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Discussion Starter · #1 ·
It has been a while since I have posted a question on this forum. By way of background, I have a 2018 Clarity PHEV Touring purchased new in November 2018 in Wilmington, North Carolina. Build date in Japan was January 2019. Our Clarity has about 22,000 miles on her and most of those miles has been around-town driving with a smattering of annual road trips. As an aside, I have never once had a technical nor mechanical problem with the Clarity. In the almost four years of ownership my only expenses for maintenance and upkeep have been for annual oil and filter changes, changing out the cabin air filter annually and tire rotations as needed.


Now, to my question and/or issue. Prior to April of 2022 the Clarity had been routinely garaged at night at our home and plugged into a Level II Siemens wall charger. However, In April 2022 we sold our home and moved into an apartment while we build a new home. In our new, temporary location, we do not have access to a electric vehicle charger on premises, nor a outside wall outlet to use the charging cord that came with the Clarity. The nearest charging stations to our current address require me to drive fifteen minutes or so and then wait upwards of an hour or more to keep the battery topped up when needed. Such a routine as this wouldn’t be so onerous if the weather were milder, but this is North Carolina, on the coast, and we are in the throes of summer now and the heat index can approach and stay in the upper 90’s and lower 100’s for days on end. Plus, we tend to get rain here in abundance on a regular basis. Sitting in or even near my Clarity waiting for it to charge under these conditions is not my idea of fun. (Note: The location of these particular chargers is in an isolated location with no facilities nearby to retreat to and wait.)

Therefore, given these scenarios and these weather patterns, whenever my electric miles reserve falls to the 10 to 12 miles level, I have taken to the routine of using the Clarity’s onboard electrical generator, powered by the ICE to keep the lithium battery, and the 12 volt battery by default, charged to slightly above the 50% charged level on a regular basis as needed when I am out driving around (Note: Specifically, I mean by holding down the “Hybrid” button for two seconds until “Charging” icon appears under Hybrid on dashboard). I have been practicing this routine for about the past month and plan on keeping doing it for another month through August. Reason being, we are planning on taking possession of a leased garage in our apartment complex, with a electrical wall outlet in the garage, September 1st. When this occurs I will have access to using the wall outlet to connect the Clarity’s charging cable to in order to maintain charging on a regular and stable basis.

I don’t put many miles on the vehicle under the conditions described above using the generator and the ICE to keep the vehicle charged. My question is: Does anyone on this forum see any problems with THIS routine in general, or with my primarily, for a short period of time only (I.E., for sixty days, on and off), maintaining the lithium battery, and 12 volt battery by default, primarily around the 50% charge level — the level at which I can charge it to using the electric generator using the ICE?

Thanks for any input you might have on these issues.
 

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It has been a while since I have posted a question on this forum. By way of background, I have a 2018 Clarity PHEV Touring purchased new in November 2018 in Wilmington, North Carolina. Build date in Japan was January 2019. Our Clarity has about 22,000 miles on her and most of those miles has been around-town driving with a smattering of annual road trips. As an aside, I have never once had a technical nor mechanical problem with the Clarity. In the almost four years of ownership my only expenses for maintenance and upkeep have been for annual oil and filter changes, changing out the cabin air filter annually and tire rotations as needed.


Now, to my question and/or issue. Prior to April of 2022 the Clarity had been routinely garaged at night at our home and plugged into a Level II Siemens wall charger. However, In April 2022 we sold our home and moved into an apartment while we build a new home. In our new, temporary location, we do not have access to a electric vehicle charger on premises, nor a outside wall outlet to use the charging cord that came with the Clarity. The nearest charging stations to our current address require me to drive fifteen minutes or so and then wait upwards of an hour or more to keep the battery topped up when needed. Such a routine as this wouldn’t be so onerous if the weather were milder, but this is North Carolina, on the coast, and we are in the throes of summer now and the heat index can approach and stay in the upper 90’s and lower 100’s for days on end. Plus, we tend to get rain here in abundance on a regular basis. Sitting in or even near my Clarity waiting for it to charge under these conditions is not my idea of fun. (Note: The location of these particular chargers is in an isolated location with no facilities nearby to retreat to and wait.)

Therefore, given these scenarios and these weather patterns, whenever my electric miles reserve falls to the 10 to 12 miles level, I have taken to the routine of using the Clarity’s onboard electrical generator, powered by the ICE to keep the lithium battery, and the 12 volt battery by default, charged to slightly above the 50% charged level on a regular basis as needed when I am out driving around (Note: Specifically, I mean by holding down the “Hybrid” button for two seconds until “Charging” icon appears under Hybrid on dashboard). I have been practicing this routine for about the past month and plan on keeping doing it for another month through August. Reason being, we are planning on taking possession of a leased garage in our apartment complex, with a electrical wall outlet in the garage, September 1st. When this occurs I will have access to using the wall outlet to connect the Clarity’s charging cable to in order to maintain charging on a regular and stable basis.

I don’t put many miles on the vehicle under the conditions described above using the generator and the ICE to keep the vehicle charged. My question is: Does anyone on this forum see any problems with THIS routine in general, or with my primarily, for a short period of time only (I.E., for sixty days, on and off), maintaining the lithium battery, and 12 volt battery by default, primarily around the 50% charge level — the level at which I can charge it to using the electric generator using the ICE?

Thanks for any input you might have on these issues.
I don’t see any problem in particular with what you’re doing but I’m also not sure that you’re going to get any benefit out of doing it. In my mind, the most logical thing to do would be just to drive it in standard HV mode.
 

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it's a pretty expensive way to charge a high voltage battery, but if that's all you've got...

are you sure that's all you've got? also, it'll charge even with the AC running... just slower

bring a book, NC brother
 

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Unless you plan to leave the car parked for months without starting it, there is no harm in leaving the HV battery as discharged as it will get by driving it normally. The car reserves a portion of the HV battery pack that it won't use for EV range, and if you start the car while it's below the minimum charge level, it will kick on the ICE to restore it to nominal.

If you don't have access to a charger, using the ICE to charge the HV battery higher than necessary is terrible for fuel economy. That's because you're converting gasoline into mechanical energy, then converting mechanical energy into chemical energy in the battery, then back from chemical energy into electricity to power the traction motors to spin the wheels. This is categorically less efficient than using the ICE to directly drive the wheels, which the Clarity will do when you hit about 62 mph in HV mode.

Like ClarityDave said, when you don't have access to a charger, you should drive your Clarity PHEV as if it were a Toyota Prius. That is, drive it like a conventional gasoline car. Turn it on, drive it, turn it off, fill up the gas tank when needed. This is the most efficient way (in terms of fuel consumption) to travel without access to a charger.

The real use case for the "HV Charge" mode is if you have low battery AND need to travel at significant speed uphill. The ICE in the Clarity doesn't have enough power to propel the vehicle steeply uphill (often with some cargo, if you're going camping or something) while also adding energy to the battery. Extremely steep hills can only be climbed with the traction motors' assistance, so in an ideal world you need the battery to be drained during such climbs, so the battery and the engine can work together to produce more power to the wheels.

If you're traveling on flat or gently hilly terrain (routine up and down oscillations, as are common in the mid-atlantic region), you should never need to use HV Charge.

... Unless you plan to leave it parked, without starting it or driving it, for months. Then it might make sense to turn it on, HV Charge it to 40-50% HV, and shut it down. Turning off the vehicle with a low HV state of charge and leaving it that way for a long time risks a flat battery condition, where you'd be unable to restart the vehicle and need to get it towed to restore a nominal charge to the HV pack.
 

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Unless you plan to leave the car parked for months without starting it, there is no harm in leaving the HV battery as discharged as it will get by driving it normally. The car reserves a portion of the HV battery pack that it won't use for EV range, and if you start the car while it's below the minimum charge level, it will kick on the ICE to restore it to nominal.

If you don't have access to a charger, using the ICE to charge the HV battery higher than necessary is terrible for fuel economy. That's because you're converting gasoline into mechanical energy, then converting mechanical energy into chemical energy in the battery, then back from chemical energy into electricity to power the traction motors to spin the wheels. This is categorically less efficient than using the ICE to directly drive the wheels, which the Clarity will do when you hit about 62 mph in HV mode.

Like ClarityDave said, when you don't have access to a charger, you should drive your Clarity PHEV as if it were a Toyota Prius. That is, drive it like a conventional gasoline car. Turn it on, drive it, turn it off, fill up the gas tank when needed. This is the most efficient way (in terms of fuel consumption) to travel without access to a charger.

The real use case for the "HV Charge" mode is if you have low battery AND need to travel at significant speed uphill. The ICE in the Clarity doesn't have enough power to propel the vehicle steeply uphill (often with some cargo, if you're going camping or something) while also adding energy to the battery. Extremely steep hills can only be climbed with the traction motors' assistance, so in an ideal world you need the battery to be drained during such climbs, so the battery and the engine can work together to produce more power to the wheels.

If you're traveling on flat or gently hilly terrain (routine up and down oscillations, as are common in the mid-atlantic region), you should never need to use HV Charge.

... Unless you plan to leave it parked, without starting it or driving it, for months. Then it might make sense to turn it on, HV Charge it to 40-50% HV, and shut it down. Turning off the vehicle with a low HV state of charge and leaving it that way for a long time risks a flat battery condition, where you'd be unable to restart the vehicle and need to get it towed to restore a nominal charge to the HV pack.
I'm confused by the quote:

"Extremely steep hills can only be climbed with the traction motors' assistance, so in an ideal world you need the battery to be drained during such climbs, so the battery and the engine can work together to produce more power to the wheels."

With the battery drained, the Clarity PHEV will struggle up steep climbs (using only the ICE) at speeds above 55 mi/hr or so.

I always try to enter the Grapevine (a notorious pass in So. CA) with at least 50% SOC on the battery, and use HV, so the car tries to keep it there. The ICE will scream at high RPMs as it does so. I monitor the SOC, and if it starts to drop to below about 25%, I slow down, until it stabilizes.

The Clarity PHEV definitely needs both the battery and the ICE on steep climbs at high(er) speeds. Having it drop to a lower performance mode when you're tooling along at 80 mi/hr in the #1 lane can be a bit disconcerting, to say the least.
 

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I'm confused by the quote:

"Extremely steep hills can only be climbed with the traction motors' assistance, so in an ideal world you need the battery to be drained during such climbs, so the battery and the engine can work together to produce more power to the wheels."

With the battery drained, the Clarity PHEV will struggle up steep climbs (using only the ICE) at speeds above 55 mi/hr or so.

I always try to enter the Grapevine (a notorious pass in So. CA) with at least 50% SOC on the battery, and use HV, so the car tries to keep it there. The ICE will scream at high RPMs as it does so. I monitor the SOC, and if it starts to drop to below about 25%, I slow down, until it stabilizes.

The Clarity PHEV definitely needs both the battery and the ICE on steep climbs at high(er) speeds. Having it drop to a lower performance mode when you're tooling along at 80 mi/hr in the #1 lane can be a bit disconcerting, to say the least.
By "need the battery to be drained" I mean that the battery should have charge, so that the vehicle can drain it during travel -- not that you should travel with the battery low on purpose. Sorry, I know that's not clear from the grammar.
 

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By "need the battery to be drained" I mean that the battery should have charge, so that the vehicle can drain it during travel -- not that you should travel with the battery low on purpose. Sorry, I know that's not clear from the grammar.
No worries. I just wanted to be clear, for any lurkers or noobs.
 

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I may be the only proponent of HV Charge on this forum. I use it all the time on long trips. I charge to the max, use the electric, repeat. If I know I will be driving getting off the highway, I save some EV range. In your case I do agree that using charge mode at lower speeds doesn't work, stay in HV unless you have an extended run over 50 mph. At that point, the ICE is running and piggybacking some charging is effective. If all your driving is in town, just let the car run on the ICE. Have you been paying to charge the battery?
 

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Discussion Starter · #9 ·
Unless you plan to leave the car parked for months without starting it, there is no harm in leaving the HV battery as discharged as it will get by driving it normally. The car reserves a portion of the HV battery pack that it won't use for EV range, and if you start the car while it's below the minimum charge level, it will kick on the ICE to restore it to nominal.

If you don't have access to a charger, using the ICE to charge the HV battery higher than necessary is terrible for fuel economy. That's because you're converting gasoline into mechanical energy, then converting mechanical energy into chemical energy in the battery, then back from chemical energy into electricity to power the traction motors to spin the wheels. This is categorically less efficient than using the ICE to directly drive the wheels, which the Clarity will do when you hit about 62 mph in HV mode.

Like ClarityDave said, when you don't have access to a charger, you should drive your Clarity PHEV as if it were a Toyota Prius. That is, drive it like a conventional gasoline car. Turn it on, drive it, turn it off, fill up the gas tank when needed. This is the most efficient way (in terms of fuel consumption) to travel without access to a charger.

The real use case for the "HV Charge" mode is if you have low battery AND need to travel at significant speed uphill. The ICE in the Clarity doesn't have enough power to propel the vehicle steeply uphill (often with some cargo, if you're going camping or something) while also adding energy to the battery. Extremely steep hills can only be climbed with the traction motors' assistance, so in an ideal world you need the battery to be drained during such climbs, so the battery and the engine can work together to produce more power to the wheels.

If you're traveling on flat or gently hilly terrain (routine up and down oscillations, as are common in the mid-atlantic region), you should never need to use HV Charge.

... Unless you plan to leave it parked, without starting it or driving it, for months. Then it might make sense to turn it on, HV Charge it to 40-50% HV, and shut it down. Turning off the vehicle with a low HV state of charge and leaving it that way for a long time risks a flat battery condition, where you'd be unable to restart the vehicle and need to get it towed to restore a nominal charge to the HV pack.
Thanks for detailed answer. Very helpful. I will start driving in Hybrid Mode until I gain access to the garage with the wall outlet where I can commence charging the Clarity on a regular basis again. Man, can’t wait until September.
I may be the only proponent of HV Charge on this forum. I use it all the time on long trips. I charge to the max, use the electric, repeat. If I know I will be driving getting off the highway, I save some EV range. In your case I do agree that using charge mode at lower speeds doesn't work, stay in HV unless you have an extended run over 50 mph. At that point, the ICE is running and piggybacking some charging is effective. If all your driving is in town, just let the car run on the ICE. Have you been paying to charge the battery?
Unless you plan to leave the car parked for months without starting it, there is no harm in leaving the HV battery as discharged as it will get by driving it normally. The car reserves a portion of the HV battery pack that it won't use for EV range, and if you start the car while it's below the minimum charge level, it will kick on the ICE to restore it to nominal.

If you don't have access to a charger, using the ICE to charge the HV battery higher than necessary is terrible for fuel economy. That's because you're converting gasoline into mechanical energy, then converting mechanical energy into chemical energy in the battery, then back from chemical energy into electricity to power the traction motors to spin the wheels. This is categorically less efficient than using the ICE to directly drive the wheels, which the Clarity will do when you hit about 62 mph in HV mode.

Like ClarityDave said, when you don't have access to a charger, you should drive your Clarity PHEV as if it were a Toyota Prius. That is, drive it like a conventional gasoline car. Turn it on, drive it, turn it off, fill up the gas tank when needed. This is the most efficient way (in terms of fuel consumption) to travel without access to a charger.

The real use case for the "HV Charge" mode is if you have low battery AND need to travel at significant speed uphill. The ICE in the Clarity doesn't have enough power to propel the vehicle steeply uphill (often with some cargo, if you're going camping or something) while also adding energy to the battery. Extremely steep hills can only be climbed with the traction motors' assistance, so in an ideal world you need the battery to be drained during such climbs, so the battery and the engine can work together to produce more power to the wheels.

If you're traveling on flat or gently hilly terrain (routine up and down oscillations, as are common in the mid-atlantic region), you should never need to use HV Charge.

... Unless you plan to leave it parked, without starting it or driving it, for months. Then it might make sense to turn it on, HV Charge it to 40-50% HV, and shut it down. Turning off the vehicle with a low HV state of charge and leaving it that way for a long time risks a flat battery condition, where you'd be unable to restart the vehicle and need to get it towed to restore a nominal charge to the HV pack.
Thank you for the reply. Very helpful.
 

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I may be the only proponent of HV Charge on this forum. I use it all the time on long trips. I charge to the max, use the electric, repeat. If I know I will be driving getting off the highway, I save some EV range. In your case I do agree that using charge mode at lower speeds doesn't work, stay in HV unless you have an extended run over 50 mph. At that point, the ICE is running and piggybacking some charging is effective. If all your driving is in town, just let the car run on the ICE. Have you been paying to charge the battery?
I think you're far from the only one. I use it quite often on road trips. I suspect that while it's running at higher RPM, it's closer to the peak of it's power band, and the ICE can get better mileage. You do have to put up with a lot more engine noise, though.
 
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