The "UNOFFICIAL" Hydra FAQ thread....

What is everyone's experience with battery performance? Do you get consistent power down to low battery %? I have been tracking % on the bluetooth app and after 50% power seems to drop off quite noticeably. Yesterday, I got about 18-20 miles on city streets in level 1-3 (mainly 1 and 2). I had 35% power left at the end of the ride but it felt like it was in limp home mode.
I have not had this problem. I get consistent power/ battery performance at below 50%. I haven't taken my battery less than 20% though, so I can't speak for below 20%. I have a CrossTour with 2300w motor with Archon controller.
 

bexamous

Active Member
Region
USA
I'm bit confused about battery life. I went for ride today. I set charger to 80% setting so it cuts off at ~55v (I forget if cutoff is 55.0v or 55.4v). I then turn on ebike and display, with battery known to be at ~55v, reports 70%. I then go ride.. I'm trying to judge when to turn around using display's reported percentage. When it gets ~40% I figure I should turn around and have a little buffer left over when I arrive at home. On way home display gets down to 15% and bike turns off, I turn it back on and it says on for a minute and goes back off and I ride last mile without power. I get home and check and battery is at 48.6v.

So for display 70%->15% was entire battery? That doesn't seem right... also these percentages are annoying as I feel like it adds some guessing as to wtf is going on. Percentage also seems like they're mostly based off battery voltage? I noticed after going up a 1/2 mile 20% grade the display's battery percentage started going up. I'm sure voltage was sagging under load of climb, but it has a current meter, can't we set pack's aH and not rely on voltage so much? Whatever, I may just change display to show voltage. Least volage satting under load mades sense, capacity percentage sagging under load odesn't make sense. ;)

Anyways so really pack went from ~55v (~3.92v/cell) to 48.6v (~3.47v/cell). Why is it turning off at 3.5v/cell, 3.0v/cell is more reasonable cutoff?

Also man makes me wish Hydra had more like a 1200wH battery, lol, I only did like 23 miles total. I guess really doing ~3.92v->~3.47v I really only used like 400wH or something. Also I think I can also get better wH/mile with better programming. This is my first ebike and in my mind I figure if I could put out 200watts on avg and bike did an extra 100watts on avg.. like great. But I feel like in practice I'm putting out 100watts and bike is doing 200watts. And if I try to put out 200watts bike is putting out 500watts, lol. I dunno. I know much of my ride I was barely breaking a sweat because bike was doing too much work, and I'm in like eco1.
 
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bexamous

Active Member
Region
USA
Err and on the display, the stock DP C18.UART, in the information tabs, all the battery info not set. Is it supposed to be able to get info from BMS?
 

BarnBoy

Well-Known Member
Region
USA
City
Pleasanton, CA
Couple of answers to the above…

@bexamous - the manual and YouTube videos for the DP C18.uart state it currently doesn’t use that battery data. If interested in battery, get the XiaoXiangBMS app. Here is what it looks like…

16DF9834-62B7-4EF1-A9DB-B4CB75B71586.jpeg



The manual also says to use the Voltage setting over percentage. I agree and have the 14s charts committed to memory (turn back point is 48V)….
-BB
 

bexamous

Active Member
Region
USA
Hmm have Android phone. Tried getting XiaoXiangBMS app from playstore, it seems to be missing lots of features. Had to try a couple versions, someone linked this one which I think is copy I used in end: http://www.jiabaida.com/xiaoxiang.apk

But now I'm more confused why bike turned off when display was reading 15% and pack voltage measured 48.6v. 48.6/14=3.47v which made me think LVC was at 3.5v/cell. But using BMS app that is not the case. Doesn't seem to be any reason for it to have turned off when pack was only at 48.6v.

Charging now though I am seeing 13 cells are all ~4.102+-0.003 and 1 cell hits 4.200 and charging stops. They then all drop a little when charging stops, screenshot is after sitting for a minute or two. From past experience with RC lipos this is what a bad cell usually looks like.. it'll have higher IR and reads high under charging and sags a ton when discharging. I'll try to run pack down again today and see what individual cell voltages are when pack is at 48.6v. Hopefully that one cell isn't falling to 3.0v way early.

Oh also funny.. while charging the charger is reporting 1.8amps, the battery is reporting 2.3amps. I put a clamp meter on and it reads 2.05amps. I hate when nothing agrees, lol.

Oh also interesting, this charger must be noisey as crap. I use powerline networking adapater for one room in our house. When charging bike's battery the powerline networking stops working. No other devices have affected it. It doesn't get slower, it effectively stops working.. pinging local ip has >50% packet loss and packets that do get through ping reports 1-3 full seconds, lol.
 

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blueskyca

Member
Region
USA
City
SoCal
Hmm have Android phone. Tried getting XiaoXiangBMS app from playstore, it seems to be missing lots of features. Had to try a couple versions, someone linked this one which I think is copy I used in end: http://www.jiabaida.com/xiaoxiang.apk

But now I'm more confused why bike turned off when display was reading 15% and pack voltage measured 48.6v. 48.6/14=3.47v which made me think LVC was at 3.5v/cell. But using BMS app that is not the case. Doesn't seem to be any reason for it to have turned off when pack was only at 48.6v.

Charging now though I am seeing 13 cells are all ~4.102+-0.003 and 1 cell hits 4.200 and charging stops. They then all drop a little when charging stops, screenshot is after sitting for a minute or two. From past experience with RC lipos this is what a bad cell usually looks like.. it'll have higher IR and reads high under charging and sags a ton when discharging. I'll try to run pack down again today and see what individual cell voltages are when pack is at 48.6v. Hopefully that one cell isn't falling to 3.0v way early.

Oh also funny.. while charging the charger is reporting 1.8amps, the battery is reporting 2.3amps. I put a clamp meter on and it reads 2.05amps. I hate when nothing agrees, lol.

Oh also interesting, this charger must be noisey as crap. I use powerline networking adapater for one room in our house. When charging bike's battery the powerline networking stops working. No other devices have affected it. It doesn't get slower, it effectively stops working.. pinging local ip has >50% packet loss and packets that do get through ping reports 1-3 full seconds, lol.
Check your cell voltages when it shuts off and see if the high cell during charging is also the low cell during discharge. I've had bad cells appear after many discharge cycles and that's how they behave. Your pack appears to be fairly new.
 

WaxedWookie

Active Member
Region
Australia
Hmm have Android phone. Tried getting XiaoXiangBMS app from playstore, it seems to be missing lots of features. Had to try a couple versions, someone linked this one which I think is copy I used in end: http://www.jiabaida.com/xiaoxiang.apk
Thanks for the link!

A quick note to those trying it - for me, it downloaded as xiaoxiang.zip - if this happens to you, you'll need to rename it to xiaoxiang.apk to install it. You may also need to enable external sources (or similar) in your permissions to install non-play store apps.
 

Csubi

Active Member
Region
Canada
Ya, my bad. I downloaded it to my Android phone. It downloads as a .zip file. You need to select the file (which goes to the Downloads folder) and rename it to .apk (from .zip)
Then you can install it. It opens fine. I do not have my bike yet, so I cannot use it. It did find my Bluetooth Sous-vide machine and wanted to connect to that so looks dialed in!
 

Merle Nelson

Well-Known Member
Region
USA
Ya, my bad. I downloaded it to my Android phone. It downloads as a .zip file. You need to select the file (which goes to the Downloads folder) and rename it to .apk (from .zip)
Then you can install it. It opens fine. I do not have my bike yet, so I cannot use it. It did find my Bluetooth Sous-vide machine and wanted to connect to that so looks dialed in!
Fantastic info. Maybe I will be able to change settings on my Hydra with a newer phone I have then instead of having to buy a PC laptop.