: Absolute best practices for prolonging battery life?



world2steven
12-28-2012, 10:49 AM
I just took delivery of a new 2013 and am interested in employing the absolute best practices for prolonging its battery life. I can think of two relatively specific questions at the moment but would appreciate any suggestions and comments on anything related to the general question. The specific questions are:

1- should I leave the charger plugged in as much as conveniently possible? I believe the manual suggests this. And while ambient air temperatures are at extremes, like below freezing or above 90, I intend to observe this recommendation. But what about gray areas, like slightly above freezing or slightly below 90? I was told with my LEAF battery that it was a best practice to NOT charge it all the time to 80% insofar as my driving requirements permitted.

2- I will have the option of driving another car when outside air temperatures approach or exceed 90 degrees. Should I? I realize the Volt can take care of itself for a limited period of time. Is this extra level of babying worth burning a little gas?

bro1999
12-28-2012, 12:01 PM
1 - Straight from the manual: "Keep the vehicle plugged in, even when fully charged, to keep the high voltage battery temperature ready for the next drive. This is important when outside temperatures are extremely hot or cold."

2 - I say just drive the Volt and skip the other car. GM did extensive testing on the battery in extreme weather conditions (-40 to 120 degrees F) so unless you are driving next to molten lava, just drive your Volt!

ari_c
12-28-2012, 12:14 PM
If my Volt is in the garage, it is plugged in. I plug in probably 2 -3 times / day. So I probably have charged it (not fully) over 900 times.

Most days I discharge to 5% of what is reported by the car. I now have over 21,000 EV miles and have not seen any appreciable drop in my range compared to a year ago.

I have not seen extreme temperature ranges here in Virginia, but the nice thing about the Volt is the thermal management for the battery.

Just keep it plugged in and don't worry about it as the battery has an 8 year/100,000 mile warranty.

ewiggins
12-28-2012, 12:15 PM
If my Volt it at home, it is plugged in. I have had it since Feb 2012 and have not seen the battery dropt in miles except when it gets really cold. The battery returns to its usual when the temps warm up.

If you have a 240 charger, you will want the car plugged in so if you precondition your car, you will not use up the battery.

HiVOLTage
12-28-2012, 12:32 PM
I agree with PLUG1N,,,,, partial depletion and recharge is best. You can get info on Lithium batteries for notebook computers and will see the depth of charge vs life expectancy. The volt has a smart charger that reduces the current at the end of cycle whereas most notebook chargers are called bricks...as dumb as a brick.

fotomoto
12-28-2012, 12:47 PM
Keep it plugged in as much as possible so the TMS will run off the wall instead of the battery. Keep it out of the sun as much as possible to make life easier for the TMS.

Ideally for AZ? Work the night shift and garage/plug-in/sleep during the day!!! LOL

MrEnergyCzar
12-28-2012, 02:21 PM
There's nothing to do differently other than plug it in a little more, the Volt takes care of itself. The Battery is expected to last 13-19 years or lose 10-30% after about 9 years thus dropping the range to 28 miles in a worse case scenario...

MrEnergyCzar

DonC
12-28-2012, 02:33 PM
Simple advice:

1. Don't live in a hot place like Phoenix or Palm Springs
2. Make sure you follow one.

Ha ha. But seriously there isn't much that can hurt the battery other than very hot weather and very fast discharges. Plugging in can help with the heat but you can't be plugged in all the time. I wouldn't worry too much about the battery though. You'll probably be ready for a new car long before the battery goes kaput.

baragona
12-28-2012, 02:40 PM
Living here in Phoenix, I plug in whenever I can. Plugging in 100% of the time during the hot weather is actually "better" as the battery Temperature Management will run, when necessary, to keep your battery at the optimum temperature.

I drove the Volt all summer long even in 118 degree weather. While the EV range was less in the summer from increased energy usage by the AC and TMS, the battery itself is doing quite well and has not lost a bit of capacity after 1 year. As the weather cooled down in the fall, my EV range increased back to what it was in the spring.

As far as comparing it to the LEAF best practices, the active battery TMS and the Volt only using 10.5 out of 16 KWH give the Volt a clear edge for battery life, and eliminate the need to take some of the measures that might be required with a LEAF.

I would drive the Volt all the time. Just be mindful that the range will decrease in the hot AZ summer, but will increase in the fall, and stay that way until the next summer.

Congrats and don't worry....


I just took delivery of a new 2013 and am interested in employing the absolute best practices for prolonging its battery life. I can think of two relatively specific questions at the moment but would appreciate any suggestions and comments on anything related to the general question. The specific questions are:

1- should I leave the charger plugged in as much as conveniently possible? I believe the manual suggests this. And while ambient air temperatures are at extremes, like below freezing or above 90, I intend to observe this recommendation. But what about gray areas, like slightly above freezing or slightly below 90? I was told with my LEAF battery that it was a best practice to NOT charge it all the time to 80% insofar as my driving requirements permitted.

2- I will have the option of driving another car when outside air temperatures approach or exceed 90 degrees. Should I? I realize the Volt can take care of itself for a limited period of time. Is this extra level of babying worth burning a little gas?

jfkirk
12-28-2012, 02:42 PM
Here are some additional hints for incremental life gains.

1. If unplugged do not leave it sitting in the sun on a hot day....park in shade...if charged the TMS will reduce range.
2. Drive gently, you will increase range and lower discharge/regen charge rates. (common sense)

Bob G
12-28-2012, 02:59 PM
Keep it plugged in as much as possible so the TMS will run off the wall instead of the battery. Keep it out of the sun as much as possible to make life easier for the TMS.

Ideally for AZ? Work the night shift and garage/plug-in/sleep during the day!!! LOL

Or, plug it in during the heat of the day so that the battery can keep itself cool.

baragona
12-28-2012, 03:02 PM
If you do have to leave it unplugged in the hot sun, try to make sure you have some charge left in the battery so that the TMS can run while parked.

Through last summer, the most I saw the range decrease after leaving the Volt parked in the sun all day was about 2 miles...


Here are some additional hints incremental gains.

1. If unplugged do not leave it sitting in the sun on a hot day....park in shade...if charged the TMS will reduce range.
2. Drive gently, you will increase range and lower discharge/regen charge rates. (common sense)

alex
12-28-2012, 04:15 PM
If you do have to leave it unplugged in the hot sun, try to make sure you have some charge left in the battery so that the TMS can run while parked.

Through last summer, the most I saw the range decrease after leaving the Volt parked in the sun all day was about 2 miles...

Do you know what charge has to be in the battery for the TMS to run? I though I read it had to be > 70%

jfkirk
12-28-2012, 04:51 PM
Do you know what charge has to be in the battery for the TMS to run? I though I read it had to be > 70%

Don't have a reference to cite, but based on experience its probably lower...say 50%

alex
12-28-2012, 05:24 PM
Don't have a reference to cite, but based on experience its probably lower...say 50%

How can you tell? Do you just hear it come on while it is in a parking lot?

jfkirk
12-28-2012, 07:57 PM
How can you tell? Do you just hear it come on while it is in a parking lot?

You can see the range and SOC drop over an afternoon...in my case over 90 and a black parking lot. But, yes I can hear a whine and my car has a slight flow noise in the front I can hear if it is quiet. A little deaf, so I am sure a younger person could hear it more readily.

Bob G
12-29-2012, 02:29 AM
If you do have to leave it unplugged in the hot sun, try to make sure you have some charge left in the battery so that the TMS can run while parked.

Through last summer, the most I saw the range decrease after leaving the Volt parked in the sun all day was about 2 miles...

I learn something new every day! I didn't know that the Volt would keep its battery cool without being plugged in - another great idea implemented in an amazing car! We in Seattle are lucky to get a handful of days each year above 80, so this is something I'll likely never see.

GSP
12-29-2012, 07:29 AM
While the Volt will cool the battery when unplugged at high SOC and very hot, it will keep the battery cooler when plugged in. So plugging in when hot is better. Parking in the shade when a plug is not available is good advice.

Likewise, when very cold the Volt will heat the battery when plugged in. Unlike when hot, it will not heat the battery when unplugged.

So, best advice for long battery life is to plug in when not moving, and drive gently.

GSP

world2steven
12-29-2012, 02:43 PM
Thanks for all the feedback. Does anyone know the exact trigger temperatures for battery heating and cooling? 32 and 90? Does it make sense to take EXTRA SPECIAL care to insure the car is plugged in when temperatures even approach these trigger points?

mikeg3
12-29-2012, 04:27 PM
Another measure to protect the battery, right out of the owner's manual, is to use the Volt car cover. I found it to be quite effective in very hot, sunny weather. Someday there will be chargers everywhere. Until then, we can take reasonable precautions.

BTW, your Volt battery has many years of life in it even beyond the eight year warranty and the eventual replacement is only $3000, so don't sweat it (pun intended).

jfkirk
12-29-2012, 06:01 PM
Thanks for all the feedback. Does anyone know the exact trigger temperatures for battery heating and cooling? 32 and 90? Does it make sense to take EXTRA SPECIAL care to insure the car is plugged in when temperatures even approach these trigger points?

Here is an old link with a discussion. In particular look at post 121. Also I stand corrected, looks like the threshold is 75% for not plugged in cooling, not 50% SOC. It clearly explains why the car should be plugged in.

http://gm-volt.com/forum/showthread.php?5243-Volt-thermal-management-system-temperature-band/page13

mfennell
12-29-2012, 08:36 PM
I gathered the OP was interested in the absolute best *OCD* practices for prolonging battery life. :)

Two thoughts if you really want to work the margins:

1) Run a pre-cool midday if the car is out unplugged in the blazing Tuscon sun to pull the temp back down and minimize heat soak. WOT previously confirmed that TMS will run and cool the battery during pre-cool. The auto-TMS only runs at very high (75%, as noted above) battery charge. I took that to mean TOTAL charge, not percentage as shown on the gauge. Please correct if I'm wrong.

2) Set to charge based on departure time. That will minimize time spent at max charge. I know it's only ~82% but still...

Does DashDAQ pull battery temp?

jfkirk
12-29-2012, 08:45 PM
I gathered the OP was interested in the absolute best *OCD* practices for prolonging battery life. :)

Two thoughts if you really want to work the margins:

1) Run a pre-cool midday if the car is out unplugged in the blazing Tuscon sun to pull the temp back down and minimize heat soak. WOT previously confirmed that TMS will run and cool the battery during pre-cool. The auto-TMS only runs at very high (75%, as noted above) battery charge. I took that to mean TOTAL charge, not percentage as shown on the gauge. Please correct if I'm wrong.

2) Set to charge based on departure time. That will minimize time spent at max charge. I know it's only ~82% but still...

Does DashDAQ pull battery temp?

The DD pulls average battery temp, and can see the pump and valve. Good point with delaying.

Purplegate
12-30-2012, 11:33 AM
I would also get from the OP he is looking for the do and don’t for maintaining longer life of the battery (not more usable SOC on a daily basis when/where plugged). I also have the same question as OP. In the previous “world” with Ni-MH batteries (Prius, Civic/Insight…), the failed batteries were diagnosed with only one or few weaker cells. Cells that degraded overtime and once a cell becomes weak, the power is always first drawn from it making its burden higher every time the car is used, thus reducing its life faster.

Some battery refurbishing companies started to pop and they offer replacement of failed cells only, making it way cheaper than a full new pack. Then some “smart” battery charger started to be built. Non-plugin hybrids should not need to be charged from the grid, however, it was found that “topping” the cells on a regular basis (still talking about Ni-MH) at a very low charging rate would be beneficial as it equalize all the cells in the pack, and avoid always drawing from the same cell first all the time when the car is used.

Now, back to Li-ion like the Volt, I would think this can be part of the question of the OP (correct me if I’m wrong). Is the Li-ion needs the same caring as Ni-MH and will the power start to be drawn from one cell when it weaken? Then is the Volt charger smart enough to do this cell balancing/topping? If not, how to minimize the risks or unbalancing cells?

Also, taking the example of a laptop Li-ion battery (laptop, phone, camera…), it’s a good practice to fully discharge it once a month and fully recharge, which rebalance the pack. Some laptops even have a “maintenance mode”, in which it will discharge and recharge the pack during the operation. Would it be a good practice to do so also with the Volt, mainly for someone who does not discharge the whole pack often (i.e. short commute)?

Other point, on many Li-ion (computer, camera…), leaving it plugged at all time will reduce the life as once topped, it still keeps drawing small current and generate unneeded heat in the cells, or if not well controlled, will push more current that the cells are capable of taking (kind of pushing electrons when the cup is already full… it will spill…). How does the Volt controls this?

world2steven
12-31-2012, 10:39 AM
Here is an old link with a discussion. In particular look at post 121. Also I stand corrected, looks like the threshold is 75% for not plugged in cooling, not 50% SOC. It clearly explains why the car should be plugged in.

http://gm-volt.com/forum/showthread.php?5243-Volt-thermal-management-system-temperature-band/page13

This is great stuff! It looks like the take-away is: plugging in when outside air temps are above 72 or below 25 is NOT overkill. (Doesn't the manual say the TMS comes on at 32 degrees?)

P.S. Looks like this chart should be in the manual!!

mikeg3
12-31-2012, 11:43 AM
This is great stuff! It looks like the take-away is: plugging in when outside air temps are above 72 or below 25 is NOT overkill. (Doesn't the manual say the TMS comes on at 32 degrees?)

P.S. Looks like this chart should be in the manual!!
TMS operation is based on the battery temperature, the State of Charge, whether the Volt is plugged in, whether preconditioning is in effect, whether the Volt is turned on, and possibly the outside temperature.

WOT has access to the real parameters and seems to consider them a GM trade secret - fair enough.

The general idea is that a hot battery with a high SOC is vulnerable to increased loss of capacity. The TMS is used more when the Volt is plugged in or turned on, but it will come on for an unplugged, parked Volt in extreme cases. Nothing I said is either controversial or quantitative.

I suppose that a patient driver with a DashDAQ could work out the numbers, but what's the point? With an 8 year warranty and a $3,000 battery replacement cost, I'm more worried about ICEd EVSEs than a hypothetical issue that might come up around the time Google's self driving cars cause me to become an innovator again.

If you're still worried, use a Volt car cover as recommended in the owner's manual.