Battery

[bob38]

I bought a trickle charger to connect to my Yaris Cross as I am going to be away for 4 months but the manufacturer says the Battery should be disconnected for safety! Any ideas? Toyota says do not disconnect but is it safe to keep trickle charger on for 4 months? 

[Mooly]

Four months is a long time. What I have written below are just my thoughts based on my experience in electronics rather than definitive answers.

All chargers are not created equal (and don't ask me what I would recommend because I haven't bought one in over 40 years) but I would not be happy leaving a Battery on charge that length of time unattended. What if the charger failed or delivered to high a voltage etc. 

Without knowing what to recommend I would suggest you first look to chargers specifically made and marketed for vehicles that are laid up over the winter (for several months in other words). I suspect an older style 'linear' type power supply with mains transformer and regulator would be more trustworthy than a modern cheaper SMPS (switching type) but this is something I haven't researched. You need little current capability for this function, just a few hundred milliamps at most... even for a Toyota with all these 12 volt Battery issues 🙂    

If the 'maintenance charge' voltage is to high it will damage the Battery. You possibly need a charger that can cycle on and off in response to the terminal voltage of the battery rather than a 24/7 charge regime.

Classic cars that off road for long periods, they might be the people to ask.

Is there any real reason why the battery can not be isolated for this length of time. Would the hybrid battery suffer?

Lets see what the others think.

  

   

[Corolly Poly]

Now I am old I am a fair weather biker. I regularly leave my bike connected to a trickle charger (Optimate) for 4 months or so over winter.

What I have learnt is that to keep it on solidly for those 4 months reduces Battery life considerably. I was replacing them every couple of years.

What I do now is use a smartplug that only powers up the charger for 15-20 minutes a week. The bike always fires up and I haven't replaced the Battery in almost 4 years.

[Mooly]

14 hours ago, Corolly Poly said:

What I do now is use a smartplug that only powers up the charger for 15-20 minutes a week. The bike always fires up and I haven't replaced the battery in almost 4 years.

That is perfect for your situation and probably could be adapted here.

Perhaps something like that but with a bit more on time per week (because we know the hybrids drain the Battery 24/7) would be the answer. 30 minutes a day? or perhaps a couple of hours every 3 or 4 days or a random mix.

 

[Corolly Poly]

48 minutes ago, Mooly said:

That is perfect for your situation and probably could be adapted here.

Perhaps something like that but with a bit more on time per week (because we know the hybrids drain the battery 24/7) would be the answer. 30 minutes a day? or perhaps a couple of hours every 3 or 4 days or a random mix.

 

Yes.  You would probably need to experiment but 15-20 a week is good for a bike Battery with minimal sources of drain.

Decent smartplugs (tplink) can be had for less than a tenner. 

[TonyHSD]

There is a fuse in the fuse box under bonnet, just take this out, lock the car manually with the build in key and go on your trip.
When you come back , insert the fuse, start the car and leave it ON for 40-60 min which is enough time for the inverter to recharge your Battery.
If the car is dead , recharge with smart charger and see in a week time will it hold a charge, if not replace with new Battery. 
Here on the video around 03:40. 

Tyres can be pumped up too and if your car is parked outside I strongly recommend to anyone buy or make yourself wheel covers. These will save you a lots of money because the hybrids biggest issues are the brakes and then the batteries. Keep your brake discs corrosion free and they will last you long time. , perhaps lifetime. Avoid parking under trees and on a busy high street or main roads, that’s all. 

[Mooly]

2 hours ago, Corolly Poly said:

Decent smartplugs (tplink) can be had for less than a tenner. 

Indeed so👍

Or even just a simple timer:

One thing I thought of... trust me (lol) is that any charger used like this should not drain the Battery when the power is off. I suspect any that do would be in the sub milliamp region anyway but it might be worth checking with a meter in series to make sure no current flows in an off state.  

[ColinB]

On 11/15/2024 at 8:29 PM, Corolly Poly said:

Now I am old I am a fair weather biker. I regularly leave my bike connected to a trickle charger (Optimate) for 4 months or so over winter.

What I have learnt is that to keep it on solidly for those 4 months reduces battery life considerably. I was replacing them every couple of years.

What I do now is use a smartplug that only powers up the charger for 15-20 minutes a week. The bike always fires up and I haven't replaced the battery in almost 4 years.

I use an Optimate on my motorcycle as well, it also is not used over winter so is left connected for long periods of time. I can't say that I noticed any adverse affect on the Battery, the original lasted over 8 years used like this. Saying that I've also considered using a timer on the charger, but haven't felt the need to yet, although the bike is sadly seeing less and less use nowadays. 

[Corolly Poly]

On 11/17/2024 at 7:43 AM, ColinB said:

I use an Optimate on my motorcycle as well, it also is not used over winter so is left connected for long periods of time. I can't say that I noticed any adverse affect on the battery, the original lasted over 8 years used like this. Saying that I've also considered using a timer on the charger, but haven't felt the need to yet, although the bike is sadly seeing less and less use nowadays. 

I expect Optimates have moved on. Mine is a II I think. But I think I would still go for timed charges even if I used the CTEK I bought for the car.