Let's talk chargers for a second..

[Jason63]

@Conor

This do?
12V 100A 1200W DC Switching Power supply Adapter PSU AC-DC 12Volt Industrial Transformer Converter 0-80/50amps LED drive Lamp Meter Semiconductor Motor Pump Winch Stereos Amplifier Fan SMPS 110V/220V https://amzn.eu/d/gEUxZl1

Something like this would be great but this one only goes up to 12.6V. You ideally need 14.50V although 13.8V would probably do, and if you read the comments they do a 13.8V version.

I used a 60A PSU that looked a lot like this to do some programming in the past.

 

[supernoodle]

Can these things generally be used as a bench 12v supply or are they kind of unsuitable for that as the charger tries to do smarts based on what the connected item is drawing etc?

I would really like a switchable PSU for my work bench.. but perhaps it's better off to buy that separately? As chargers and bench supplies are ultimately two different products?

Not sure what sort of work you're going to be doing on the bench, but doubt you'll need anything that big. I do a lot of work with modules on a bench, most of the time they are only drawing a couple of amps. At switch on there can be an inrush current of 10A, but even smaller bench PSUs cope as they have some capacitance in the output stage.

If you're connecting up some inductive loads too they can be quite power hungry, but it depends what you are intending to do.

I certainly would recommend a proper bench PSU that has variable current limitation and current draw. Both useful for fault finding.

 

[Jason63]

That's really interesting... We didn't have much snow but enough to settle. The coldest it got was -1.0 degrees. I didn't drive the next day but the day after. The outside temperature was a nice one degree and the car only had a thin layer of snow on the boot and rear panoramic section of the roof. The bonnet and windscreen were clear, but to my dismay, the car would not start even after several attempts. using the time until I tried agin to clear the snow off the car and drive, after which it started. It has been fine since despita colder conditions. My previous car of 17 years never once failed to start even in worse conditions. Is this unusual for a car that's only 20 months old?

Should I take it up with MB?

I also had the dreaded radar inoperative, which was a recall condition for some models manufactured at certain times, but outside my time of model and manufacturer.

That really isn't acceptable.....unless it's caused by your usage pattern. I know BMW diagnostics will extract a usage profile for the last 30 days allowing the dealer to state that it's basically your fault for using the car incorrectly! Loads of short journeys will take more from the battery than gets put back in.

A fully charged battery in a modern car should start it down to at least -20C.

 

[Timeandleisure]

how often are you using the car ? in these extreme temps 2 weeks will be enough to upset most modern cars... they eat power all the time with the key out
and people need to clean the road filth off the front of modern cars ADAS

Daily round trips on the motorway of approx 70 miles interdispersed with small local amounts appox, 10 miles, since mid November. However, its usual habitat Has been the motorway before then too...

 

[Timeandleisure]

That really isn't acceptable.....unless it's caused by your usage pattern. I know BMW diagnostics will extract a usage profile for the last 30 days allowing the dealer to state that it's basically your fault for using the car incorrectly! Loads of short journeys will take more from the battery than gets put back in.

A fully charged battery in a modern car should start it down to at least -20C.

My journeys are usually on the motorways so it seems that I need to get a letter off to MB customer service...

 

[Botus]

10 miles in a month? that's not a letter thats to be expected?

 

[Timeandleisure]

10 miles in a month? that's not a letter thats to be expected?

.... 10 miles in addition to the daily 70 miles... so sometimes up to 80 miles a day......

 

[Timeandleisure]

10 miles in a month? that's not a letter thats to be expected?

Even though and perhaps I don't know enough... I would expect a of only battery 20 months old to be able to start a car irrespective of low mileage... The mileage after 4 years on my mum's daily drive MB was 2,500 miles and never had an issue with the battery...

My car was shipped in Dec 2020 and first sold in Feb 2021...

 

[Botus]

cold weather knocks the hell out of a battery, a modern car car will take at least 1/3rd of its capacity just doing nothing locked sitting on the drive in 3 weeks (in the summer) and and a week and half in the winter, then you start it with the lights and wipers going, drive for 3 miles and take another 10% out and only put 5% back in

cars like being driven everyday - leave a 2 week gap and they give more issues... in this weather, 3 weeks and the battery is getting damaged, regardless if it starts or not

 

[Timeandleisure]

cold weather knocks the hell out of a battery, a modern car car will take at least 1/3rd of its capacity just doing nothing locked sitting on the drive in 3 weeks (in the summer) and and a week and half in the winter, then you start it with the lights and wipers going, drive for 3 miles and take another 10% out and only put 5% back in

cars like being driven everyday - leave a 2 week gap and they give more issues... in this weather, 3 weeks and the battery is getting damaged, regardless if it starts or not

Makes sense.... just wondering what's up with mine... its certainly hasn't been sitting around... I wouldn't call 70 miles a day sitting around... It was just the one day before that I didn't drive it... strange... It didn't even sound as if it was trying to start... just silence but all the dash lights did light up....I think there is a glitch in the software somewhere.... After all it has just has an update and with my MB history, it always involves going back to sort out a niggle or two....

 

[Botus]

16 years ago a merc battery would do 10 years all day long and 14 if pampered - in today's world they are on their last legs at 2.5 years, with the aim to be dead 23 seconds after the warranty ended

 

[Timeandleisure]

16 years ago a merc battery would do 10 years all day long and 14 if pampered - in today's world they are on their last legs at 2.5 years, with the aim to be dead 23 seconds after the warranty ended

true say....you make me miss my car...

 

[Blobcat]

Makes sense.... just wondering what's up with mine... its certainly hasn't been sitting around... I wouldn't call 70 miles a day sitting around... It was just the one day before that I didn't drive it... strange... It didn't even sound as if it was trying to start... just silence but all the dash lights did light up....I think there is a glitch in the software somewhere.... After all it has just has an update and with my MB history, it always involves going back to sort out a niggle or two....

I’m guessing yours is an AGM battery and that it’s probably dry

 

[Timeandleisure]

I’m guessing yours is an AGM battery and that it’s probably dry

Will check!

 

[Timeandleisure]

Apologies for hijacking the thread but just for completion... the manual does mention 'battery discharging from using devices connected to the diagnostics connection, check battery, if low charge battery by driving a considerable distance'. I updated to FU3 mid October where the car was running for 6:30 hrs. MB did not run it anywhere and I drove approx. 50 miles every day after for three days... When driving since then, the battery has shown to be charging fine....
Wonder if the install contributed to any of this... Hopefully update this on another thread when I hear back from MB.

 

[Botus]

strange abilities of these more durable AGM batteries

the point Blobcat makes is the battery might be in OK condition - but unable to take or retain charge because the damp soggy tissue paper between the plates of an AGM battery have dried out -

to ensure you don't know this and keep you buying batteries at £350 a pop - they trained the teachers at school to tell you never to dare look inside, and write horror stories the world with end for all if you ever unscrew the little black caps under the sticker - let alone risk destroying the universe by attempting to top the battery up with conventional distilled water

good luck trying to check - 4 are light bonded and 2 of the 6 are now MEGA BONDED in to stop the knowledgeable ones maintaining their car correctly. My father's stripped the dam thread on two BUT I got then out with a lot of extra persuasion - not much to lose - its bin material or unscrew them.... the top up should just enough to swell the tissue, then recheck after 24hrs - might take 3 months for the battery to realise and get back close to original capacity

BT dongles in the OBD2 port come in various guises - the clever one's go to sleep and don't stay live forever

 

[rorywquin]

Even though and perhaps I don't know enough... I would expect a of only battery 20 months old to be able to start a car irrespective of low mileage... The mileage after 4 years on my mum's daily drive MB was 2,500 miles and never had an issue with the battery...

My car was shipped in Dec 2020 and first sold in Feb 2021...

My wife’s MB is now going on 8 years old - low mileage ~40k and still on the same battery.

 

[rorywquin]

strange abilities of these more durable AGM batteries

the point Blobcat makes is the battery might be in OK condition - but unable to take or retain charge because the damp soggy tissue paper between the plates of an AGM battery have dried out -

to ensure you don't know this and keep you buying batteries at £350 a pop - they trained the teachers at school to tell you never to dare look inside, and write horror stories the world with end for all if you ever unscrew the little black caps under the sticker - let alone risk destroying the universe by attempting to top the battery up with conventional distilled water

good luck trying to check - 4 are light bonded and 2 of the 6 are now MEGA BONDED in to stop the knowledgeable ones maintaining their car correctly. My father's stripped the dam thread on two BUT I got then out with a lot of extra persuasion - not much to lose - its bin material or unscrew them.... the top up should just enough to swell the tissue, then recheck after 24hrs - might take 3 months for the battery to realise and get back close to original capacity

BT dongles in the OBD2 port come in various guises - the clever one's go to sleep and don't stay live forever

AGM - G = glass as in fibreglass.

 

[Botus]

AGM - G = glass as in fibreglass.

yes but they become ADM absolutely dry matting

 

[rorywquin]

yes but they become ADM absolutely dry matting

Don’t know what brand is in my wife’s car but as mentioned still fine (8years old) . I had to replace the Varta in my SL a year ago (4 years old but very low mileage).