Range on ToughRoad

[Saratoga Dave]

“… When what to my wondering eyes should appear
But three zeros on the range indicator and a half mile hill in front of me”

Well, I should know better. I’m on record here a couple of times about the Yamaha system on my Giant. As much as I love it, and I do, when it says 20% battery remaining, what it means is, Find A Plug. Today I did a nice 50 miler in preparation for a cancer ride next weekend, and in so doing, discovered that when the battery indicator rolled from 9 to 8 percent left, the range number went instantly from eight miles to 000 and the assist went into full Turtle mode… barely there at all. With still four miles to go and that fine hill.

And that span from 20% down to 10 was absurd. Really, that whole second 50% of the battery is absurd on this thing. If the scenery doesn’t grab you, you can just watch the battery and the range vanish before your eyes while you wonder why the hell you didn’t bring the charger, knowing this was a 50 miler.

Oh well, it was a nice hot day, tons of sun, and I answered the question of is it reasonable to expect to complete this ride - which will not be casual, but pretty energetic, with some decent elevation - on a single battery. Have to get going on Plan B!

 

[Catalyzt]

Ah, bummer! I appreciate your post, because I've complained about Shimano's range estimates as well. It literally gives me an estimate of 92 miles at the start of a ride, it drops into the low 50s after 4.5 miles after climbing an 850 foot hill, but 5 miles later, after descending the back of the same hill, will show me a range of 104-107 miles-- more than I had when I started. I know that's normal, but it still is crazymaking for someone like me who's a bit OCD.

However, it has not stranded me the way you describe. It may go from 12 miles to 4 over the course of a single mile, but that's if I'm climbing... and it won't go into "Turtle Mode" (e.g. reserve = mandatory ECO) until HIGH, NORM and ECO are all reading zero. If it tells me I got 0 for HIGH, 1 for NORM and 3 for ECO, it will still let me have 100 feet of HIGH if I need to climb the last hill to my house.

Oh, and one other little bummer: I think my motor might be set up for 29 inch wheels, which means it's cutting out 5% sooner than it should, speed reads 5% faster, and distance is 5% faster than Google Maps. That's not a range issue... I know it's a PITA to fix, not even sure the dealer can do it, I think the dealer can check it, but Shimano would have to change it. So I have to mentally adjust Shimano miles to Google Map or Strava miles.

So I will stop complaining! What experience has taught me is that my range is 40 miles with 4,000 feet of vertical. When I total around 5,000 feet, I can barely crack 30 miles.

On flat terrain, I could probably ride to Mars. But I'll never know, because there's no flat terrain where I live.

Also, Shimano is good in that I don't have much power reduction at all towards the end of the battery; with my front-hub-drive kit bike, the power drop is really pronounced for the last 1.5 miles.

All I can recommend is calculate your vertical and range very carefully and make notes. For longer rides, I trust my notes, not the indicated range, which can be harrowing if I've done a 2,000 foot climb, I'm 12 miles from home and the range indicator says I only have 10 miles left. But the math doesn't lie-- after I go down that hill, I'm back up to 30 miles of range, and I get home with power to spare. I also leave at least 10% reserve for wind, atypical climbs that drain battery faster (I think going up moderate grades really fast drains the battery quicker than slow climbs up steep ones) or other variables, like just being more tired than I realized.

And... I'd better start checking battery health, too. Next summer, it probably won't do quite as well.

 

[conix67]

I'll throw away any "range" estimate the bike provides. It just doesn't know what's coming so the estimate would be highly inaccurate anyway. However, % of battery capacity remaining is something I could make use of and the bike can provide reasonably accurate number for this. On my Roam E+ with fresh battery, it does provide reasonably accurate numbers based on my experience, but expecting completely linear scale down to 0% may not work. I've gone down below 10% few times but I'd do that only if I'm already close to the destination.

 

[st0ut]

My rule is if the total distance is over 30 miles put the charger in the pannier.

 

[Saratoga Dave]

Not a bad rule.

 

[RabH]

“… When what to my wondering eyes should appear
But three zeros on the range indicator and a half mile hill in front of me”

Well, I should know better. I’m on record here a couple of times about the Yamaha system on my Giant. As much as I love it, and I do, when it says 20% battery remaining, what it means is, Find A Plug. Today I did a nice 50 miler in preparation for a cancer ride next weekend, and in so doing, discovered that when the battery indicator rolled from 9 to 8 percent left, the range number went instantly from eight miles to 000 and the assist went into full Turtle mode… barely there at all. With still four miles to go and that fine hill.

And that span from 20% down to 10 was absurd. Really, that whole second 50% of the battery is absurd on this thing. If the scenery doesn’t grab you, you can just watch the battery and the range vanish before your eyes while you wonder why the hell you didn’t bring the charger, knowing this was a 50 miler.

Oh well, it was a nice hot day, tons of sun, and I answered the question of is it reasonable to expect to complete this ride - which will not be casual, but pretty energetic, with some decent elevation - on a single battery. Have to get going on Plan B!

I feel your pain Dave, I noticed this right from the start on my Giant Road E+1 Pro! It just drops like a stone as soon as it reaches 20%, I just treat 20% as zero now and make sure I have enough left for my final climbs if I'm only carrying one battery! The experts do say its best not to go below 20% for battery longevity!

 

[DaveMatthews]

Sounds like the old 80/20 rule... except there's only really 80...