GM Volt Forum banner

1 - 20 of 24 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Because I live on top of a mountain I need dynnamic braking starting froom home. If the battery has fully charged non is available and I need to ride the brakes. How can I limit the charger to leave some room for braking?
 

·
Registered
Joined
·
433 Posts
If you're in a Bolt, then utilize the Hill Start mode. If you're in a Volt, you can utilize delayed charging and set the timer to start charging a few hours after you plug in versus charging immediately.
 

·
Registered
Joined
·
1,118 Posts
Don't forget that the Volt has a charging schedule that can be programmed. If you know you're always leaving at a specific time then you can adjust the car to have charging "complete" after that time. This should tell the car it has plenty of time to charge before your programmed departure time. Unplugging early of course means you won't have a full charge and have the additional battery capacity for regen storage. On the other hand, placing the shift lever in L will offer additional regen that D may not have even when the battery is fully charged.
 

·
Registered
Joined
·
464 Posts
As Freshcut is saying, the simple answer is to set the departure time later than you normally leave.

If you have level 1 charging set it one or two hours after you will really leave.

If you have level 2 charging, try setting it 15 minutes (or 30 if you need some buffer) after you plan on leaving.
 

·
Registered
Joined
·
188 Posts
I don't understand. You are saying if you have a fully charged battery that you don't have regen braking? The braking should act the same whether the battery is full or not. The regen will not add to a full battery but should still do the braking in the L position.
 

·
Registered
Joined
·
678 Posts
No, because the energy from regen has to go somewhere and if the battery is full, it can't go there... The only other option would be to turn it in to heat via opposing electric motors or the like...

I don't understand. You are saying if you have a fully charged battery that you don't have regen braking? The braking should act the same whether the battery is full or not. The regen will not add to a full battery but should still do the braking in the L position.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #8
Variable leaving times.

I always drive in L. I'm on a mountain. About half way down the regen gives up. Battery too full
I only drive the car every two or three days. I need to stop the chargger at 90%. I come home with a variable charge left. How would I know when 90% is reached?
 

·
Registered
Joined
·
4,746 Posts
In the winter you can use the preconditioning feature to preheat the Volt. If you precondition the Volt while not plugged in this will draw up to 8kW from the battery for 10 minutes or 20 minutes (if you press the remote start button a second time to extend the preconditioning cycle for an additional 10 minutes.) Most of the energy needed to precondition the Volt is normally put back into the Volt's battery if you precondition while plugged in. By not being plugged in you should be able to start your downhill run with your Volt showing 1 to 2 bars down on the battery gauge and the inside of your Volt will be warm.
 

·
Registered
Joined
·
317 Posts
Tomt, lift your foot in L with a full charge. No regen, but usually within a mile or two of stop and go, regen will be restored.
 

·
Registered
Joined
·
1,488 Posts
Because I live on top of a mountain I need dynnamic braking starting froom home. If the battery has fully charged non is available and I need to ride the brakes. How can I limit the charger to leave some room for braking?
The Volt has cool technology that will harmlessly bleed off your excess energy without wearing out the brakes. But that is wasting energy, one of the points why I wanted to go electric drive. I agree with the others that it would be better to either end up with less than a full charge through programming your charging, or unplug after a full charge and precondition the cabin of the car.
 

·
Registered
Joined
·
2,259 Posts
In Gen 2, L will work with full battery but the paddle won't add more re-gen. It took a while to realize it only happens with a full battery when starting downhill.
 

·
Registered
Joined
·
1,605 Posts
If you are driving a Volt, you might know there’s only a small overflow buffer above the "full charge" battery SOC level. If you live at the top of a hill and start the day with a full charge, the downhill regen at the start of your daily drive quickly fills that buffer, and braking must be accomplished by other means because the battery is at its maximum allowed SOC level. (And, once you can’t put any more regen into the battery, reports indicate that distances are recorded as Gas miles/km. I suspect this is because conditions no longer meet the criteria for Electric Mode driving.) Not sure if Gen 2 has modified the propulsion configuration to avoid this problem.

You have options:

Use delayed charging to set the "full charge" time target to a time after you normally depart, so the car is not yet fully charged at your normal departure time.

Unplug the car in the morning, then use remote start to precondition the car, setting the climate controls for extra heat (or extra cold air conditioning?), producing power consumption prior to departure, leaving more upper buffer room for regen as you head downhill.

Perhaps if you start blasting out the heat (or air conditioning) as you start your drive in the morning, the power draw for the cabin heating/air conditioning will consume enough of the downhill regen to prevent the overflow buffer from being fully filled by regen. If this creates an uncomfortable environment in the cabin (too hot, too cold), you can always open the windows...
 

·
Registered
Joined
·
5 Posts
Discussion Starter #14
These workarounds may help, but they seem wasteful. I really wouldd like a factory rep to adjust the charger cutout voltage to 90%. Then my trip to town would finish the charge (14 miles). Does anyone at GM read these things?
 

·
Registered
Joined
·
3,783 Posts
..... adjust the charger cutout voltage to 90%. Then my trip to town would finish the charge (14 miles). Does anyone at GM read these things?
Yes And,,, they say the same thing I say: You should have bought a Bolt!
Or deal with it. Adjust the 'departure time' to do what you need your Volt to do.
 

·
Registered
Joined
·
283 Posts
How can I get the dealer to change the full charge setpoint?
They won't. You'll have to figure out how much room you need in the battery, then set your EVSE on a timer to short charge the battery by that amount.

Do a few descents on an empty battery to see what kind of range a decent gives you, then work that backwards to figure out your optimum charging time. If you're coming home with plenty of battery a L1 charger might make this easier.
 

·
Registered
Joined
·
71 Posts
What OP could also do is just use the "instant charging" option but get himself a "digital switching socket" and program the correct timing.

We are missing one piece of information here, how much regen can he do going downhill? if its something like 0.5, he can do a pre-conditioning, if its more, then some timing is needed.
 

·
Registered
Joined
·
283 Posts
I remember the leaf folks grousing about timers on level 2 EVSE's and heavy duty relays and such, when it occurred to me that all you have to do is a simple mod to the proximity detection circuit (1 wire, low voltage, low current) and the EVSE will turn on and off itself, as if you had plugged or unplugged it. Then any on off timer would work. The OpenEVSE lends itself nicely to such tinkering.
 

·
Registered
Joined
·
538 Posts
I admit to being a bit confused here, but interested. We, too, live at the top of a steep hill in Southern California. A full charge these days is 43-48 miles. Going down the hill in L, we have full regen braking and the range increases steadily to 60. I read elsewhere on this forum that a few more miles of range can be added but the display will only show 60. In any case, L works nicely to charge the car but also to keep us from having to use the brakes much during the descent.

If y'all are saying that I could stop charging at, say 30 miles, to gain another 30 in L, then I understand. But there is no problem with regen braking from a full charge, right from the start.
 
1 - 20 of 24 Posts
Top