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[DanielCoffey]

Under normal circumstances, how much does the DigiNow charger slow down as it approaches the end of a charge?

The situation is that I have a single 3.3kW unit with the v2.5 controller and I am one of the unfortunate folks with a faulty unit who are awaiting a replacement controller under warranty.

One of the faults with my controller is that it does not taper the charge as the target voltage is approached so if I set it to 3300W, it maintains that power output all the way till the cutoff voltage is reached then stops. The voltage lift caused by the high charging current means that once charging is terminated (at 116.4V) the pack voltage sags back down nearly a couple of volts (115.0V) and ends up with about 95% SOC and correspondingly reduced max range.

If I use the bluetooth app to set a slower charge rate, the voltage lift is lower so I can get closer to the desired voltage but I have to do this manually each time. It takes a slow charge of 800W to actually charge the pack to the point to where 100% SOC is displayed on the dash once charging stops. Even then there is still a bit of voltage lift.

I was wondering how low a charge rate it was supposed to deliver at the end of the charge cycle?

Ordinarily I would not mind only charging to 95% but I do have an appointment coming up soon where I will want to leave with a completely full charge so I will have to juggle it manually while I wait for a replacement controller.

Out of interest, does anyone know how slowly the stock charger used to go at the end of charge?

[flattetyre]

What kind of charger DOESN'T have CV phase? That's just ghetto.

[DanielCoffey]

As I said, I have a known defective controller and this is unexpected behaviour. I am just needing advice on how to achieve a 100% charge manually as though the charger was operating normally.

Once Brandon has received supplies of working v3.0 controllers I am on the list to receive one.

[BrianTRice@gmail.com]

The DigiNow controller does have a CV phase.

I am also waiting on a v3.0 controller, as my v2.5 controller appears to have developed a dead transmit line/wire. I've been commuting on v2 for the last two months.

For DigiNow 2.5, the ramp rate setting (documented by me at the unofficial manual) determines how the CV phase proceeds.

[DanielCoffey]

It is the end of charge ramp I need to know more about. I know the initial ramp is 50W per tick but I don't know how much it slows at the tail end.

[DanielCoffey]

From looking at the manual, this is the condition that is not working on my single v2.5 unit...

"Reaction/Reduction Conditions: When reported bus voltage from any BMS >= V, the broadcast power setting ramps down at the normal ramp rate (delta P) until voltage < V"

At least I can tell how it *should* behave from this, so thanks. It is a shame my unit doesn't but it does look like it is supposed to step lower and lower until the ramp goes right down to 0W then charging stops. The last few seconds would be as low as 50W power.

Here is the output of my log showing the last few "ticks" of a charge cycle. The settings were "1164,57,1,3300,0,50"

0111 13:56:55 1164,1162,0,283,26,0,57,0,57,26,27,0,0,1,3300,3300,0,50,3
0116 13:56:57 1164,1162,0,283,27,0,57,0,57,26,27,0,0,1,3300,3300,0,50,3
0120 13:56:58 1164,1162,0,283,27,0,57,0,57,26,27,0,0,1,3300,3300,0,50,3
0124 13:56:59 1164,1164,0,283,27,0,57,0,57,26,27,0,0,1,3300,3300,0,50,3
0128 13:57:00 1165,1165,0,0,26,0,57,0,57,26,27,0,0,1,0,3300,0,50,3
0133 13:57:02 1165,1155,0,0,0,0,57,0,57,26,27,0,0,1,0,3300,0,50,3
0137 13:57:03 1165,1154,0,0,0,0,57,0,57,26,27,0,0,1,0,3300,0,50,3
0141 13:57:04 1165,1154,0,0,0,0,57,0,57,26,27,0,0,1,0,3300,0,50,3

I will create a manual profile at, say, 200W to trickle it to pretty close to 100% for the last part of a charge when I really need the full range.

[BrianTRice@gmail.com]

That's definitely not what the controller does normally, by my observations.

DigiNow may make claims one way or the other; since I don't have anything in writing from them, I rely on corroborated hearsay.

The manual profile is probably a good choice, but you could try up to 500W and most likely get a good result.

[Richard230]

I have connected my 2018 S Zero charger to a Kill A Watt meter and the closer it gets to a 100% charge the higher the amperage pull from my 120V wall socket - topping out at 12 amps.  Interestingly, when the charger finally decides to cut off it does so immediately, without any tapering off. Once that happens, the power draw drops to 4 or 5 watts and will stay there until you disconnect the charger cord.  I have no idea how the cells in the pack are balanced, but apparently it happens somehow as the Zero app typically shows a differential of 4 or 5 mV when the pack is fully charged.   

[BrianTRice@gmail.com]

I have connected my 2018 S Zero charger to a Kill A Watt meter and the closer it gets to a 100% charge the higher the amperage pull from my 120V wall socket - topping out at 12 amps.  Interestingly, when the charger finally decides to cut off it does so immediately, without any tapering off. Once that happens, the power draw drops to 4 or 5 watts and will stay there until you disconnect the charger cord.  I have no idea how the cells in the pack are balanced, but apparently it happens somehow as the Zero app typically shows a differential of 4 or 5 mV when the pack is fully charged.   

The BMS performs cell balancing using its own circuit, under the conditions when there is a charger attached and (IIUC) the incoming current is below a certain value which is less than the onboard charger's typical rate of 1200W = 11A DC. When it performs balancing, it is directing the charging current in bursts to specific layers of the cell stack (all cells connected in parallel between position 1 and 28).

[talon]

Daniel,

I have the V2.5 "dev kit" charge control unit and mine does the same thing--sort of. I cannot say it is or isn't working as intended as I do not know how Brandon intended it to work, but I will offer this:

There is a certain method to charging to rebalance the cells and approach 100% at the same time and Brandon has said he follows Zero's way of doing this. What I notice my charger doing is only sometimes tapering down between 0-1000W at high SoC's, regardless of what my target wattage is set to (this might depend on how many units I have plugged in). Sometimes when charging it does not taper at all and this might have to do with a glitch or that balance/slowly approach 100% condition. I have been told by others in the "dev group" that not all years (and possibly individual within the same model year) Zero bms's react the same when topping off. I have noticed my displayed voltage while charging has lifted above 116.4V at higher power levels, but always rests down to a non-overcharged voltage if stopped. Some BMS's do not tolerate this and will close the contactor early. My BMS has done it occasionally leaving me at a rested voltage of 115.4-115.9V. I don't see it as a big deal really, as long as I don't come back with it below 115V. Usually the tapering presents itself as the diginow setting wattage back to 0 and re-ramping up until the voltage again passes some parameter. This is just how MY unit operates so your results may vary.

Another possibility that makes it very difficult to know exactly how these work is that by the time I approach full, the chargers may be hitting thermal cutback anyway. When operated at full power it can only take 20 minutes on a hot day for them to throttle back (a little) to protect themselves, and that is installed off the bike in the shade with the large heatsinks and fans!

Oh and my bike may have "abnormally high impedance" as presented only in temperature increase while charging. I'm still putting all the data together.

[DanielCoffey]

Hmm... I wonder if it is the bikes BMS cutting off the charge then? If you note the line in the log where the charge ends, it briefly reaches 116.5V and perhaps the BMS cuts off instead of allowing the DigiNow to ramp down the current.

The charger is being consistent in this behaviour (apart from a second separate fault where it sometimes fails to start a charge). Regardless of the starting SOC or the charge rate I set in the app, the second the voltage lifts above the specified target, the charge stops with no ramp down at all. I have a 3300W profile, a 1300W profile and an 800W profile at the moment and on all three it approaches 1164 at full speed, tips over to 1165 and immediately stops with no ramp down.

What I will do is set up, say, a 1162 target voltage and see if the behaviour is exactly the same. It will either climb to 1163 and stop or climb to 1163 and ramp down properly. I'll report back.

Oh, and the bike is a 2018 DS 7.2 11kW.

[DanielCoffey]

Well, well. Talon you were right. The BMS on MY bike is interfering with the DigiNow... BUT I have still found a fault with my specific v2.5 controller. Here is what is happening...

Case 1 : 1164,57,1,3300,0,50

The charge session starts and ramps up at +50W per tick. Charge rate remains steady at 3300W until 1164 is shown on both DigiNow and BMS voltages. Voltage ticks up one more to 1165 on both DigiNow and BMS. Charge session is terminated and power falls instantly to 0W. DigiNow voltage stays at 1165 but BMS voltage sags back to around 1150. See log in earlier post.

I suspect the bike's BMS is triggering a shutdown once 116.5V is reported.


Case 2 : 1162,57,1,3300,0,50

This has highlighted some odd behaviour on my specific controller. Charge session starts and ramps up as expected. Charge rate remains steady at 3300W until 1162 is shown on DigiNow and BMS. Voltage climbs one more to 1163 and DigiNow starts ramping down at -100W per tick (apart from first tick) but it appears the DigiNow voltage has latched to 1163. The BMS correctly reports the sagging voltage as the charge rate tails off but the DigiNow does not sag and does not realise it can continue to charge. It tails off evenly to zero and terminates the charge.

Here is the tail of that log...

1161,1161,0,284,21,0,57,0,57,14,15,0,0,1,3300,3300,0,50,3
1161,1161,0,284,22,0,57,0,57,14,15,0,0,1,3300,3300,0,50,3
1161,1161,0,284,22,0,57,0,57,14,15,0,0,1,3300,3300,0,50,3
1162,1162,0,283,23,0,57,0,57,14,15,0,0,1,3300,3300,0,50,3
1163,1163,0,270,23,0,57,0,57,14,15,0,0,1,3150,3300,0,50,3
1163,1162,0,262,24,0,57,0,57,14,15,0,0,1,3050,3300,0,50,3
1163,1163,0,253,24,0,57,0,57,14,15,0,0,1,2950,3300,0,50,3
1163,1163,0,245,24,0,57,0,57,14,15,0,0,1,2850,3300,0,50,3
1163,1163,0,236,23,0,57,0,57,14,15,0,0,1,2750,3300,0,50,3
1163,1163,0,227,22,0,57,0,57,14,15,0,0,1,2650,3300,0,50,3
1163,1162,0,219,21,0,57,0,57,14,15,0,0,1,2550,3300,0,50,3
1163,1162,0,210,20,0,57,0,57,14,15,0,0,1,2450,3300,0,50,3
1163,1163,0,202,19,0,57,0,57,14,15,0,0,1,2350,3300,0,50,3
1163,1161,0,193,18,0,57,0,57,14,15,0,0,1,2250,3300,0,50,3
1163,1160,0,184,17,0,57,0,57,14,15,0,0,1,2150,3300,0,50,3
1163,1160,0,176,17,0,57,0,57,14,15,0,0,1,2050,3300,0,50,3
1163,1159,0,167,16,0,57,0,57,14,15,0,0,1,1950,3300,0,50,3
1163,1159,0,159,16,0,57,0,57,14,15,0,0,1,1850,3300,0,50,3
1163,1159,0,150,15,0,57,0,57,14,15,0,0,1,1750,3300,0,50,3
1163,1158,0,141,14,0,57,0,57,14,15,0,0,1,1650,3300,0,50,3
1163,1159,0,133,12,0,57,0,57,14,15,0,0,1,1550,3300,0,50,3
1163,1159,0,124,12,0,57,0,57,14,15,0,0,1,1450,3300,0,50,3
1163,1157,0,116,11,0,57,0,57,14,15,0,0,1,1350,3300,0,50,3
1163,1156,0,107,10,0,57,0,57,14,15,0,0,1,1250,3300,0,50,3
1163,1155,0,98,9,0,57,0,57,14,15,0,0,1,1150,3300,0,50,3
1163,1155,0,90,8,0,57,0,57,14,15,0,0,1,1050,3300,0,50,3
1163,1154,0,81,8,0,57,0,57,14,15,0,0,1,950,3300,0,50,3
1163,1154,0,73,7,0,57,0,57,14,15,0,0,1,850,3300,0,50,3
1163,1155,0,64,6,0,57,0,57,14,15,0,0,1,750,3300,0,50,3
1163,1154,0,55,5,0,57,0,57,14,15,0,0,1,650,3300,0,50,3
1163,1152,0,47,4,0,57,0,57,14,15,0,0,1,550,3300,0,50,3
1163,1151,0,38,3,0,57,0,57,14,15,0,0,1,450,3300,0,50,3
1163,1151,0,30,2,0,57,0,57,14,15,0,0,1,350,3300,0,50,3
1163,1150,0,21,2,0,57,0,57,14,15,0,0,1,250,3300,0,50,3
1163,1149,0,12,1,0,57,0,57,14,15,0,0,1,150,3300,0,50,3
1163,1149,0,4,0,0,57,0,57,14,15,0,0,1,50,3300,0,50,3
1163,1150,0,0,0,0,57,0,57,14,15,0,0,1,0,3300,0,50,3
1163,1149,0,0,0,0,57,0,57,14,15,0,0,1,0,3300,0,50,3


Case 3 :  1163,57,1,1300,0,50

Charge session starts and ramps up as expected. Charge rate remains steady at 1300W until 1163 is shown on DigiNow and BMS. Voltage climbs one more to 1164 and DigiNow starts ramping down at -100W per tick (apart from first tick) but it appears the DigiNow voltage has latched to 1164. The BMS correctly reports the sagging voltage as the charge rate tails off but the DigiNow does not sag and does not realise it can continue to charge. It tails off evenly to zero and terminates the charge.

Here is the tail of that log...

1163,1163,0,111,10,0,57,0,57,15,16,0,0,1,1300,1300,0,50,3
1163,1163,0,111,10,0,57,0,57,15,16,0,0,1,1300,1300,0,50,3
1164,1164,0,98,10,0,57,0,57,15,16,0,0,1,1150,1300,0,50,3
1164,1163,0,90,9,0,57,0,57,15,16,0,0,1,1050,1300,0,50,3
1164,1162,0,81,8,0,57,0,57,15,16,0,0,1,950,1300,0,50,3
1164,1162,0,73,7,0,57,0,57,15,16,0,0,1,850,1300,0,50,3
1164,1161,0,64,6,0,57,0,57,15,16,0,0,1,750,1300,0,50,3
1164,1161,0,55,5,0,57,0,57,15,16,0,0,1,650,1300,0,50,3
1164,1160,0,47,4,0,57,0,57,15,16,0,0,1,550,1300,0,50,3
1164,1160,0,38,4,0,57,0,57,15,16,0,0,1,450,1300,0,50,3
1164,1159,0,30,3,0,57,0,57,15,16,0,0,1,350,1300,0,50,3
1164,1159,0,21,2,0,57,0,57,15,16,0,0,1,250,1300,0,50,3
1164,1157,0,12,1,0,57,0,57,15,16,0,0,1,150,1300,0,50,3
1164,1156,0,4,0,0,57,0,57,15,16,0,0,1,50,1300,0,50,3
1164,1156,0,0,0,0,57,0,57,15,16,0,0,1,0,1300,0,50,3
1164,1155,0,0,0,0,57,0,57,15,16,0,0,1,0,1300,0,50,3

It looks like no matter what I ask the DigiNow to do, it will not complete a full charge. If I set 1164 as the target voltage in the app, the bike's BMS overrides and terminates immediately that 1164 is exceeded. If I set 1163 as the target, the Diginow begins to ramp down but does not detect the sagging voltage so does not attempt to squeeze any more into the battery.

In addition, really low charge rates such as 200W are not detected by the bike display at all and it just shows the bike as resting at the End of Charge point even though the app shows the DigiNow still pushing at 200W and the voltage (very slowly) climbing.

[Richard230]

I will add that (not surprisingly) Zero's BMS programming seems to have changed over the years.  On my 2014 S, the charger power input would taper from around 1350 watts to 800 watts to 250 watts, before dropping to 7 watts and then shutting off when the battery pack was fully charged. This process would occur over a period of just a few minutes. That bike would (when everything was working properly) charge to 117 volts, according to the Zero app.  However, my 2018 S charges at a maximum of 1450 watts and then shuts down at 116 V without tapering the charge.  I might also add that the 2014 Zero was using the older Calex EVC-116-1200 charger model, while my new bike uses the new (hopefully longer lasting) EVC-116-1300 version.

[NEW2elec]

Yes Richard same here.  I just got another kill-a-watt and see the same thing on my 17.  My 13 tapers off near the end of charge same as your 14, but has the 4 Meanwell units.  The app was showing the 17's amps jumping all over the place so I wanted to see what the kill-a-watt said.  It's much more consistent than the app says.

[DonTom]

I might also add that the 2014 Zero was using the older Calex EVC-116-1200 charger model, while my new bike uses the new (hopefully longer lasting) EVC-116-1300 version.

Which do my 2017's have?

IAC, I use a couple of Q-chargers, along with the on-board for that reason--even when I am in no hurry to  charge, such as the middle of the night. I figure the less time the on-board must run, the less heat inside it for as long. So I assume faster charging from external sources will extend the life of the on-board charger by it being used for  a lot less hours than it would be when run alone.

-Don-  Auburn, CA