How Long Can a Hybrid Sit?

"Fyoeu" (fyoeu2)
11/15/2019 at 12:11 • Filed to: None

This may be a dumb question, but I’m curious.... So my aunt and uncle are leaving for 6-7 months, and I’m in charge of taking care of their house/starting up their cars every so often...

One of their vehicles is a Lexus RX450h. I’m wondering if it’s possible for the hybrid battery to discharge if it’s not driven for that long?... Especially over the winter.

Has anyone here had issues with a hybrid vehicle sitting for long periods of time?

I’ve read some horror stories of hybrids sitting for too long, causing the hybrid battery to discharge, then having to have the vehicle towed to the dealership to recharge it???

DISCUSSION (18)

ADabOfOppo; Gone Plaid (Instructables Can Be Confusable) > Fyoeu
11/15/2019 at 12:34

You’ll need to drive that for at least 30 minutes once a week ideally. And when it isn’t being driven the 12V battery needs to be on a trickle charger.

I would ask them about simply using it as your weekend car while they are gone just to be sure it won’t be adversely affected by their extended absence.

gmporschenut also a fan of hondas > Fyoeu
11/15/2019 at 12:36

A family member in the military let theirs sit for 7 months and the battery was shot. Even with their spouse starting it once a month for 20 minutes. (But never driving it)

I don’t know about the RX, but I would think it would have to be driven to recharge.

Also will it be garaged or left outside with freezing temps?

Fyoeu > ADabOfOppo; Gone Plaid (Instructables Can Be Confusable)
11/15/2019 at 12:46

hmm, yeah... Guess I’ll have to confirm that with them before they leave. Once a week should be adequate.

Fyoeu > gmporschenut also a fan of hondas
11/15/2019 at 12:47

It will be garaged, but it’s detached and not heated. He asked me to do exactly that - Start it once a month... But it definitely appears that it needs to be driven.

Neil drives a beetle and a fancy beetle > Fyoeu
11/15/2019 at 13:11

Assuming it’s not a plug in; and just thinking about the little I know about batteries and hybrids; most of their charging is done from engine at certain times and braking. So if the idea is to charge the battery up- I think you’d need to drive it around a bit.

gmporschenut also a fan of hondas > Fyoeu
11/15/2019 at 13:24

A bit that is tricky is that all hybrids are a little bit different. On the Lexus site it says that the 450h will send some engine power to recharge the battery, but it doesn’t state if that is a meaningful charge, or a slight trickle. With the point of being a hybrid, it’s goal is reduce fuel use so I can’t see it sending a huge amount while idling.

It may require some testing to see how much Is charged just idling.

j369 > Fyoeu
11/15/2019 at 14:32

Once a month is probably enough. Just use the car for the day. You can’t really “idle” it to charge the HV battery. You need to accelerate the brake and the regeneration will charge the battery.

The HV battery on the rx450h has contactors (high current relays) that physically disconnect the battery when the vehicle is off.

The most likely situation is if you let the car sit too long the 12v battery will discharge and will not be able to close these relays to the HV (hybrid battery) pack and the car won’t turn on. If this happens just throw on a 12v charger and turn the car on.

Under_Score > Fyoeu
11/15/2019 at 14:33

C. Buy the RX450H and sell the Camry. No more worrying for 6-7 months and 6-7 years.

Jason Spears > Fyoeu
11/15/2019 at 14:44

Well according to this: https://www.lexus.com/pdf/service/RXh_WSG.pdf

Every Several Months

If the vehicle is parked for a long time, the hybrid battery will discharge gradually. To keep the hybrid battery in good condition, drive the vehicle at least once every several months for at least 30 minutes or ten miles. If the hybrid battery becomes fully discharged and the vehicle will not start even with a jump-start to the 12-volt battery, contact your Lexus dealership

But based on other responses here, maybe err on the side of caution and don’t wait “several months.” I know household NiMH batteries start to self- discharge as soon as you’re not looking.

Neil drives a beetle and a fancy beetle > gmporschenut also a fan of hondas
11/15/2019 at 14:45

I believe that small amount of nominal engine charge normally happens at steady state highway driving when you’re fuel economy is at its best. But it does vary by car. All that to say, it’s probably way more efficient to drive around in a neighborhood with lots of stopping for brake regen .

dan3196 > Fyoeu
11/15/2019 at 16:20

As a product specialist for Lexus for several years as well as a battery specialist I can assure you that you must have these on a tender. unbenown to most people the Lexus Hrbrid has 2 batteries. The starting AGM absobed glass matt battery and the hybrid NiMH nickel metal hydride. The important thing is to make sure electrons are always flowing.This is done by putting a tender on the starting battery and driving the vehicle at least 30 minutes every two weeks at least. Running it is not good enough you must actually drive it at hwy speeds. If the starting battery sits too long with no electical activity you risk sulfating the batteries and greatly reducing the life and the effectiveness of the battery voltage and cranking amps.

Pervia > Fyoeu
11/15/2019 at 16:34

From the RX400h’s (not exactly the same as the RX450h, but similar) Hybrid Overview manual:

“For parking longer than about 30 days, charging of the 12-volt battery may be required. See your dealership for details. To keep the hybrid battery in good condition, drive the vehicle at least once every several months for at least 30 minutes or ten miles. If the hybrid battery becomes fully discharged and the vehicle will not start, even with a jump start to the 12-volt battery, contact your Lexus dealership.”

Reference: https://www.lexus.com/pdf/models/rxh_driving_performance_guide.pdf

Dr. Zoidberg - RIP Oppo > Fyoeu
11/15/2019 at 18:03

You should consider an RX350 instead.

GLiddy > Fyoeu
11/16/2019 at 00:22

I had an RX400h, and the longest I let it sit was for 3 weeks so probably not a good data point. The battery will charge to a full charge by just idling it, but like any car its probably better to take it for a little drive. In my time of hybrid ownership, the oddest thing I found was that the car wouldn’t start if the 12V battery was low despite having a good charge on the traction battery.

The biggest problem is that if there is a charge on the battery, if you do just turn it on in the garage, it may sit with the engine off (no load) and drain the traction battery until it falls to a low charge level and let the ICE engine start. This process would take awhile. Take it on a drive.

Fyoeu > Dr. Zoidberg - RIP Oppo
11/16/2019 at 00:30

If Lexus makes an RX-F.... I will consider it.

Fyoeu > Under_Score
11/16/2019 at 00:34

Hah! oh I wish.... I would LOVE to go from a worn out 95 Camry to a RX450h....

Fyoeu > dan3196
11/16/2019 at 00:35

Good to know!! Thank you. I guess I’ll swap cars and drive the RX450h on weekends.

Steve in Manhattan > Fyoeu
11/16/2019 at 19:00

Wow - you got a real expert.