How to trickle charge without electricity

[MCR827]

I’ve just lost the use of my garage - boo. However I have found a new one - hooray. However it doesn’t have electricity - boo. So how am I going to trickle charge my old car over the winter months? What I thought is that I could connect my trickle charger to a DC inverter and then connect that to a 12v battery.

Will this work and if so, what kind of battery? A ‘normal’ car battery is designed to deliver a big charge on start up and not for long use, so do I need a deep cell battery which, as far as I am aware, gives a good constant output over a period of time?

Anyone recommend a particular battery that might suit?

[Mr MXT]

Solar panel?

[normalbloke]

Take the battery home.

[Super Sonic]

I was also going to say solar panel but I imagine it's pretty dark in the garage, can you take the battery home and keep it charged there?

[Mr MXT]

Super Sonic said:

I was also going to say solar panel but I imagine it's pretty dark in the garage, can you take the battery home and keep it charged there?

I was thinking on the roof and extend the cables through. That’s how I keep the leisure battery on my trailer (for internal lights, winch, heater etc) conditioned.

[Riley Blue]

I have the same problem. Sometimes I disconnect the battery and bring it home to charge but more often than not I leave it in the car (it's there this winter) and guess what - after spending October to April in a cold garage it starts!

If it doesn't I clip on my battery booster pack and away it goes. That though is on a 60 year old car that doesn't have any electronic wizardry that needs constant pampering.

[Krikkit]

Fit an isolation switch and just turn the whole show off, imho.

[MCR827]

Thanks for the responses - yes I could take it home but it is awkward to get at and a bit of a pain to get out and lug home. I could also just start it every couple of weeks but can’t drive it anywhere as it is SORN, so I was trying to think of another way round it, hence the inverter potential. I don’t want to risk running the battery down as I have just destroyed the last battery by letting it go flat a couple of times and some cells went awol.

Not too sure a solar charger would work bearing in mind it is over the winter months - even my solar lights in the garden don’t work over winter so I doubt I’d get much charge out of one.

[braddo]

MCR827 said:

... So how am I going to trickle charge my old car over the winter months?

What car is it? Does it definitely need a trickle charge or can you simply disconnect the battery?

Buying a lithium-battery jump starter is really useful too as they are tiny (the size of a bible) so very easy to bring with you in case the battery goes flat.

[stuckmojo]

Krikkit said:

Fit an isolation switch and just turn the whole show off, imho.

That's what I do.

[Hoofy]

Assuming you can't just disconnect the battery (because the car electronics would st itself), and you can't put a decent solar panel on the roof (it'd be enough to keep things topped up if it's 20W+), then trickle charging from a deep cycle battery via a CTEK CS FREE https://amzn.to/3YYrauH (cheapest ever price! I paid £280 for it! Might buy another!) is your only option.

If you just connect the deep cycle battery to the car battery, it would slowly drain both batteries that balances out as it continues to drop, then when you go to take the deep cycle battery and recharge that, it would average out with the car battery eg (10v + 12.6v) /2 so it just extends the trashing of the car battery by a couple of weeks.

Using the CS Free means the deep cycle battery drops whilst maintaining the car battery at full voltage, just like it's being trickle charged from the mains.

Edited by Hoofy on Thursday 21st November 11:07

[andy43]

I’ve got a ride on mower with a 12v battery like a small car. Used to die every winter to the point of needing replacing if I didn’t remove it and keep it trickle charged in the garage but now I’ve got a little 12” x 3” solar panel propped up behind the north facing shed window that has kept the same battery going for a good five years despite getting covered in cobwebs. Search for 12v solar on Amazon or similar - it even came with crocodile clips.
Just attaching a little panel to the soffit or somewhere should be all you need rather than drilling holes in the roof.

ETA this £22 one is exactly what I have https://www.amazon.co.uk/Waterproof-Automotive-Mot...

[CABC]

Hoofy said:

Assuming you can't just disconnect the battery (because the car electronics would st itself), and you can't put a decent solar panel on the roof (it'd be enough to keep things topped up if it's 20W+), then trickle charging from a deep cycle battery via a CTEK CS FREE https://amzn.to/3YYrauH (cheapest ever price! I paid £280 for it! Might buy another!) is your only option.

If you just connect the deep cycle battery to the car battery, it would slowly drain both batteries that balances out as it continues to drop, then when you go to take the deep cycle battery and recharge that, it would average out with the car battery eg (10v + 12.6v) /2 so it just extends the trashing of the car battery by a couple of weeks.

Using the CS Free means the deep cycle battery drops whilst maintaining the car battery at full voltage, just like it's being trickle charged from the mains.

Edited by Hoofy on Thursday 21st November 11:07

yes, we're now in an era where many cars don't like boat switches.
the Optimate DC is the same principle but much cheaper. the CS Free is pricey and doing quite a few things, which op may not need.
https://www.optimate.co.uk/battery-chargers/optima...

[so called]

stuckmojo said:

Krikkit said:

Fit an isolation switch and just turn the whole show off, imho.

That's what I do.

I have a remote isolation contactor, called a Battery Brain, on my TVR.
Stopped me getting flat batteries when leaving in airport car parks.

[aeropilot]

Mr MXT said:

Super Sonic said:

I was also going to say solar panel but I imagine it's pretty dark in the garage, can you take the battery home and keep it charged there?

I was thinking on the roof and extend the cables through. That’s how I keep the leisure battery on my trailer (for internal lights, winch, heater etc) conditioned.

I had the same problem 10+ years ago with my Harley because of the drain from the factory alarm system, and I got a solar panel trickle charger and popped it on the roof and fed the cable through, but the panel wasn't really big enough to over come the drain from the alarm......(was a standard caravan/camper one) and so I ended up just removing the battery and leaving it on a charger at home.
Was a PITA though with the alarm when connecting the battery back again, and removing as had to dismantle the seat completely and I didn't like leaving bike over winter with no alarm function, but was only way.

If its old car with no alarm etc., one of the bigger solar panels now available should be OK I would have thought...?
But, if easy to remove battery, I'd just do that and leave on charge at home.

[drmotorsport]

Petrol generator?

[shtu]

drmotorsport said:

Petrol generator?

Outputting 240v
With a battery charger plugged in.
The MC Escher of battery charging.

The sheer waste of some suggestions gives me Forrest Whittaker eye. The only two cheap and practical soutions are a solar panel, or take the battery off and store\charge elsewhere.

Spending £300 on a fancy charger? Nah. Odds are you could replace the battery a few times for a similar budget, and have a brand-new batttery with warranty each time.

Edited by shtu on Thursday 21st November 13:06

[Olivergt]

There is an isolation switch that you can fit inline with your battery and is operated from a remote control, so basically you fit it once and then use the remote to isolate the battery.

This is handy if the battery is in an awkward place as you only need to fit once.

I'll see if I can dig out a link.


Here you go:

https://youtu.be/rSCB5jCpOuM?si=SaP8t-Mm_BoJnDyS

And I think this is the link to the device.

https://amzn.to/40TB5EC

Edited by Olivergt on Thursday 21st November 13:38

[shedweller]

I have this issue...

My solution is one of these https://www.cityplumbing.co.uk/p/longi-solar-hi-mo...

With a victron 'smart solar' charge controller, the smart controller allows you to set the battery charge/float/absorbsion voltages and loads of parameters via the app...

Works really well, infact it has exceeded expectations so far

[vikingaero]

Just reading the original post shouted solar as the answer, or a hamster wheel for the mice to keep it topped up.