[condor]

W124 posted for sale in TBHP Classifieds:


http://classifieds.team-bhp.com/buy-.../-Other-.html/

I kind of remember seeing this ad earlier too ..

[Persian]

Hey guys,
I own a W212 E350. Am looking out for 124 to buy. Pls msg me any leads on good one.

[CLYDE]

Hello everybody,

The battery on my W124 is getting on in years (an Exide fitted prior to my getting the car in December 2016) and since I run her only over the weekends to keep the fluids going, I need to bench-charge the battery prior to an outing. I need to know if it is OK to connect the charger WITHOUT disconnecting the car's wiring from the battery terminals. I used to bench-charge my TATA Indigo without isolating the battery, but modern-day cars require the battery to be disconnected prior to bench-charging, hence this query.

Hope someone can help. Thanks in advance.

CLYDE

[Jeroen]

Originally Posted by CLYDE

The battery on my W124 is getting on in years (an Exide fitted prior to my getting the car in December 2016) and since I run her only over the weekends to keep the fluids going, I need to bench-charge the battery prior to an outing. I need to know if it is OK to connect the charger WITHOUT disconnecting the car's wiring from the battery terminals. I used to bench-charge my TATA Indigo without isolating the battery, but modern-day cars require the battery to be disconnected prior to bench-charging, hence this query.

When using trickle chargers it is no problem using it whilst the battery is still connected. But for normal/fast chargers it is a different story all together. You need to disconnect the battery prior to using such a charger. At least that is conventional wisdom and you find lots of battery charger websites promoting this.

With a modern charger and modern batteries I do not see any reason to disconnect the battery, even on modern cars. But this is a case of better safe than sorry. All my classic cars are on a permanent trickle charger, with the battery still connected. Would I hook up a high power battery charger to a battery still connected. Either on my modern cars or classic cars? Probably not. I just do not like the idea of several hours of many amps being poured into a chemical box, that is sitting in my car and hooked up to my car electronics.

I have said this many times, when in doubt check your car owners manual first before asking the internet. If your particular car has a problem with charging whilst the battery is still connected it will be listed in your owners manuals. I am pretty sure there are some cars/manuals out there with such an exact warning!

Jeroen

[CLYDE]

Thanks Jeroen. I think I should have been a little clearer! I am just giving my ageing battery a refresher charge for two hours only (once a week) on the night prior to taking my W124 out for a run. I never leave battery chargers connected, whatever may be the battery application because however good the manufacturer may claim the charger to be, there is the risk of overcharging.

I disconnected the negative terminal when I gave the battery a refresher charge yesterday, but this repeated connecting-disconnecting every week doesn't seem like a good idea, hence my query. My charger gives a steady 14V output (checked on a multimeter).

If I can leave both battery terminals connected while giving the unit a refresher charge, there will be nothing like it.

By the way, (correct me if I'm wrong) no operations manual of any car I've owned so far talks about recharging of batteries, on or off the vehicle.

[Viraat13]

Originally Posted by CLYDE

Thanks Jeroen. I think I should have been a little clearer! I am just giving my ageing battery a refresher charge for two hours only (once a week) on the night prior to taking my W124 out for a run. I never leave battery chargers connected, whatever may be the battery application because however good the manufacturer may claim the charger to be, there is the risk of overcharging.

I disconnected the negative terminal when I gave the battery a refresher charge yesterday, but this repeated connecting-disconnecting every week doesn't seem like a good idea, hence my query. My charger gives a steady 14V output (checked on a multimeter).

14V would equal a jump start, which is something the owners manual specifically mentions not to do. The OVP relay is at risk.

I would suggest that you invest in a new battery, and also investigate what's draining your battery. My E220 used to start up after weeks, and sometimes after months of not being driven.

If the battery is healthy, and you're just worried about not being able to start the car after a long gap, invest in a quick-release battery terminal or a "chor switch".

[Jeroen]

Originally Posted by CLYDE

By the way, (correct me if I'm wrong) no operations manual of any car I've owned so far talks about recharging of batteries, on or off the vehicle.

Some Honda’s spring to mind. There might be others too.

Rather than to have to go through the hassle of disconnecting the battery cable get yourself one of these battery clamps with a disconnect knob:



Jeroen

[CLYDE]

Thanks, Jeroen. I've never seen one of these before. I hope I can get it in Mysore, India, or anywhere else in the country!

[kevinephraim]

Any link to the w124 whatsapp group that is referred a few times to in this thread?

[Viraat13]

Originally Posted by CLYDE

Thanks, Jeroen. I've never seen one of these before. I hope I can get it in Mysore, India, or anywhere else in the country!

You'll find it on AliExpress or maybe even Amazon.

Originally Posted by kevinephraim

Any link to the w124 whatsapp group that is referred a few times to in this thread?

PM your number. I'll add you.

[CLYDE]

Hello Jeroen,

Regarding the battery cutout switch, I located one (Leoie Car Motorcycle Battery Terminal Link Quick Cut-Off Switch) on Amazon India for Rs. 333 or so. Three questions :

Is Leoie a reliable brand?

Should I install the cut-off switch on the positive terminal of the battery? I saw videos where owners of American cars were fitting it on the NEGATIVE terminal, both as a theft deterrent as well as a cut-off switch for when electrical repairs needed to be carried out.

When charging, will it be necessary to completely remove the turn-out knob and disconnect the removable part of the cut-off switch from the battery terminal, or will it just suffice to unscrew the knob 'till the lights go out'?

I only hope the length of the unit is not a deterrent : my W124's battery terminals are towards the firewall of the car, unlike other cars which have the terminals towards the front.

Do let me have your views on this. Thanks a lot.

CLYDE

[Jeroen]

Originally Posted by CLYDE

Regarding the battery cutout switch, I located one (Leoie Car Motorcycle Battery Terminal Link Quick Cut-Off Switch) on Amazon India for Rs. 333 or so. Three questions :

Is Leoie a reliable brand?

I quickly checked my Jaguar and it has an identical looking one. It is not branded, but it looks identical. It is a very simple device.

Originally Posted by CLYDE

Should I install the cut-off switch on the positive terminal of the battery? I saw videos where owners of American cars were fitting it on the NEGATIVE terminal, both as a theft deterrent as well as a cut-off switch for when electrical repairs needed to be carried out.

It goes on the negative terminal. On most batteries I am familiar with, the positive tends to be a larger diameter. So you can not even get it on, if you tried. Negative is the safest of course, just as it is always recommended for doing (electrical) repairs.

Originally Posted by CLYDE

When charging, will it be necessary to completely remove the turn-out knob and disconnect the removable part of the cut-off switch from the battery terminal, or will it just suffice to unscrew the knob 'till the lights go out'?

No, just loosening it is sufficient. For anti-theft, obviously you take it out completely

Notice, the unit I have installed on my Mercedes W123 has a zener diode (the little red light) installed across it. What that does, with the turn out knob loosened or removed, a small current will still go towards the cars electrical systems. So it means my radio stays programmed and the electrical clock stays at the correct time. Very convenient. Anything trying to draw a larger current (e.g. starting) and the zener will just pop.

https://www.youtube.com/watch?v=EtLGUgkqneM

Originally Posted by CLYDE

I only hope the length of the unit is not a deterrent : my W124's battery terminals are towards the firewall of the car, unlike other cars which have the terminals towards the front.

Yes, it can be a bit fiddly in some cars. You might have to experiment a bit, maybe even re-orientate the battery.

Good luck, show us some images when done!

Jeroen

[Sutripta]

Originally Posted by Jeroen

Notice, the unit I have installed on my Mercedes W123 has a zener diode (the little red light) installed across it.

Zener?

Regards
Sutripta

[Jeroen]

Originally Posted by Sutripta

Zener?

Well, that is what the package said! And the guy I bought it from at a classic car event, was very adamant that it was the latest new technology. And you know me, always a sucker for the latest and greatest technology.

Actually I always thought of it as terminal bridge fuse.

In its most rudimentary shape, something like this:

https://www.autoelectricsupplies.co....48/category/30

Mine certainly looks different though, more like a sort of knife type fuse. (see earlier image)And it has a little red light on it. Only comes on when the knob is loosened, i.e. when the power supply to the car is disconnected. So it is more than just a fuse. There are diodes, including zener diodes that emit light as well of course.

Last night, after I read your post, I decided to take this thing apart. However, it appears to be stuck solid. I do not want to mess with it, until after this weekend Concour d’Elegance! More to come.

Jeroen

[Sutripta]

Originally Posted by Jeroen

Well, that is what the package said!

So what are your (technical) thoughts now on the 'zener' matter?

Regards
Sutripta