% at the 1/2 point.

I think the battery packs have a red battery power level for the lowest charge? Been a while since I've checked my battery power level from the older and newer battery packs.

One thing I did (once I got into ebike riding shape) was take the other Radrover spare battery and took a maxed out ebike ride. I wanted to see how far I could go until I got below 10% battery power with the blinking battery indicator on the LCD screen. Sometimes it is hard to tell how much power you have with the LCD screen power level going up/down with PAS/Throttle. I've got caught once riding home from work commuting and ran out of power a mile away (+90 degrees, uphill, and stiff +15 mph headwind). It is easier to push the ebike compared to pedaling in those conditions.
 

BlueGenes

New Member
Based on my experience with my 2018 Rad City, the gauges on both the battery and the display are very inaccurate. Like you, my battery always says I have far less juice than the display. I've learned, through trial and error, how many miles I can roughly get out of the battery. I rely mainly on the odometer to gauge how many miles I have left. Unfortunately, my battery is close to death (after 3500 miles rode mostly at PAS 2). I currently get just 10-12 miles from a full battery. More than once I've had to push or pedal the bike several miles home after the battery has been depleted. I can assure you, pedaling these bikes without any power is not fun at all.
 

smorgasbord

Active Member
I have two 2016 Radrovers and 2019 Radcity Step-thur. I've noticed the LCD battery indicator is doing double-duty
That's not what's happening. The gauge is really just a crude measure of voltage across the battery terminals. When you're riding and pulling power, voltage will drop - hence the battery charge will appear lower than it really is. I'd wait a few minutes after stopping to assess what the gauge is saying about the battery. The built-in battery bars are probably even more crude than what is built into the display, although the RadPower displays are pretty low-end and only show 5 bars instead of a percentage.

Here are charts showing battery percentage as a function of voltage. One for 48V and one for 52V. I think these have been posted here before....

48 Volt Percentage Chart

52 Volt Percentage Chart

In general, you don't want to go below 20% and some systems will stop you sooner.
 

mrgold35

Well-Known Member
I don't ride the wife's new Radcity with the newer 14 ah battery (ebike is too small for me); but, I've noticed I don't feel any drop in power delivery with my older 11.4ah Radrovers as battery power levels drop from 100%-20%. Maybe, the drop isn't enough for me to feel with the old butt dyno and the LCD voltage display number stays at the PAS selected level. It is not until I get to the 1 bar mark at PAS 3 is where I feel and see the drop in power with butt dyno and the voltage display number in the LCD (usually slow down and drop to PAS 2 for max power at that level).

Looks like the Radrover and battery is designed to always deliver max 48v power until it physically can't (no slowly ramping down the voltage as power is depleted).
 

KenS

Member
I would not worry. I have a short commute but with significant hills such that I am often in PAS 3 or 4. It took several days before I lost a bar on the indicator.
 

AHicks

Well-Known Member
I don't ride the wife's new Radcity with the newer 14 ah battery (ebike is too small for me); but, I've noticed I don't feel any drop in power delivery with my older 11.4ah Radrovers as battery power levels drop from 100%-20%. Maybe, the drop isn't enough for me to feel with the old butt dyno and the LCD voltage display number stays at the PAS selected level. It is not until I get to the 1 bar mark at PAS 3 is where I feel and see the drop in power with butt dyno and the voltage display number in the LCD (usually slow down and drop to PAS 2 for max power at that level).

Looks like the Radrover and battery is designed to always deliver max 48v power until it physically can't (no slowly ramping down the voltage as power is depleted).
Big (300lb) rider here too. My own impression, after riding an '18 City with the OEM stock 750w(?) DD motor, a1500w aftermarket DD motor, and currently with a MAC 12t geared hub motor (my favorite by far), I notice a performance degradation starting when the battery (an OEM RAD battery) gets down to maybe 50 volts. It's nothing huge, but it is noticeable. Bike feels extra peppy with a full charge (fun!), then settles into a routine, and when voltage drops down to about 47v (50% charge) it's asking for noticeably higher power settings to cover the same country (the doldrums). This is the point where I'll finish up my ride and get it on the charger. Noteworthy is that the bike will make 35 miles easily with the current gear driven motor, few of my rides even go 15 miles. 3-10 miles would be average. Point being, the bike is generally only charged about once a week - when the voltage has dropped to 46-47v.
 

mrgold35

Well-Known Member
Big (300lb) rider here too. My own impression, after riding an '18 City with the OEM stock 750w(?) DD motor, a1500w aftermarket DD motor, and currently with a MAC 12t geared hub motor (my favorite by far), I notice a performance degradation starting when the battery (an OEM RAD battery) gets down to maybe 50 volts. It's nothing huge, but it is noticeable. Bike feels extra peppy with a full charge (fun!), then settles into a routine, and when voltage drops down to about 47v (50% charge) it's asking for noticeably higher power settings to cover the same country (the doldrums). This is the point where I'll finish up my ride and get it on the charger. Noteworthy is that the bike will make 35 miles easily with the current gear driven motor, few of my rides even go 15 miles. 3-10 miles would be average. Point being, the bike is generally only charged about once a week - when the voltage has dropped to 46-47v.
I can be up to 330-340 lbs in winter bike commuting with layered cold weather gear, commuter back pack, bar mitts, lunch/water, work clothes, fix a flat tools/tube, etc...

Does the pre-set wattage per PAS level on the LCD screen also drop when the battery gets below 50% charge? The wattage per PAS stays the same for my 16 rover until I start to get below 20% charge in PAS 3 when the rover can't do the full PAS 550 watts or 750 watts with throttle.
 

KenS

Member
I can be up to 330-340 lbs in winter bike commuting with layered cold weather gear, commuter back pack, bar mitts, lunch/water, work clothes, fix a flat tools/tube, etc...
Color me impressed, at getting out at this time of the year. It is 34 F here currently, but there is a 25-30 mph wind. The big issue for me are the wind speeds.
 

mrgold35

Well-Known Member
Color me impressed, at getting out at this time of the year. It is 34 F here currently, but there is a 25-30 mph wind. The big issue for me are the wind speeds.
Wind and wet/icy roads are my limits. Anything over 20 mph headwind with gust +25 mph results in my range being reduces by 25%-40%. That is why I leave a battery charger at work because I ran out of juice "once" a mile from home on my 15 mile round-trip commute on a +20 mph headwind day.
 

AHicks

Well-Known Member
I can be up to 330-340 lbs in winter bike commuting with layered cold weather gear, commuter back pack, bar mitts, lunch/water, work clothes, fix a flat tools/tube, etc...

Does the pre-set wattage per PAS level on the LCD screen also drop when the battery gets below 50% charge? The wattage per PAS stays the same for my 16 rover until I start to get below 20% charge in PAS 3 when the rover can't do the full PAS 550 watts or 750 watts with throttle.
There's very likely large differences in a lot of the specifics between the '16 system you're on and the one I'm using - which is very similar to Boltons' performance kit for the Rad.

I believe they are both dropping available wattage as the battery voltage drops (no regulator in play). It's just that it's dropping so little at first I don't notice it anyway. This is pretty typical for Lithium based battery performance (even when flying them in RC). It's not until they drop below a certain point where the controller may go into a "limp" mode, and you had better be close to home when that happens as voltage much below that point is going to shut it down. This is one of the reasons I like to charge at 46-47v. -Al
 

BikeHelmet

New Member
2019 Rad Rover here - with a < 150lb rider, hilly environment, I went about 30km (18.6miles) without losing a single bar, mostly PAS 1 and 2. Those bars do just reflect "Over 80%, over 60%, over 40%, over 20%, over 0%", etc.

I use the throttle occasionally to get started on hills and stuff, or will throttle when my legs need a break.

It makes sense that someone that weighs twice as much would use significantly more energy. I imagine if you're light, athletic and keep it on PAS 1, 100+ mile ranges are possible on a new battery pack. Don't forget your accessories though - LED headlights and whatnot consume power too.
 

AHicks

Well-Known Member
I don't know about 100 miles, but there's darn sure going to be a wide variety of responses when asked how far people can go on an avaerage charge. Weight is one piece obviously, but tire inflation could be another, especially on a fatty (fat tire, not rider!). Then there's the difference in riding styles, and a big piece of that is going to depend on the rider's experience level. For instance, my average charge mileage nearly doubled from my first charge to now after riding a couple thousand miles. Efficiency gained through proper use of PAS level and being in the right gear is a really big deal. We can also add to this picture with the rider's reason for being on a bike. Are we running errands? Commuting? Or riding because it's a nice day out?