I’m still running without a bms so I’m just using the 177 profile on my deltaQ. It’s specs say shut off at 98.5, but my meter is showing 99 full pack voltage when I have green light on charger. Once I have a bms installed I’ll be setting cell voltage at 4.05 to enhance battery life. Right now still looking for speed, not range so will be doing a motor upgrade one of these days.
Didn’t have much chance for distance tests today, but easy 36-38 mph on flat ground with just me in it. 7.5 miles and only two bars gone. Charger said 84% charged. Once I hit my low voltage limit I’ll reset the stock soc gauge.
@Inwo I’ve reconfigured my BMS modules for 4.05v/cell and charging cuts off at 4.01V so I’m seeing 88.4V after it settled over night and that throws the -16( over voltage ) alarm. I’m considering adding another diode drop but I realize that what I take off the top also comes off the bottom. ie if I drop the voltage the controller sees when full it also sees less than real voltage at the bottom. This limits capacity available.
Is your voltage spoof using active components to drop the spoof voltage or is it passive like my diode chain? I know the top voltage will probably drop within operating range if I could get it driving for just a bit and will start thinking about a transistor or something to handle the extra drop needed.
Thoughts?
I’m using inwo’s spoof of 16v. My top charge is right about 99v and settles to 98v. He put in a toggle switch to bypass the spoof if I ever get to a low enough charge to need it. I haven’t yet. My gem doesn’t like to see any voltage over about 82.5 so that’s why I choose 16v for the spoof.
Haven’t run low enough to turtle with the high voltage conversion and I can get a solid 23-25 miles range at 35 mph with some small hills. Running the volt packs. very happy with the conversion.
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You can use a zener and pass transistor to get a fixed voltage drop. Google it or I can look through my notes.
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I’ll look into it but I’m considering the physical switch option mentioned by Hbbill. I’d like to make some kind of “feature” panel which would be exposed inside the compartment on the dash.
Things been thinking about are:
XT60 connector with full battery voltage on it.
XT30 connector with 12V( 12.9VDC ) on it
3 pin JST connector with access to last and 2nd to last diodes of the voltage spoofer.
FWIW, my battery was at 88.2V and I put a 2.5A load on the 12VDC radio connectors and that was enough to start functioning. Drove 10 yards up and then down the street and now it’s good to go at 88.0V
If I still had incandescent brake lights and head lights those probably would have worked to pull off the little extra charge but the LED lights pull so little. I’d set the BMS modules cuttoff voltage at 4.05 volts and figured they’d sag back a little to bleed of the 1.1 volts over 88V but it only bled down .5 or .6V. Should try 4.04 but I like the 2 stage switch because if anything it gives more low end battery usage too.
22S Gen4 Leaf modules…
It only needs a momentary “push to start” switch if your ok with normal cutoff.
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Great way to bleed over voltage safely is an electric water heater element. I got the cheapest <$20 element available at the local Lowe’s store. Pu a couple of leads with alligator clips on, dropped in bucket of water and was shedding 1 full volt every 10 minutes on a direct linear rate.
No worries with the spoof, I’m safe at full charger cutoff voltage now.
Thanks again to inwo.
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@Inwo or others,
Is there a video of a voltage spoof installation?
I have a Think with a D2 though I’m guessing it’ll be similar to a Gem.
Just in the back instead of the front. 