Trickle, maintenance or float charger? Thanks :)

[SEOLondon]

Hi everybody

I have an R230 2011 SL300. I often go away for 1, 2 or even 5 months through the winter and the car is not in a heated garage, which is not likely to be helpful for the battery. Please tell me:

1. Is it only the back (consumables) battery I need to be worried about (as that is the one I had to change, and that is known to wear out, sometimes too quick)?

2. If I use a solar charger that just plugs into the lighter socket when I'm away, will that actually keep the batteries topped up?

3. Is it safe?

4. Would you recommend any specifications? e.g. mAh?

5. Would you say DON'T buy any of these?

https://www.amazon.co.uk/dp/B000R593JW/?tag=amazon0e9db-21

https://www.amazon.co.uk/dp/B00IB709KU/?tag=amazon0e9db-21

https://www.amazon.co.uk/dp/B07Q2L5WNL/?tag=amazon0e9db-21

https://www.amazon.co.uk/dp/B07QJ1ZNXQ/?tag=amazon0e9db-21

https://www.amazon.co.uk/dp/B002CWPBFS/?tag=amazon0e9db-21

IF YOU HAVE ANY QUESTIONS ABOUT SEO/ digital marketing/ web or software technologies, I will be happy to offer guidance in exchange. Many thanks and be safe

 

[SEOLondon]

Oh.. or this... https://www.amazon.co.uk/gp/product/B07ZJ3WB93/?tag=amazon0e9db-21

Thanks so much all

 

[Smart320]

Used to leave my car in dry storage for 3 months at a time and always used a CTEK , never had a problem as they are designed to be left connected for long periods. They do not shut themselves off if the electric supply is interrupted.

 

[slade1]

i have Ctek and is hot wired to both my cars,excelant bit of kit.
Is the lighter socket switched off when you remove the key?

 

[BTB 500]

As mentioned you want a maintenance charger - they are specifically designed to be connected to the battery for long periods of time. I've kept my R129 SL on one for 13 years, and the battery is now 16 years old As also mentioned some do not resume charging automatically if the mains power is interrupted, which is less than ideal. I use an Accumate because it can be wall-mounted:



AccuMate 6V & 12V Battery Maintenance System

Ctek are another reputable brand.

 

[GeeJayW]

CTEK MXS 5.0
Hard wire the quick connect kit to the battery and tidy/tie it so that it stays put when you're driving the car.
When required, connect the charging unit
Switch on and leave it to get on with managing your battery (it automatically goes through a sequence of modes).
Done.

 

[BTB 500]

Yup many of these chargers come with flyleads that attach permanently to the battery, so you simply plug the charge lead in.

 

[190]

Here's my understanding of solar chargers:

Theoretically unregulated solar chargers can overcharge a battery because the no load voltage can be as high as 18 volts. So when a battery reaches full charge the voltage would continue to rise and damage the battery and or the cars electronics. In practice I've used a solar charger and that wasn't a problem because the alarm current kept the voltage down at a safe level not least because the panel wasn't really big enough. If I was going to use a solar charger again I would choose a larger one but ensure that it had some inbuilt voltage regulation without which I think they are not a practical proposition.

Of the ones listed forget the 1.5 W ones which I had, they are too small. Non of the others mention voltage regulation so you would have to follow that up.

 

[BTB 500]

IIRC the rule of thumb for car-sized batteries is that solar panels of approx. 5W or above should use a charge regulator. Anything smaller will produce such a low maximum current that overcharging won't be an issue. But TBH a proper maintenance charger is by far the best option if there's mains power available.

 

[Wolfie1]

For a solar charger you will need a 50w cell and plugging it into your fag lighter probably wont work as the ignition needs to be on for it to be live.
Make up your own solar charging rig with a solar charge controller. I have this set up on my fun car and its been used for years with no issue, i did experiment with smaller cells but found they didnt give enough juice with the battery still connected to keep it topped up

 

[BTB 500]

Solar charge controllers (certainly the cheaper ones I use for leisure batteries with 25W and 100W panels) are nowhere near as sophisticated as a maintenance charger, and I would be cautious about leaving a car hooked up to one long term.

 

[Wolfie1]

Mine has sat on 1 for years just coming off when i take it out and it has been just fine

 

[magpiemalemerc]

I have the W205 model with a 80ah battery (so I have been told) in the manual it says max charge rate of 5A ?
The ctek MXS 5.0 has been reccomended but on the chance it is out of stock would the NOCO G7200 charger be ok ? bit of a novice... now we have no travel the car is struggling week after week.

 

[SEOLondon]

Hi everybody and thank you so much! Sorry for the late reply. Needed to pay proper attention to this.

@BTB500 - thanks! 16 years - wow! That's what I would like but..


@Everybody - I did not mention that the car is parked on the street so there is nowhere to plug it in, so I am guessing I am forced to (1) use a solar panel that plugs into the lighter socket and (2) I don't know if there's a through-route to pass the cable from the lighter socket to the battery if it needs to be connected, which (3) I am not sure if needs to be done.

@slade1 Do you mean it's a wall socket charger? This is all new to me.

So, @190 and @BTB500 solar charger, significantly >1.5 W, ideally 5W or above, with inbuilt voltage regulation to keep it at a safe level. I have no idea how many Watts would be optimal - please, if you have any thoughts, let me know?

@Wolfie1 - That is way beyond my skill level, but well done! Do you think there's such a thing prebuilt from a reputable manufacturer?

@BTB500 Based on what you said, I want a maintenance charger but a garage is not a practical option sadly. Would you be worried if you were abroad for 3 to 5 months, car parked on the street on a solar charger that was highly rated with 25W to 100W panel?

A million thanks to you all- VERY GRATEFUL FOR YOUR KINDNESS

 

[Deleted member 149005]

I doubt a charger plugged into the accessory socket (cigarette lighter) will work unless the ignition is on

 

[Wolfie1]

Yea there probably will be but probably cost a bit more i would imagine, you would need to connect it onto the battery via crocodile clips

 

[Wolfie1]

Just had a look on ebay search for “50w solar charger” and there is heaps of results, i even think they have come down in price

 

[SEOLondon]

@Wolfie1 , many thanks!

Wish you all the best

 

[190]

I have no idea how many Watts would be optimal - please, if you have any thoughts, let me know?

Basically you need enough watts to replace the loss from the alarm current. The figure I use for that is 35mA which works out at less than 0.5 watts. So why isn't a 1.5 Watt panel enough ? From the experience of my panel it only produced it's rated output at midday in the middle of summer and with the panel perfectly aligned to be perpendicular to the sun. The rest of the time the output could easily be more than a factor of 10 lower. Newer panels may be better as there is now a standard rating system for the type of commercial panel that goes on your roof. If small panels are still as bad as the one I had then I would suggest a starting point for a useful panel of 10 watts when you factor in average daylight hours.