Leaving for a while - Trickle Battery Charger

[qlaval4]

I was wondering if anyone knew...

I'm leaving for a while, I intend to leave a trickle battery charger on the car.
Will it keep the regular 12v battery charged and the hybrid lithium battery or only the regular 12v battery?

 

[GoZoner5]

(no idea how accurate this is): Grok

 

[qlaval4]

Thank you GoZoner

 

[bluetwo1]

I think the systems are separate so it may only keep the 12 v charged, but that's not a bad thing. Won't the car just charge up its li-on battery upon the next engine start?

 

[Bronco]

Grok (earlier post) found info from the Civic Hybrid manual. However, the 2026 Prelude manual has the same information, which is copied below.

"The High Voltage battery gradually discharges even if the vehicle is not in use. As a result, if your vehicle is parked for an extended period of time, the battery charge level will become low. Extended periods of time at a low state of charge will shorten battery life. To maintain the battery state of charge, drive your vehicle for more than 30 minutes at least once every three months.

Extreme high temperatures can affect the battery life. You can minimize the effects by parking the vehicle in the shade during the summer."

 

[qlaval4]

Grok (earlier post) found info from the Civic Hybrid manual. However, the 2026 Prelude manual has the same information, which is copied below.

"The High Voltage battery gradually discharges even if the vehicle is not in use. As a result, if your vehicle is parked for an extended period of time, the battery charge level will become low. Extended periods of time at a low state of charge will shorten battery life. To maintain the battery state of charge, drive your vehicle for more than 30 minutes at least once every three months.

Extreme high temperatures can affect the battery life. You can minimize the effects by parking the vehicle in the shade during the summer."

Thanks for the confirmation from a reliable source

 

[YYJHondatech]

I was wondering if anyone knew...

I'm leaving for a while, I intend to leave a trickle battery charger on the car.
Will it keep the regular 12v battery charged and the hybrid lithium battery or only the regular 12v battery?

The systems are not integrated with one another when the vehicle is off. It still uses a DCDC converter style system to transfer power from the HV battery to the 12V system.

BUT... if youre going away, just start your car every week for 30 mins with your hondalink app! Problemo solved

 

[qlaval4]

... if youre going away, just start your car every week for 30 mins with your hondalink app! Problemo solved

In a condo not very safe... but the idea was good
Thanks!

 

[BlueTiger]

I have a lot of experience in full hybrid cars: I owned Honda CR-Z, LExus RC300h, Lexus CT200h, Toyota Corolla 2.0, Toyota Yaris 1.5 and I've worked in a Ford dealer.
The problem about the 12V battery is always the same: the hybrid system drains a lot of energy from the 12V battery even when the car is parked. The system is always on in stand by mode to: it manages the main battery and many other stuffs in the car.

So please follow the 3 rules below:
use the car at least every 15 days
if you leave alone the car for more than 15 days use a charge mantainer (15 bucks on amazon/ebay)
keep a small booster inside the trunk (30 bucks on amazon/ebay)

The third rule is mandatory if you live in very cold places or if your 12V battery is not so fresh...

 

[OldCoupeGRGuy1]

I will be using the CTEK battery conditioner. Trading in a Toyota hybrid which has used this for 3 years and stopped any problem with the 12v battery. My GR Yaris lives on the CTEK and the 5 year service gave the battery a 100% result.
I am wondering though how to do this as the Prelude bonnet (hood to many on here) use crockodile clips or buy the 2 foot connector cable with built in fuse i use on the GRY. Red cable to red on battery but CTEK state the black must go on a nut on the body.
Maybe someone can look at their battery and advise if there is a suitable earth near the battery for the black cable. That would make it easy to connect it to. The easy snap connector is then cable tied to something so I can put it on charge say once a month overnight.
Many people are having the problem with flat battery because they are not aware of what blueTiger states. This is what happens:
"The lead plates in a 12V lead-acid battery develop a buildup of lead sulfate crystals, a normal byproduct that occurs as the battery discharges. In a healthy battery, these crystals dissolve back into the electrolyte when recharged, but if the battery sits uncharged, the crystals harden and become permanent."

So, charging it not only keeps it topped up but cleans it. I do it whenever I know it is being stood for a few days when using the other car. Easy to do but very few people know about the problem.