Keeping the battery maintained

HarryM1BYT · 25th July 2020, 21:34

My regime for several years now, to keep my 75's battery maintained whilst parked unused in my garage, has been one of plugging my Lidl smart charger in via a ciggy lighter socket - Mk II so they remain powered/ connected with ignition off and doing this once per month for a couple of days.

New battery installed, so I decided to look at my regime and see if there might be a better method of doing it automatically....

A smart charger would not work, because a button needed to be pressed to start the charge, so I dug out one of my more basic voltage controlled ones, and powered it via a time clock - on once per day, for just 15minutes. It senses whether a battery is correctly connected, before it will attempt to charge, but it discharges the battery at 5mA when not powered add my car's own discharge of 20mA whilst parked, so 25mA. So far, so good.

13amp socket, plug in time-clock, charger and two terminal posts for crocodile clips are all mounted on a roof beam, with a long lead down from the two posts terminating in a ciggy lighter plug.

On testing it, I then found there was quite a lot of volts drop, particularly in the car's loom, between the ciggy lighter socket and the battery - almost 1.5v making charging far too slow. So I spent a bit of time thinking about how to resolve that, without having to lift the bonnet to clip charger leads onto the battery....

I was thinking I might have to add a special charge socket, wired directly to the engine fuse panel, but this morning came up with an easier way. Long ago, wiring the car for towing, I added the heavy feed (heavy, less resistance and volts drop) from the engine fuse panel, to just behind the glove box - that is live all of the time, but unused when not actually towing, so I used that as a +ve source and connected the -ve to a chassis earth terminal down the side of the inner wing, by the passenger's feet.

I looked for somewhere hidden, to mount a new, single ciggy lighter socket and decided I could just fit one in behind the glove box lid, side of the surround, nearest the driver. It is quite narrow, but was just wide enough for a socket. Close the glove box lid and the socket is hidden from view.

Result- volts drop in minimised and the battery is brought rapidly up to fully charged voltage. I just drive in, open the drivers door, grab the lead and plug it in and forget about it. As ciggy sockets are dodgy, I also put together a flashing LED circuit across the terminal post on the roof beam. That draws around 0.010mA, but I can confirm with it that my connection to the car is OK as I get out.

I have quite a number of lead-acid and gell cells around the place, so also thought it was about time I bought myself a battery analyser, so I ordered up an Ancel BA201. I paid £24 for it, delivered from Ancel's Polish depot. You simply clip it on the battery, tell it the type, capacity of the battery, push a button and it can check the state of charge, state of health, the cranking and the alternator. I'm quite impressed with it, colour display, shows the graphs, but impossible to read in daylight. My ten year old battery, which I kept as an emergency spare, showed as still having some life in it, at 45%.

The analyser can tell the difference between your connecting directly to the battery, or to the main feed of the fuse box -it shows 100% across the new battery I fitted last week, but only 1% if connected to the end of the heavy cable at the fuse box. It obviously applies some small amount of load and measures the volts drop, from which it can calculate the tiny amount of resistance. The higher the resistance, the worse the condition of the battery.

COLVERT · 25th July 2020, 21:50

You lose 99% through the main cable ?????----

From 100% down to 1%.----Yikes !!!

clf · 25th July 2020, 22:25

Quote:

Originally Posted by HarryM1BYT

My regime for several years now, to keep my 75's battery maintained whilst parked unused in my garage, has been one of plugging my Lidl smart charger in via a ciggy lighter socket - Mk II so they remain powered/ connected with ignition off and doing this once per month for a couple of days.

New battery installed, so I decided to look at my regime and see if there might be a better method of doing it automatically....

A smart charger would not work, because a button needed to be pressed to start the charge, so I dug out one of my more basic voltage controlled ones, and powered it via a time clock - on once per day, for just 15minutes. It senses whether a battery is correctly connected, before it will attempt to charge, but it discharges the battery at 5mA when not powered add my car's own discharge of 20mA whilst parked, so 25mA. So far, so good.

13amp socket, plug in time-clock, charger and two terminal posts for crocodile clips are all mounted on a roof beam, with a long lead down from the two posts terminating in a ciggy lighter plug.

On testing it, I then found there was quite a lot of volts drop, particularly in the car's loom, between the ciggy lighter socket and the battery - almost 1.5v making charging far too slow. So I spent a bit of time thinking about how to resolve that, without having to lift the bonnet to clip charger leads onto the battery....

I was thinking I might have to add a special charge socket, wired directly to the engine fuse panel, but this morning came up with an easier way. Long ago, wiring the car for towing, I added the heavy feed (heavy, less resistance and volts drop) from the engine fuse panel, to just behind the glove box - that is live all of the time, but unused when not actually towing, so I used that as a +ve source and connected the -ve to a chassis earth terminal down the side of the inner wing, by the passenger's feet.

I looked for somewhere hidden, to mount a new, single ciggy lighter socket and decided I could just fit one in behind the glove box lid, side of the surround, nearest the driver. It is quite narrow, but was just wide enough for a socket. Close the glove box lid and the socket is hidden from view.

Result- volts drop in minimised and the battery is brought rapidly up to fully charged voltage. I just drive in, open the drivers door, grab the lead and plug it in and forget about it. As ciggy sockets are dodgy, I also put together a flashing LED circuit across the terminal post on the roof beam. That draws around 0.010mA, but I can confirm with it that my connection to the car is OK as I get out.

I have quite a number of lead-acid and gell cells around the place, so also thought it was about time I bought myself a battery analyser, so I ordered up an Ancel BA201. I paid £24 for it, delivered from Ancel's Polish depot. You simply clip it on the battery, tell it the type, capacity of the battery, push a button and it can check the state of charge, state of health, the cranking and the alternator. I'm quite impressed with it, colour display, shows the graphs, but impossible to read in daylight. My ten year old battery, which I kept as an emergency spare, showed as still having some life in it, at 45%.

The analyser can tell the difference between your connecting directly to the battery, or to the main feed of the fuse box -it shows 100% across the new battery I fitted last week, but only 1% if connected to the end of the heavy cable at the fuse box. It obviously applies some small amount of load and measures the volts drop, from which it can calculate the tiny amount of resistance. The higher the resistance, the worse the condition of the battery.

I am not sure I totally understand the wiring route, however (I am probably wrong on this), but if you have a permanent live from the battery for towing, could you have rigged up a towing plug, with just a live and earth pins populated, then to the charger/maintainer. Then to use it, just plug into the towing socket when you park up? (I know it is all buttoned up now, but am just curious if I understand the issue and if that could work)

HarryM1BYT · 26th July 2020, 06:01

Quote:

Originally Posted by clf

I am not sure I totally understand the wiring route, however (I am probably wrong on this), but if you have a permanent live from the battery for towing, could you have rigged up a towing plug, with just a live and earth pins populated, then to the charger/maintainer. Then to use it, just plug into the towing socket when you park up? (I know it is all buttoned up now, but am just curious if I understand the issue and if that could work)

No, that wire at the towing socket is only live when the engine is running and the alternator charging. It powers the fridge and charges the caravan's battery. There is a voltage operated relay in the boot.

Besides, its much easier/quicker to plug into the cabin and the charge cable drapes over the steering wheel, so no chance of driving off with it still plugged in.

The route is - 240v mains socket > plug in timer > charger > clipped to a pair of terminal posts - those are all over head, fixed to a roof beam.

From the terminal posts > a long lead with a ciggy plug on the end, hanging adjacent to the drivers door.

The terminal posts are just a couple of brass bolts knocked into holes in the roof timbers - So I didn't need to remove the croc clips from the charger, to which I added a flashing LED circuit. As said, I just drive in the garage, grab the lead and plug it into the new socket, check my LED circuit is flashing and can then just forget about it.

It was working before, despite the volts drop. I just wanted something a bit more automated (no having to remember to put the battery on charge if I haven't needed to use the car).

BRG75 · 26th July 2020, 06:04

Long before chargers became so sophisticated, and battery voltage apparently critical, I did precisely as clf described. A charger with just it's two wires going to a trailer / caravan plug.

It worked admirably.

HarryM1BYT · 26th July 2020, 06:22

Quote:

Originally Posted by COLVERT

You lose 99% through the main cable ?????----

From 100% down to 1%.----Yikes !!!

That's what the analyser said

I ran the test three times, just to be sure, adjusting the clips between the tests.

I never had much faith in the ability of the modern electronic analysers, preferring the simple high current testers with a meter in parallel, but I'm quite impressed with this gadget and its low current test method. It does the test in around 1 second, using some quite thick test leads, but the unit barely gets warm.

I was also surprised by how low the battery voltage dipped on cranking graph - it recorded a low of 8.75v, despite my diesel starting instantly and it being a new battery.

raykay · 26th July 2020, 11:39

Quote:

Originally Posted by HarryM1BYT

No, that wire at the towing socket is only live when the engine is running and the alternator charging.

A modern 12S or 13 pin socket should have both a battery live and an alternator feed.

COLVERT · 26th July 2020, 15:09

Quote:

Originally Posted by raykay

A modern 12S or 13 pin socket should have both a battery live and an alternator feed.

As you say.---I've helped several folk to get into their car when locked out due to a flat battery.

Power in to the live socket pin and an earth to the car bodywork. Press your button and you're in .--

HarryM1BYT · 27th July 2020, 07:27

Quote:

Originally Posted by raykay

A modern 12S or 13 pin socket should have both a battery live and an alternator feed.

Having thought about it, you are of course correct.

Borg Warner · 27th July 2020, 16:51

I have a set of leads that came with the the smart charger that attaches permanently to the batteries of all three cars with a female connector, whilst the charger has a corresponding male connector. Have had them connected as required since lock down. Just swap them over as and when and all three car batteries are good with the oldest now some five+ years old.

25th July 2020, 21:34	#1
HarryM1BYT This is my second home 75 Contemporary SE Mk II 2004 Man. Sal. CDTi 135ps, FBH on red diesel, WinCE6 DD Join Date: May 2010 Location: Leeds Posts: 17,273 Thanks: 2,160 Thanked 2,061 Times in 1,586 Posts	Keeping the battery maintained My regime for several years now, to keep my 75's battery maintained whilst parked unused in my garage, has been one of plugging my Lidl smart charger in via a ciggy lighter socket - Mk II so they remain powered/ connected with ignition off and doing this once per month for a couple of days. New battery installed, so I decided to look at my regime and see if there might be a better method of doing it automatically.... A smart charger would not work, because a button needed to be pressed to start the charge, so I dug out one of my more basic voltage controlled ones, and powered it via a time clock - on once per day, for just 15minutes. It senses whether a battery is correctly connected, before it will attempt to charge, but it discharges the battery at 5mA when not powered add my car's own discharge of 20mA whilst parked, so 25mA. So far, so good. 13amp socket, plug in time-clock, charger and two terminal posts for crocodile clips are all mounted on a roof beam, with a long lead down from the two posts terminating in a ciggy lighter plug. On testing it, I then found there was quite a lot of volts drop, particularly in the car's loom, between the ciggy lighter socket and the battery - almost 1.5v making charging far too slow. So I spent a bit of time thinking about how to resolve that, without having to lift the bonnet to clip charger leads onto the battery.... I was thinking I might have to add a special charge socket, wired directly to the engine fuse panel, but this morning came up with an easier way. Long ago, wiring the car for towing, I added the heavy feed (heavy, less resistance and volts drop) from the engine fuse panel, to just behind the glove box - that is live all of the time, but unused when not actually towing, so I used that as a +ve source and connected the -ve to a chassis earth terminal down the side of the inner wing, by the passenger's feet. I looked for somewhere hidden, to mount a new, single ciggy lighter socket and decided I could just fit one in behind the glove box lid, side of the surround, nearest the driver. It is quite narrow, but was just wide enough for a socket. Close the glove box lid and the socket is hidden from view. Result- volts drop in minimised and the battery is brought rapidly up to fully charged voltage. I just drive in, open the drivers door, grab the lead and plug it in and forget about it. As ciggy sockets are dodgy, I also put together a flashing LED circuit across the terminal post on the roof beam. That draws around 0.010mA, but I can confirm with it that my connection to the car is OK as I get out. I have quite a number of lead-acid and gell cells around the place, so also thought it was about time I bought myself a battery analyser, so I ordered up an Ancel BA201. I paid £24 for it, delivered from Ancel's Polish depot. You simply clip it on the battery, tell it the type, capacity of the battery, push a button and it can check the state of charge, state of health, the cranking and the alternator. I'm quite impressed with it, colour display, shows the graphs, but impossible to read in daylight. My ten year old battery, which I kept as an emergency spare, showed as still having some life in it, at 45%. The analyser can tell the difference between your connecting directly to the battery, or to the main feed of the fuse box -it shows 100% across the new battery I fitted last week, but only 1% if connected to the end of the heavy cable at the fuse box. It obviously applies some small amount of load and measures the volts drop, from which it can calculate the tiny amount of resistance. The higher the resistance, the worse the condition of the battery. __________________ Harry How To's and items I offer for free, or just to cover the cost of my expenses... http://www.the75andztclub.co.uk/foru...40#post1764540 Fix a poor handbrake; DIY ABS diagnostic unit; Loan of the spanner needed to change the CDT belts; free OBD diagnostics +MAF; Correct Bosch MAF cheap; DVB-T install in an ex-hi-line system; DD install with a HK amp; FBH servicing. I've taken a vow of poverty. To annoy me, send money. Last edited by HarryM1BYT; 25th July 2020 at 21:44..

26th July 2020, 06:04	#5
BRG75 Gets stuck in Rover 75 Saloon & Tourer, 9th & 10th Rovers Join Date: Nov 2013 Location: Sevenoaks Posts: 973 Thanks: 670 Thanked 290 Times in 195 Posts	Long before chargers became so sophisticated, and battery voltage apparently critical, I did precisely as clf described. A charger with just it's two wires going to a trailer / caravan plug. It worked admirably. __________________ Presently 2004 75 CDTi auto Connoisseur Tourer - White Gold 2001 75 2.5 auto Connoisseur Saloon - White Gold Previously 2002 75 1.8 auto Club SE, 2000 75 1.8 auto Classic SE (Company Car) 1997 420 (Company Car) 1996 216 cabriolet, 198? 213 VDP 1986 SD1 V8 VDP, 1968 2000TC, 1966 2000.

25th July 2020, 21:50	#2
COLVERT This is my second home R75 Saloon. Join Date: Feb 2009 Location: France/or Devon. Posts: 14,003 Thanks: 3,851 Thanked 2,167 Times in 1,816 Posts	You lose 99% through the main cable ?????---- From 100% down to 1%.----Yikes !!!

27th July 2020, 16:51	#10
Borg Warner I really should get out more....... None Join Date: Feb 2010 Location: Suffolk Posts: 2,579 Thanks: 494 Thanked 657 Times in 402 Posts	I have a set of leads that came with the the smart charger that attaches permanently to the batteries of all three cars with a female connector, whilst the charger has a corresponding male connector. Have had them connected as required since lock down. Just swap them over as and when and all three car batteries are good with the oldest now some five+ years old.