Portable car battery charger/conditioner

[turbomoggie]

Hi everyone,

Is there such a thing as a rechargeable battery powered 12v car battery conditioner/charger? I can't seem to find anything online but I might not be searching for the right product.

My car is parked up in the garage over winter but there's no mains power supply. The 12v battery is going flat but I need the battery to maintain it's charge so that the tracker and immobiliser is functioning.

[blueST]

Some sort of solar set up might your best bet. A panel on your roof connected to a decent MPPT charger like are used in caravans and motor homes.

[finlo]

Disconnect the battery and it will stay charged for many months

[turbomoggie]

blueST said:

Some sort of solar set up might your best bet. A panel on your roof connected to a decent MPPT charger like are used in caravans and motor homes.

This would be a great idea but I should've made my first post clearer. The garage is in a basement of some flats.

[turbomoggie]

finlo said:

Disconnect the battery and it will stay charged for many months

I need the battery connected because of the tracker which is a requirement for my car to be insured.

[Shnozz]

I’m yet to find a product that fits the bill. Best I’ve come up with has been a £10 battery cut off.

Interested to see if anyone else has any better solutions.

[blueST]

turbomoggie said:

blueST said:

Some sort of solar set up might your best bet. A panel on your roof connected to a decent MPPT charger like are used in caravans and motor homes.

This would be a great idea but I should've made my first post clearer. The garage is in a basement of some flats.

A big rechargeable torch to shine at the solar panel?

[Baldchap]

turbomoggie said:

finlo said:

Disconnect the battery and it will stay charged for many months

I need the battery connected because of the tracker which is a requirement for my car to be insured.

We've had countless trackers over the years on various things and all have had their own batteries. Are you sure yours doesn't?

[turbomoggie]

Baldchap said:

turbomoggie said:

finlo said:

Disconnect the battery and it will stay charged for many months

I need the battery connected because of the tracker which is a requirement for my car to be insured.

We've had countless trackers over the years on various things and all have had their own batteries. Are you sure yours doesn't?

I think it does. I always presumed this battery would take its power from the 12v battery? Or am I wrong?

[Billy_Rosewood]

Really depends how far you want to go and how long you want it to last...

This and a couple solar panels will probably last a fair while

https://uk.renogy.com/renogy-portable-power-statio...

[turbomoggie]

blueST said:

turbomoggie said:

blueST said:

Some sort of solar set up might your best bet. A panel on your roof connected to a decent MPPT charger like are used in caravans and motor homes.

This would be a great idea but I should've made my first post clearer. The garage is in a basement of some flats.

A big rechargeable torch to shine at the solar panel?

This does sound like a tempting but very inefficient option!

[turbomoggie]

Billy_Rosewood said:

Really depends how far you want to go and how long you want it to last...

This and a couple solar panels will probably last a fair while

https://uk.renogy.com/renogy-portable-power-statio...

Ah this hadn't even crossed my mind. A portable power station that I could then plug something like a ctek in to. Thanks!

[Redline88]

turbomoggie said:

Billy_Rosewood said:

Really depends how far you want to go and how long you want it to last...

This and a couple solar panels will probably last a fair while

https://uk.renogy.com/renogy-portable-power-statio...

Ah this hadn't even crossed my mind. A portable power station that I could then plug something like a ctek in to. Thanks!

That particular model won’t work as it’s only 200wh. Whilst a ctek doesn’t use a lot, the inverter has a parasitic drain meaning that even maintaining, it uses around 18w/hour. So your example would give you just over 10 hours assuming full to start with.

I use a similar pack with a ctek although mine is around 550w/h. Does the job - I just plug it in for the day every couple of weeks to keep it topped up. Some further questions and answers here: https://www.pistonheads.com/gassing/topic.asp?h=0&...

[Robertb]

turbomoggie said:

finlo said:

Disconnect the battery and it will stay charged for many months

I need the battery connected because of the tracker which is a requirement for my car to be insured.

Surely a tracker has its own battery, as otherwise it would be too easy to switch off a tracker.

[Hoofy]

This might be useful:
https://amzn.to/3OtFhnp

You can also link it to a 12v battery as an input that keeps the car's battery full.
https://www.ctek.com/storage/01EE561A527AEE977E76D...

Edited by Hoofy on Monday 5th February 20:13

[CABC]

also an Optimate version:
https://www.amazon.co.uk/OptiMate-TM-500-Motorcycl...
use with a deep cycle leisure battery

[Chubbyross]

What you’re looking for is the Ctek CS Free. It’s a chargeable battery conditioner/recharger. I bought one a couple of years ago. I use it to top up one of my car’s battery over the winter. I usually pop it onto the battery once a week (in a garage with no power supply) and it takes about half an hour to keep the battery topped up. It’s expensive but it does exactly what I want it to do.

https://www.ctek.com/uk/battery-chargers-12v-24v/v...

[donkmeister]

As the solar panel idea is NBG I'd just buy a second battery, keep one at home on a mains powered charger and swap them over periodically.

I have learned from experience that a cheap battery is worse for your use case than a good battery (e.g. Yuasa) of equivalent spec. Seems bizarre as lead acid cells are a centuries-old tech, but that is what I have found.

[Hoofy]

CABC said:

also an Optimate version:
https://www.amazon.co.uk/OptiMate-TM-500-Motorcycl...
use with a deep cycle leisure battery

A stupid question, but why not just have a deep cycle battery connected to the car battery (+ to +, - to -) to keep the car battery topped up, then every week or so, take the deep cycle battery out and recharge it?

Edit: I realise why that's a silly idea. Over time, the battery voltage across the two batteries would drop, while the aim of the Optimizer is to keep the car battery at 12.6v!

Edited by Hoofy on Monday 5th February 22:08

[CABC]

Hoofy said:

A stupid question, but why not just have a deep cycle battery connected to the car battery (+ to +, - to -) to keep the car battery topped up, then every week or so, take the deep cycle battery out and recharge it?

Edit: I realise why that's a silly idea. Over time, the battery voltage across the two batteries would drop, while the aim of the Optimizer is to keep the car battery at 12.6v!

Edited by Hoofy on Monday 5th February 22:08

indeed.
my understanding is that the CTEK Free is great if you have access to the car and can recharge the unit regularly, or just use it weekly. A compact all-in-one unit.
The Optimate with a big deep cycle battery can be left for 3 months, assuming the drain isn't too great. Trackers do significantly increase the drain though.