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I am likely to be forced to use a Volvo V60 in its hybrid diesel-electric plug-in version for my daily commutes. This is a hybrid system comprising a 2.4l diesel engine with an added plug-in electric motor (ERAD). The electric motor is powered by a 12 kWh lithium-ion battery pack which needs to be plugged-in the mains for ca. 8h to be fully charged. Ideally one would do this at night or at work during the day.

The problem is that I have nowhere to charge it on a daily basis. For starters my garage has no electricity. I can maybe try to find a plug somewhere in the garage at work but that's not a sure deal. Moreover, in the town where I live there are sparse charging spots near supermarket or in underground parkings. Therefore, if I end up getting this car I will be using mainly the diesel engine, and will rarely charge the battery.

I know I can drive the car using solely the diesel engine. The car will start and operate normally in this configuration. I am wondering however if never/rarely charging the batteries causes harm to the hybrid/electric engine system. Is this the case?

  • Do you mean running it without the hybrid enabled? – anonymous2 Oct 12 '16 at 14:36
  • The car has a 12 kWh lithium-ion battery pack which needs to be plugged-in the mains for ca. 8h to be fully charged. This powers the electric motor part of the hybrid system. If I never/rarely charge this battery, but I still drive the car around normally, will I be damaging the hybrid motor in any way? – JoErNanO Oct 12 '16 at 14:48
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    The car should recharge the battery as it goes enough to cover the amount of energy required to start the engine and run electric systems. The hybrid motor won't be damaged. – anonymous2 Oct 12 '16 at 14:50
  • I am likely to be forced to use a Volvo V60 in its hybrid diesel-electric plug-in version for my daily commutes. vs if I end up getting this car I will be using mainly the diesel engine, and will rarely charge the battery. So, do you have to get this car or not? Can you opt for a less expensive non-hybrid? – MonkeyZeus Oct 12 '16 at 16:18
  • @MonkeyZeus maybe but that's not the scope of this question. ;) – JoErNanO Oct 12 '16 at 18:58
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No, it won't get damaged. But you also shouldn't let the battery totally empty for long periods. Li-ion batteries are best stored with some charge (normally about 40% is recommended charge level for long term storage per battery university :))

Volvo says that if you press the 'save' button your car will keep reserve charge or charge the batteries from diesel engine, for at least 20km of driving with electric motor:

Volvo V60 hybrid save mode

This should be good enough to keep batteries in good condition.

  • Now that's the documentation I was looking for! – JoErNanO Oct 12 '16 at 14:56
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    You don't need to use the Save button. The battery gets charged (and discharged) during normal driving. The Save button stops the discharge for a while, to make sure the battery is full when you want it. – Hobbes Oct 12 '16 at 15:38
  • @Hobbes 15 , in that case the battery level will simply stay near empty. The battery WILL NOT get charged to a reasonable level. Because it is less energy efficient to charge car's batteries from diesel engine and uses more fuel. Therefore car will not attempt to fully charge the batteries using the diesel engine. – Evren Yurtesen Oct 13 '16 at 6:56
  • You're confusing two things. In Hybrid mode, not enough electric power is generated to fully charge the battery. But the battery is charged (a bit) every time you brake. In the V60, the battery is in regular use in all drive modes. So it's not necessary to use the Save button to keep the battery healthy, you just need to use the Save button if you want to drive the V60 as a fully electric car. – Hobbes Oct 13 '16 at 8:55
  • No, brake pedal do not help charging the battery in hybrid cars. Hybrid cars have regular brakes for that. But when you release your foot from gas pedal, it can recharge while car is slowing down. Go and read some manuals. The charging happens only when you do engine braking and NOT when you press the brake pedal. See: support.volvocars.com/kr/cars/Pages/… – Evren Yurtesen Oct 13 '16 at 9:55
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The car will charge its battery while driving, e.g. when you brake. This allows the electric motor to augment the diesel engine, reducing overall fuel usage. The result is that the charge state of the battery constantly changes. In other hybrids (Toyota Prius) the control system keeps the battery charge in a range that optimizes battery lifetime (i.e. battery is not drained completely and not filled completely). I expect Volvo to do something similar.

Conclusion: you don't need to take manual action to keep the battery healthy. Even when you never charge the car from the mains, the control system will keep the battery healthy.

From the V60 manual:

The electric motor's engine brake is used during light braking. The car's kinetic energy is then converted to electrical energy instead, which is used to charge the hybrid battery. Battery charging with engine braking is indicated in the combined instrument panel with animation.

This function is active in the speed range 150-5 km/h - for harder braking, as well as outside the speed range, the braking is complemented by the hydraulic brake system.

If you want to drive using only electric power, you can fully charge the battery using the Save button.

The plug-in circuit allows you to charge the battery at home, so you can run on electric power some of the time and reducing fuel usage some more.

Is the company providing you with the car? Then they should also provide somewhere to charge it.

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    Expecting a company to (re)wire your garage just because they're providing you with a car isn't realistic. Pointing out that because you don't have the ability to charge it, a plugin electric would actually be less green and more expensive (to them) than an equivalent conventional hybrid model (eg the larger battery/etc become dead weight) might be able generate traction for getting a different model; but if they're buying a number of identical cars at once and getting a volume discount they still might prefer to buy the plugin hybrid anyway. – Dan Neely Oct 12 '16 at 17:15
  • Seems immoral to buy a plugin hybrid, get a tax break because it's a plug-in and then not use it the way it's meant to be used. – Hobbes Oct 12 '16 at 17:23
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    I agree it'd be stupid to do so, but one size fits all benefits often end up being poor fits for a portion of the workforce so there's nothing special there. ex a large life insurance policy is probably worth a fair amount to someone with a spouse or minor children, but not so much to someone who's unattached ("I'd be dead then, what's the point?"). – Dan Neely Oct 12 '16 at 17:32
  • You should read up on hybrids. All hybrids use the electric motor as a dynamo when you press the brake pedal. The system divides braking effort between the brakes and motor. The V60 online manual states: "The electric motor's engine brake is used during light braking. " – Hobbes Oct 13 '16 at 8:52
  • Did you read the page you just linked to? Specifically the heading "Light braking - hybrid battery charging". Hybrids use BOTH friction brakes and the electric motor when braking. – Hobbes Oct 13 '16 at 10:12

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