Rav-4 phev charging

[Andy_Rav]

I'm sure this has been covered many times, so apologies if it is a repost... 

I have a Rav4-PHEV, in which we do a lot of local miles in on EV only mode - this ability is fantastic both form a running  costs point of view as well as environmental impact.  My question is should I charge the traction Battery to 100% each time or should it be charged to a reduced capacity?  I have seen some conflicting opinions regarding charging EV vehicles, with some people suggesting that charging to max capacity puts strain on the Battery.  Obviously this would have some impact on the EV range - perhaps by 5 or so miles if it was decided 90% was 'full' but if that is at the detriment of the Battery life then it's a price to pay.

It would be helpful to get a definitive answer form Toyota on this, with some technical backup to justify.

[Flatcoat]

The charging system will sort out managing and conditioning the Battery. The car uses about 80% (aprox 14.5kw) of the Battery capacity (circa 18.5kw) to leave a buffer at both ‘ends’ of the Battery capacity and charge. Toyota have been building hybrids longer than any competitor so I suspect they have the tech sorted. Simply Charge it, drive it, enjoy it. 

[ernieb]

Even when the car is charged to 100% the Battery is actually only charged to around 90+%. this is a guard band that has been built into the car.  My understanding is that it might well be something that can be 'released' as the Battery performance drops with age during scheduled services.

When I placed my original order back ion '21 I looked through loads of posts on various US forums and the above was the conclusion.

The car/MyT app do not allow you to partially charge the tracking Battery, I just charge the car and drive and don't worry.  I charge mine via a granny cable overnight as I don't have access to a 7kW charger. A 7kW charger might well allow you this option, I don't know.

[Oscarmax]

On 9/5/2023 at 1:34 PM, Flatcoat said:

The charging system will sort out managing and conditioning the battery. The car uses about 80% (aprox 14.5kw) of the battery capacity (circa 18.5kw) to leave a buffer at both ‘ends’ of the battery capacity and charge. Toyota have been building hybrids longer than any competitor so I suspect they have the tech sorted. Simply Charge it, drive it, enjoy it. 

My PodPoint app records 15.5 kWh to actually charge the Battery 14.5kWh, I am assuming that is energy losses.

[Flatcoat]

27 minutes ago, Oscarmax said:

My PodPoint app records 15.5 kWh to actually charge the battery 14.5kWh, I am assuming that is energy losses.

Seems a reasonable assumption. 

[Cyker]

Sounds about right, inverter and current heating losses could easily account for that discrepancy. This is why I think 800v charging should have been the norm for EVs - Less energy lost through current heating. (This wouldn't affect the PHEVs since they only do AC charging)

As for the charging to 100%, it's not great for the Battery if it's held at 100% for long periods, but if you're just hitting that overnight then using it the next day, the detrimental effects will be negligible.

If you don't use all of the charge, then it'd be worth lowering it to less than 100%, but if you do then leave it - The Battery is there to be used afterall.

 

[Mike2222]

54 minutes ago, Cyker said:

it's not great for the battery if it's held at 100% for long periods

This is probably the most important self-maintenance point. If leaving it in airport parking for 1-2weeks, then try to ensure it is somewhere 50-80% state of charge, otherwise just home charge to full as often as you want/need. 

 

The chat about charging to 80% max is slightly outdated with modern vehicles, at least when it comes to charging at home (but the Rav can't rapid charge anyway). It's all about temperature management more than anything else. Older BEVs like the 1st gen Nissan leaf had no active Battery temp management. They relied on the flow of air when driving to cool the Battery. However, if you charged it up on a hot day, or left it fully charged out in the sun, the result was notably accelerated Battery decay/degradation. Most modern BEVs, and the Rav phev as well (AFAIK), will use the hvac system (or a standalone system) to bring up battery temp when cold, or to cool it down when too hot, so as to avoid battery stress.

 

It actually can be helpful for a modern battery to be slow charged to full, as it helps with cell balancing (batteries are usually sets of paired cells operating together, and if get unbalanced, then it limits the output/capacity of both). 

[Flatcoat]

The point is the Battery management is now built in. The owner doesn’t need to do anything. You cannot charge the Battery to 100% of actual capacity, it will only charge upto the upper buffer level which will be around 90%. As it reaches that point the charge rate slows so not to damage the Battery. Heating and cooling is also managed by the charging system brain. In warm weather while charging you may hear the cooling fan running. 
 

I will find the article I read about the RAV PHEV charging so all the social media induced misleading information (taken over from pub experts talk) is put to one side.