Giant EnergyPak 36V battery charges fine with aftermarket charger, but battery % never updates – any workaround?

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Giant EnergyPak 36V battery charges fine with aftermarket charger, but SOC/% never updates – any workaround?


Innlegg:


Hi,


I have an older Giant Aspiro e-bike with a Giant EnergyPak 36V 10Ah (360Wh) rear rack battery.


The original Giant charger (DPS-83CB A, 41.5V 2A) failed, so I replaced it with a generic 42V 2A Li-ion charger and reused the original 5-pin Giant charging cable, using only the VO + and VO -


The battery now charges perfectly:

  • Battery voltage reaches about 41.9V
  • The bike works normally
  • Range seems reasonable
  • The charger correctly switches to "fully charged"

However, the battery percentage appears to be completely wrong.


Example:

  • Bike/display shows 75% (and LED bar on the battery)
  • Battery voltage is 39.5V
  • I charge the battery to 41.9V
  • After reinstalling the battery, both the bike display and the battery LEDs still show 75%

Seems like the original Giant charger will signal to the battery that when fully charged it will show 100% in the display, and this function is lost with an aftermarket charger, using only VO+ and VO-?

Any workaround?
 
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Great to see your Aspiro still going strong and well done with charger re-wire. Generally the battery BMS controls everything and the firmware will simply measure the battery voltage and adjust the LED display, which is the case with recent models.

If the LED display is showing 75% three quarters full and battery is same (3/4 LED's) the measurement could be correct. Batteries will lose full capacity over time and never achieve 100%.

Try leaving the charger on longer and see if the stage 3 trickle charge tops the battery further. Heading back to old charger, did it always reach and report 100% previously ? Charging with an inline ammeter / watt meter can provide good feedback. Handy diagnostic tool.

 
I slept on this. Your 42V generic charger may not be calibrated correctly and is falling short in the stage 1 constant current or stage 2 constant voltage phases and the BMS is reacting strangely and turning off the tap when it thinks it's full.

You could test this roughly by depleting the battery and timing the recharge. 10.4A battery / 2A charger = 5 hours or so. 75% fill is around 4 hours ?

ouer1.webp
 
offroad said:
I slept on this. Your 42V generic charger may not be calibrated correctly and is falling short in the stage 1 constant current or stage 2 constant voltage phases and the BMS is reacting strangely and turning off the tap when it thinks it's full.

You could test this roughly by depleting the battery and timing the recharge. 10.4A battery / 2A charger = 5 hours or so. 75% fill is around 4 hours ?
Click to expand...

@offroad Thanks for your reply. I didn't get notification that anyone had replied on this thread.

I tried depleting battery to 9% (which seems to be the lowest percentage the display will show). I fully charged it again with the new charger. When it was fully charged I measured 42V which shows it was indeed fully charged. When I turned on the display it still showed 9% battery and the bars on the battery (when pushing mode button) also showed empty battery, but the bike worked well. So I assume that the charger is charging battery full, but the BMW did not update the battery status.

I borrowed an original Giant charger from a friend and then the battery status was updated after charging.

I bought a 0-100V battery indicator I planned to mount to check battery status, but I hoped to find a solution for the BMS to update the battery status so that i could see it in the display
 
offroad said:
Sorry, I assumed you had a 3 pin XLR plug, not the 5 pin version which uses the extra pins to communicate between charger and BMS using a switched serial signal. A simple LED bar voltage meter wired inline will give you feedback. I manually use a meter on my Chinese bike with a DC 2.1mm socket.

Click to expand...

I installed a voltmeter and was very happy with that solution until the original display showed 3% and it turned off the assistance… so now I cannot use the aftermarket charger because even if I charge it full it will not update bms and will still show 3% and assistance shut off.

Any chance to manually give the bms a signal that battery is full? Or is the only solution to buy a original giant charger ?
 
When you plug in the charger, did it get warm after 30-60 minutes of charging ? Current Giant 5 pin battery charging circuit uses one pin for charging and different pin for discharging. You can charge the battery on the positive discharge port by co-incidence. Maybe the wiring is wrong ?

Also, if you have old charger check continuity on other 3 wires. Current Giant GLU180A 5 pin charger appears same wiring which has fuse inside which can be repaired / replaced.

8718717419832_N002_1920x1920.webp
 
offroad said:
When you plug in the charger, did it get warm after 30-60 minutes of charging ? Current Giant 5 pin battery charging circuit uses one pin for charging and different pin for discharging. You can charge the battery on the positive discharge port by co-incidence. Maybe the wiring is wrong ?

Also, if you have old charger check continuity on other 3 wires. Current Giant GLU180A 5 pin charger appears same wiring which has fuse inside which can be repaired / replaced.

View attachment 188025
Click to expand...
If you are talking about the faulty giant charger then yes, it got warm, but no output voltage. I opened it and there is no fuse in that charger.
 
The fuse is usually wrapped in black heat shrink plastic and soldered directly to the board. Photo here from the 6A charger tear down:


offroad

Thread 'Giant GLI270 6A EnergyPak 5 pin charger tear down / repair / fuse replace'

Case secured with 4 x Torx screws underside. Double tab fasteners along both sides centre need leverage to unclick.
IMG_6577.JPG


IMG_6579.JPG

White rubber gasket occupies surrounding groove. Unclip aluminium covers, 2 clips each side ends. Unclip LED daughterboard / switch. Bottom aluminium heat sink is stuck to case with glue or tape, prise upwards.
IMG_6581.JPG

Top aluminium cover has soldered earth wire. (Remove temporarily for convenience).
IMG_6582.JPG

If no LED's light, check input fuse F1 adjacent IEC AC input socket.
IMG_6585.JPG

If LED's light, but less than 40v DC output and...
  • Like

offroad

Thread 'Giant GLI180 4A EnergyPak 5 pin charger tear down'

The case is plastic welded on all 4 sides, no clips to simply open. Use a hobby tool (Dremel) to split the case. Caution: Lots of fine black dust particles.
IMG_6535.JPG
Internally, the circuit board is wrapped in aluminium sleeve which acts as heatsink. When you cut and the silver appears, you are through.
IMG_6541.JPG
Input circuit has 5A fuse wrapped in heatshrink next to AC socket. If your LED's are dead, you might be lucky and just need to replace fuse. De-solder to replace.
IMG_6544.JPG
CANBUS daughter board mounted vertically off PCB. 5 pin connector to integrated LED and 60%...
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offroad said:
The fuse is usually wrapped in black heat shrink plastic and soldered directly to the board. Photo here from the 6A charger tear down:



Click to expand...


I cannot find any fuse on this charger. The LED is on, the charger gets hot and I’ve checked the input side with a voltmeter and it seems to be working. Not voltage on the output side

IMG_6664.webp


IMG_6665.webp
 
Good photos. Fuses are generally on the input side so with LED lit, you can assume it's not blown fuse. Sometimes they are soldered under the board using a flat surface mount fuse, component is normally labelled F(1) accordingly on Delta branded chargers which this is. (Logo on input end).

Looking at the output wire colours, appears brown (V0) and black (G?) voltage wires and three thinner, white (VS), orange (TH1), red (?) wires which appear as signalling. Later Giant chargers adopted yellow, green, red/pink for Canbus wiring.
 
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