Lexus CT200h Hybrid - Service Battery Problems

snaithg

I own a Lexus CT200h Hybrid which rarely gets used now and frequently goes a few weeks between runs. Due to the fact that the 12volt service battery continues to power various electrical systems within the car, the 12volt battery is prone to lose its charge over time, eventually resulting in the car refusing to start. At this point we usually resort to using a standby 12volt battery, which is kept fully charged, to "Jump Start" the car followed by a long run to restore sufficient energy into the 12volt battery to keep things going again, at least until the next period of non use.

I was told by a garage mechanic once that there was a way to "Soft Charge" the low voltage battery to keep it at full charge thus ensuring the car will always start when needed. I didn't pursue this at the time but I would like to know whether any of you forum members know of such a "simple" method to keep the car battery permanently "topped up"?

Thanks in anticipation,
Graham.

IronGiant

You probably want a smart charger with a maintenance mode for long term connection.  This is a budget one:  https://www.amazon.co.uk/MOTOPOWER-Maintainer-Motorcycles-Powersports-Batteries/dp/B078GPM2QQ/ref=sr_1_10?keywords=smart charger&qid=1572888448&smid=A368O7OVZP75AQ&sr=8-10  This is the one I have: CTEK MXS 5.0 Fully Automatic Battery Charger (Charges, Maintains and Reconditions Car and Motorcycle Batteries) 12V, 5 Amp - UK Plug: Amazon.co.uk: Car & Motorbike

snaithg

Thanks IronGiant, I'll take a look at the Smart Chargers. Apparently the chargers need to be compatible with Stop/Go cars and Gel Batteries, both of which apply to my car I believe.

Graham.

un1eash

All the current ctex trickle chargers are compatible with stop/start AGM batteries.
I've got the 3.8 with comfort indicator cable for easy connection.

redaprilia

ctek mxs 5.0 or 10 for cars , you can select agm battery type from the front panel BUT op have you thought that the original battery is simply "time expired" . AGM battery tend to have a shorter service life that conventional batteries which can often go on for 10 to 12 years.