Better battery remaining accuracy on the 700

I got my 700 in mid June. After about 200 miles I decided to have my controller display the battery voltage rather than % remaining, since it was so inaccurate as a percentage left.

When fully charged it goes to 54.8 volts. I do not want to run the battery below 44 volts so I set my scale to drop 2.5 volts for the first three levels, then 2.1 volts for the last two levels. It seems to give me a pretty accurate usage and remaining charge. If you have problems getting the controller to accept a number higher than about 52 volts, save whatever level it will accept and exit the screen. Then go back in and try again - mine let me increase the maximum voltage number by 1 each time I repeated this.

I've been riding at the beach and had exactly 40 miles on my battery before I recharged it today. Keeping an eye on it as I rode I felt it was very consistent in reflecting the reduced voltage remaining in the battery. It was about 45.5 volts when I plugged in the charger. It is now back to 54.8 volts. I was mostly riding in pedal assist 5 or 6 of nine levels. 15-18 mph for the most part. Of course it is flat, and there was little breeze today.
 

cstoebe

New Member
Perhaps Ride1Up is suggesting to charge the battery less than 100% as I had read in one of his comments. I charge my batteries to 80% hoping to lengthen the battery life. Plus I live is AZ and the garage ac is set to 95 to keep the batteries cooler.

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tlippy

Active Member
Every manufacturer is suggesting 80% charge on every LiOn application. Do you try to keep your cell phones at 80% max? It's impossible. I intend to charge my 700's battery to 100% on every cycle. Batteries are good for 500 cycles no matter what % you charge them to. I will not let the battery
ON CHARGE much after it reaches 100%. I'm thinking there's too much concern about this 80% thing. I did ask R1U if A Luna charger, which has an 80% max cycle, is better than the O.E. charger. The reply was "use the O.E. charger. It's designed for our bikes". Good advice, IMHO. Just ride and charge.
 
tlippy, I am with you on the battery charging thing. Too much trouble trying to get it just right. I don't charge my mountain bike until the hours right before I next take it out, but I charge the R1U whenever it needs it, and take it to 100% even if I am not going to use it for a few days. Both bikes feel much peppier with a full charge vs. even an 80% charge. Plus, I want the R1U ready for whenever the mood hits me to ride or run errands.

cstoebe, thanks for the voltage vs percentage chart. I could probably run my battery down further than I do, but a 40 mile range seemed to be plenty.

The way I look at is that I can get 40 miles range from the battery and they are supposed to good for 500 charges (and still be usable after that), so that is 20,000 miles. I won't own the bike that long I am sure. All my riding is recreational. I've got 500 miles on the mtn bike in four months, and 300 on the R1U in three months, so I will be putting less than 2000 miles on either one in any year. That gives me 10 plus years of use unless the battery fails.
 

Bikeman

Member
I have found if I don’t charge my bike up to 100%, the cells get out of balance pretty quick. Not good for the battery and not good for the performance.

On my three cell electric RC airplanes, I get to see the voltages of each cell on my charger. If it takes three hours for my battery to charge, it’s a half hour to charge and 2 1/2 hours to balance.

If you do 80% I would only do that a few times and then go to 100 (green light on). You may find that your batteries gets so out of balance you can’t fix it.
 

Bikeman

Member
I got my 700 in mid June. After about 200 miles I decided to have my controller display the battery voltage rather than % remaining, since it was so inaccurate as a percentage left.

When fully charged it goes to 54.8 volts. I do not want to run the battery below 44 volts so I set my scale to drop 2.5 volts for the first three levels, then 2.1 volts for the last two levels. It seems to give me a pretty accurate usage and remaining charge. If you have problems getting the controller to accept a number higher than about 52 volts, save whatever level it will accept and exit the screen. Then go back in and try again - mine let me increase the maximum voltage number by 1 each time I repeated this.

I've been riding at the beach and had exactly 40 miles on my battery before I recharged it today. Keeping an eye on it as I rode I felt it was very consistent in reflecting the reduced voltage remaining in the battery. It was about 45.5 volts when I plugged in the charger. It is now back to 54.8 volts. I was mostly riding in pedal assist 5 or 6 of nine levels. 15-18 mph for the most part. Of course it is flat, and there was little breeze today.

Wow! You did good getting 40 miles down to 44V. Kevin suggested 41.5 so you did super good. I get about 30 miles per charge and I go down to 42V.

Your post title is, “Better battery remaining accuracy on the 700.” If your battery remaining is not accurate, why not adjust it to where it is accurate? It’s your choice whether you want volts or percentage, but if your percentage was off just adjust it so it’s on.
 
I experimented with battery voltage to see if it might be more accurate. Now I am fairly used to it, plus I have an idea of far I can really go. At this point I will probably leave it the way it is. Seems like it would be more trouble than possible gain to go back to voltage, and these days I am all about taking the easy way out. :)

The first six weeks of ownership I tweaked lots of things to get it just right; now I just hop on it and ride. The only long rides I take will be when I take it to FL, and those probably won't go beyond 25 miles per ride. The last thing I want to tweak is the chain line. One of the posts on here showed a picture of what they did to move the chain ring inwards. It is essentially what I tried to do 6-8 weeks ago, but with much more success than I achieved. I did not find the right bolts (ironically, the only store that I went to for replacement bolts was Ace Hardware), but I will look elsewhere to find what I need to fix it. My chain does not fall off the chain ring, but it will move to an incorrect gear in the back if I back pedal.
 

tlippy

Active Member
I got my 700 in mid June. After about 200 miles I decided to have my controller display the battery voltage rather than % remaining, since it was so inaccurate as a percentage left.

When fully charged it goes to 54.8 volts. I do not want to run the battery below 44 volts so I set my scale to drop 2.5 volts for the first three levels, then 2.1 volts for the last two levels. It seems to give me a pretty accurate usage and remaining charge. If you have problems getting the controller to accept a number higher than about 52 volts, save whatever level it will accept and exit the screen. Then go back in and try again - mine let me increase the maximum voltage number by 1 each time I repeated this.

I've been riding at the beach and had exactly 40 miles on my battery before I recharged it today. Keeping an eye on it as I rode I felt it was very consistent in reflecting the reduced voltage remaining in the battery. It was about 45.5 volts when I plugged in the charger. It is now back to 54.8 volts. I was mostly riding in pedal assist 5 or 6 of nine levels. 15-18 mph for the most part. Of course it is flat, and there was little breeze today.
There is a new YouTube video posted by Kevin on Sep Explains in detail how to set-up and use the KD-218 controller. A must watch for everyone.