Let's talk chargers for a second..

[Richard Moakes]

A good quality current limiting PSU with a voltage set point of 13.8V connected to the chassis and charging post will keep things happy whilst doing diagnostics.

I have a 30A unit which is fine for diagnostics, but would want 80A or more for programming, but I don’t do that, and if I did, I would borrow a professional unit from a friend https://www.gys.fr/prod-029071-/_/_/en

 

[onefortheroad]

That’s way above my pay grade

You know your onions buddy , don't be coy.

 

[Botus]

Hey guys,

One of my pet peeves is having to run the engine when using STAR.

I am looking at various chargers at the moment and like the looks of the Noco stuff. I think in general I just need a few low current maintenance chargers.. but I am wondering why / if I need to get something higher, like say 10 or 20 amps.

What kind of amperage would I need to keep the battery in good shape during an extended STAR diagnostics session, does anybody know?

Interested to hear what other people are using and experiences with different brands etc? Are the Ring products any good?

Thanks a lot

I was looking for a good battery support unit - I don't want to buy a good one for 900 to 1200 quid, then realise my next car wants 24v / 48v or more than 50 amps as that'll give me a spare I'll never use, cost me lots of money, and upset me - and another consideration for programming you really need to be able to dial the voltage you want the car to sit at - many only push 13.5v, and most manufacturer tools build in deliberate limits on the voltage required, to stop home users doing programming stuff

so I looked further up the food chain at the next level - seems the latest cars need over 120amp support and many want 48v too, but then the one that covers most bases was £2500 plus VAT and there was only one demo to buy across the whole country

so at that rate something a little less came back in to play, and you find a few trinkets for 200 to 300 that pretend they help - but its not enough grunt, but then ones that might leap back into the 500 to 800 arena

I bought one that pushes out 40 amps - but when you read how to use the the battery support feature its NOT to be used with a battery in the circuit ??? keep meaning to get more detail on that - but for now I bung it on AGM push go and hope - the wires nor the clips never get hot and after 2hrs of diagnostic fighting and pushing software in circles - its never charged the car up fully - but it gets there about 10 mins later once the key is out....

running the engine is not the right way - many programming and diagnostic steps must be done with the engine off

Battery Support Unit & Charger 40A | SPBC40 | Sealey

5 Year Guarantee - Automatic 8-stage battery support unit & charger. For charging a variety of EFB (stop/start), GEL, AGM, lead acid and calcium batteries with auto voltage selection.

www.sealey.co.uk

 

[Rockron]

Motorhome and RV electrical installations involve sophisticated battery charging features these days. The Victron range of equipment is thought of as being at the top end of the market. Although the product range is now heavily slanted towards the current! LiFEPo4 hi tech stuff, they still maintain a range of standard high Amp rate chargers for old tech AGM, Flooded Cell etc. batteries. Not cheap.....of course.

 

[LostKiwi]

My neighbour and Dad have had them on cars almost permanently for 3+ years

Same one I use in France on the 129 and Smart. Now coming up 5 or 6 years I've used it.

 

[Wighty]

Same one I use in France on the 129 and Smart. Now coming up 5 or 6 years I've used it.

You were my original inspiration buddy

 

[alexanderfoti]

You really need a power supply.

GYSFlash

OPUS - GYSFlash

www.opusivs-uk.com

A unit like the above would work, and is what we use when flashing cars via OBD, but its overkill and very spendy.

RCBT40T

www.ringautomotive.com

We use one of the above for cars on diagonstics etc. It works well, but I have replaced the leads 2x. This will easily provide power for most cars whilst on STAR.

 

[alexanderfoti]

Have you considered a donor battery via good jump leads?
There might well be circulating currents between the 2 batteries. Connecting a charger of lower ability to the donor would compensate that.

Monitoring the system voltage on Star is easy enough.

12V 24V Smart Automatic Car Battery Charger Pulse Repair Motorcycle LCD Display | eBay

12V 24V 10A Smart. 12V 24V Automatic. Smart Car Battery. 2PCS Smart Car. • Rated output: 12V 8A 24V 4A. 2 Rated output: 24V 4A. • Types of batteries: Most types of lead acid batteries including Calcium, GEL and AGM, Wet,EFB, etc.

www.ebay.co.uk

I've been happy with one of these for a few years, you might find one cheaper.

I bought a batch of these for the workshop, and thought i'd measure their voltage. They pumped out nearly 15.5v most of the time, really overcharging a few battieres. They all went in the bin. Possible I had a bad batch.

RSC806 – 6A Smart Battery Charger & Maintainer

The smart way to charge and maintain car, motorcycle and van batteries.

shop.ringautomotive.com

I have a box of these that I use to keep batteries maintained etc, so far so good!

 

[alexanderfoti]

That’s a charger though and not necessarily enough to keep the car on… the Ctek I linked to will keep a car active at 7a - lot more ££ though…

Most MB's will draw between 18-35 amps with key on engine off. W221's and newer more like 40amps

 

[Conor]

Thanks for the input everybody.

So despite the fact that I don't plan on doing any programming, it looks like MBs still need amps heading into the same ballpark.

So with that in mind I'll continue to slum it by running the engine. I really don't run that many sessions anyway to be honest.

 

[LostKiwi]

I've often thought about attaching an old electric motor (washing machine for example) to an alternator. Heavy and bulky but cheap!

 

[Jason63]

I use one of these for diagnostics, and when I've felt lucky for a bit of programming!

https://cpc.farnell.com/unbranded/i...ench-13-8v-20a/dp/IN06010?st=20a power supply

Connect it up first, the day before, you then start with a full battery and 20A of support. If you can measure the current (most meters won't do it, you need a very low resistance shunt so the voltage drop at 20A is minimal) you can check to see if the PSU is maxed out, if not it'll hold indefinitely.

It's not ideal and 13.8V is a bit low, you really need 14.5V to allow for any voltage drops in the car wiring.

Connect it up with jump leads, if you use normal flex then at 20A you'll get a voltage drop.

 

[Conor]

What do people think of this charger / starter currently in Lidl.

99% of the time, I would be using it as a bench supply / supply during diagnostics (not programming).

How does the starter function of these style products work? I see that it says pulse of 75A for a short period of time.. but isn't the draw for a big cold engine possibly in the hundreds?

I find it hard to get past how limiting a lot of these chargers are.. I feel like it's much better to have knobs where you can control things like voltage / current etc. Perhaps they have gone away from that as their use takes a little more thought and more error prone?

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?

Car Battery Charger & Jump Starter - Lidl Ireland

Car Battery Charger & Jump Starter - Operating voltage: 230V~50Hz Charging currents: 2 / 6 / 17A Start current pulse: approx. 75A / 12V For car and

www.lidl.ie

 

[LostKiwi]

I'd guess that 75A is as it says only a pulse.
Car starting does take several hundred amps, especially on big multicylinder engines.
In the -5° mornings we have right now my OM642 takes everything the (new) battery has to turn over first thing in the morning. It's really sluggish and that battery is rated 720A CCA.

 

[Timeandleisure]

I'd guess that 75A is as it says only a pulse.
Car starting does take several hundred amps, especially on big multicylinder engines.
In the -5° mornings we have right now my OM642 takes everything the (new) battery has to turn over first thing in the morning. It's really sluggish and that battery is rated 720A CCA.

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.

 

[LostKiwi]

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.

I'd definitely take it up with MB if it does it again.
Ours has never failed to start, it's just very slow cranking. That said it always starts inside 5 seconds.
I have the fully charged old battery (original 2011 one) in the shed on standby and a hefty set of jump leads if necessary but not needed yet.

 

[EmilysDad]

It was minus 8 last night here. My ML started up no problem at all earlier

 

[Timeandleisure]

I think I should be on MB’s payroll, the amount of times I have spent in correspondence with them over the last few years… back to the desk it is…

 

[LostKiwi]

@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

 

[Botus]

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 again to clear the snow off the car and drive, after which it started. It has been fine since despite 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.

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