| Author | Message | ||
     Brian Vogel Grand Master Username: guyslp Post Number: 1572 Registered: 6-2009 |
What follows is probably going to come across as somewhat snarky, but that's really not the intent and my question is sincere. Over the years I keep hearing, again and again, about the need for the ability to disconnect the battery in a Shadow if it's going to sit for any period of time over a week or so. I've found this to be a necessity, and have done so myself. What I also keep hearing is about the need for a battery cut-off switch, which I've always found to be overkill since both of my cars have this arrangement for the negative battery cable just outside the battery box: SRH33576, with carpet removed  LRK37110, with carpet in place  It takes a few seconds, literally to undo the wing nut to isolate the battery when necessary. A cut-off switch seems utterly superfluous. However, this makes me wonder, was this arrangement something that was introduced "mid way through somewhere" in the Shadow's production run? Do earlier cars have some alternate arrangement that makes disconnecting the negative battery cable impractical/difficult or impossible? Brian | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 347 Registered: 5-2015 |
I don't think RR intended that the switch was to be used for such a short period. The intention was maybe 1 month or more of storage. To remove my battery terminal I have to remove the carpet cover then the the battery cover then a spanner to remove the terminal. Or just the carpet cover and the wing nut. But being RR they put an isolator switch in a convenient place. I think it's a good idea to have a switch so much easier. In my experience any make car that is unused for say 2 weeks is liable to maybe not start due to battery sag. Especially if the car when it is used doesn't go far. These switches are available from AES. Also different looking ones that do the same job. I like my one. The knob is black and round with instructional arrows in white. So Rolls-Royce. Also next door to the switch is the power socket. Anything less then it's not good enough for the best car in the world. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1573 Registered: 6-2009 |
Bob, What I'm getting at is that: 1) The SY2 cars (or at least any of the ones I've seen) don't have any sort of battery cut-off switch as standard equipment. 2) There's easy access to the wing nut for the negative battery terminal. Hence a cut off switch is entirely superfluous. If I hear one more of the "not good enough for the best car in the world"-type comments from any quarter, having now owned two and knowing that they have as many flaws as any other car does, I believe I shall wretch. That doesn't mean I haven't very much enjoyed my period of custodianship and what it continues to teach me. Rolls-Royce motorcars should not be false idols for fawning worship. Based upon your observations about your car it would appear that earlier Shadows did have a battery cut-off switch as standard equipment. Brian | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 887 Registered: 5-2012 |
Hi Brian My car (74 SY1 - SRX18501) is exactly the same as yours. A wing nut in the same position just under the removable carpet that covers the battery. There is no evidence whatsoever that an isolator switch was ever fitted by Crewe when the car was manufactured. I have however fitted an isolator switch myself. I know this is all marginal and I could just undo the wing nut, but I much prefer the ease of using the switch. It really comes into it's own when I am working on the car. In my recent attempt to fix the wipers it was so convenient to flip it off and on, repeatedly, between tests. The other thing I like about it is I can keep the trunk carpet undisturbed. Before I fitted the switch I had a tendency to leave the battery cover lying around in the trunk. It just appeals to me that the car is more complete with the switch. Like many things, ultimately, it is just down to personal preference. Geoff | ||
| David Gore Moderator Username: david_gore Post Number: 1705 Registered: 4-2003 |
I see an immediately accessible battery isolating switch as being a worthwhile safety enhancement; there is a reason why racing cars are required to have a sticker showing the battery location in the vehicle and an isolating switch is invariably fitted for use in emergencies/accidents for the safety of the driver[s] and incident response personnel. Personally, I believe an accessible isolating switch is a useful addition to the vehicle for use in emergency situations or in routine maintenance when it is necessary to disable the electrical system. DRH14434 [manufactured early 1973] had the wing nut connection and was prone to the battery going flat due to drain from the electric clock if the car was not driven at least once a fortnight. I purchased a marine battery isolating switch not long before I ceased looking after the car following complaints from the other driver about the nuisance of having to reconnect the battery before she could use the car but this was never installed. Geoff's comments are well worth considering if you are a DIY custodian of any motor vehicle not just R-R/B vehicles. | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 350 Registered: 5-2015 |
Brian, I didn't mean the best car in the world as a sarky comment. Some of the features of these cars came from owners. The factory would then think that the idea was a good on so it gets on the options list. This is because the factory is always trying to make the best car in the world. They get dam close. When I look at stuff on my car I see not only quality but also a style theme. The rad cap the oil filler cap the fuel cap the parking light switch and the battery switch. They all look quality. The rest of the switch gear all matches and the quality of the chrome etc is second to none. The Shadow has a very well made electrical system. The fuse board is first class. In contrast my Jeep has rubbish switch gear and the feel when used is zero. The fuse board is awkward to access. The isolator switch is used by many high end car makers. It's what customers expect. So thats what customers get. | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 888 Registered: 5-2012 |
Hi Brian I've just checked out this thread. http://au.rrforums.net/forum/messages/17002/17038.html From the discussion later in the thread it appears to be fairly conclusive the Silver Shadow was never fitted with an isolator switch as standard. Geoff | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1574 Registered: 6-2009 |
Well, at least I have the answers to the questions I posed, and for that I'm grateful. I have nothing, at all, against installing a battery isolation switch if this is something you would like to have for whatever reason. For myself, the RRs have the easiest battery disconnect feature I've ever encountered on any car I've owned. Most have none other than popping one of the connection off of the battery terminal. For myself, what's already a feature of the car is more than sufficient to meet my wants and needs. Brian | ||
| Chris Miller Grand Master Username: cjm51213 Post Number: 378 Registered: 5-2013 |
Hi Brian, The '66 cadaver car has a switch, and for good reason. The battery has a plastic cover which is also subsequently covered with carpet. Access to the battery is inconvenient at a minimum. The '72 does not have a switch, and I don't see why access to the battery is any less inconvenient. I think this was part of the "cost improvements" that expressed themselves in many ways, including a reduction of the elegance of the interior, somewhere around '69, just before bankruptcy, however it could also be that electrical improvements deemed the cut-off unnecessary. Chris. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1575 Registered: 6-2009 |
Chris, Based on all that's come before, including in the thread Geoff posted the link to, none of the SY cars came equipped with a cutoff switch from Crewe unless it was special order. I know that the later SZ cars, or at least quite a few of them, did. It appears that quite a few owners have retrofitted these on the Shadow series cars. For myself, I just don't find zipping a piece of velcro away and then undoing a conveniently exposed wing nut particularly inconvenient. I don't know if the earlier cars fastened the cardboard/carpet battery box cover with something other than Velcro. If they did I'd presume it would be the same Tenax fasteners that are used on the carpets in the boot/trunk and the passenger compartment. If I'm working on the car I just leave the carpet battery cover undone until I have completed the work. Brian | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 949 Registered: 9-2004 |
Why not check for the electrical drain fault in the first place [diodes are cheap as chips to replace] and none of this isolator switch or battery terminal nonsense will be needed. The clock will not run the battery down for months. The SY cars have all the electrical saftey features in place regards to accidents however fuel and brake fluid fires when happens it is time saved to use a fire extinguisher first not fiddle with a wingnut. I have found in most cases when OEM fitted to cars that have no battery drain probs the cars have other electrical failings after time due to fiberglass bodys etc. | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 354 Registered: 5-2015 |
Glass fibre bodied cars electrical systems are easy to sort out by running separate fat earth leads to components such as rear lights. I don't know why this is not done when the car is built. | ||
| David Gore Moderator Username: david_gore Post Number: 1709 Registered: 4-2003 |
Hi Pat, I did a lot of checks on the vehicle to find the source of the battery drain including all the diodes I could find. Later on, I was told diodes could also be found hidden in the wiring harness.... I did disconnect the clock [the alternative one to the Smith's clock - I have forgotten the name but it started with K] to confirm it was the problem. The current draw was in milliamps and it was my theory that the current was enough to sulphate the battery plates over time which stopped the battery supplying sufficient power to the starter motor. A short hit with a battery charger which removed the coating would restore full battery power to enable the car to be started. I did fit a new battery to see if this would help without success. | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 356 Registered: 5-2015 |
Kenzil. I suspect that real problem is that the battery is too small. All batteries discharge over time. The battery specified seems to only need a small amount of discharge and the car won't start. The starter motor is about 2.5 hp. Thats 155 amps required. It doesnt take long to further discharge the battery because its not fully charged in the first place. Result no start. I get round this by charging every month and using the isolator switch. My Jeep is not as bad but given half a chance the battery will sag if the engine doesn't catch first time after a 2 week lay up. The parasitic load on the jeep is 30 milli amps. Radio and ECU memory. The clock has a AA battery inside. The Shadow is about the same 30 milliamps. The diodes in the alternator can fail and cause AC in the electrical system. The battery can be damaged by stray AC. I have a battery charging station in my garage. The charger is a Crypton 7.5 amp jobbie on a timer plug thingy. Also I have a small portable Halfords charger and a Sealy 160 amp charger should I be in a hurry. The Sealy can be set at 3 amps only and it will start an engine without charging the battery( charger on max power) I don't often use this bit. The sealy will after 15 min charge the battery enough to start the engine. It is possible to fit a bigger battery by removing the existing plastic battery cartier and cutting the sheet metal. Or two 6volt batteries. The newer luxury cars have batteries twice the size. | ||
| David Gore Moderator Username: david_gore Post Number: 1710 Registered: 4-2003 |
Hi Bob, Thanks - I had a "senior's moment" and for the life of me couldn't remember the brand name. Your comments re the battery size and starter motor power are interesting - could well explain why starting is problematic after a relatively short period of inactivity. | ||
| Bob Reynolds Grand Master Username: bobreynolds Post Number: 309 Registered: 8-2012 |
The standard battery is plenty big enough. My car stands idle for weeks. After 4 weeks it will still spin the starter at a good speed and the engine fires in under 2 seconds. I've got the standard clock connected, the drain is negligible really, compared to the capacity of the battery. I did fit a new battery last year, and that is probably the main reason. Do not let lead-acid batteries sit discharged, even partially discharged, for any length of time. It will ruin them. And never fast-charge a battery, unless you're desperate. Trickle charge only. Whenever my car is not being used I will do the starting test about every 4 weeks and then put the battery on a trickle charge to keep it topped up. To be honest, I think it would go for 6 weeks and still start OK, but I've never left it that long. I do not disconnect the battery. A small trickle discharge followed by an occasional trickle charge keeps the battery cycling, which possibly keeps it in better condition than leaving it disconnected and not doing anything. Even if it is disconnected, you absolutely must keep it charged up, as it will gradually self-discharge anyway. Don't leave it on permanent charge though. Switch off when the charger says it's full. Looking after your battery is mostly common sense. | ||
| Mark Aldridge Prolific User Username: mark_aldridge Post Number: 236 Registered: 10-2008 |
My Shadow has a battery cut off switch with a 3 amp quick blow fuse bypassing it to keep clock and radio settings.. The switch is purely for protection, having had 2 friends have their classic cars damaged by electrical fires when parked. ( cutout failure and underdash wiring fault) I also have a battery trickle charge ( max 1/2 amp output ) permanently connected when the car is not in use, timeswitched for 8 hours daily, for each of my cars. The battery in my S1 ( standard 069 rolls fitted battery) lasted 9 years and was a cheap 2 yr guarantee battery ! | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1578 Registered: 6-2009 |
Just curious as to what constitutes "fast charging." I have an older Schumacher charger that has a 2 Amp and 10 Amp charge setting as well as a 50 Amp "starting" setting. I always considered the 2 Amp to be trickle and the 10 Amp to be slow (because it still takes a number of hours to charge up the battery). Brian | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 357 Registered: 5-2015 |
10 % of amp hour rating is what is recommended by battery guys. 100 amp hour charge at 10amps. Fast charging is to be avoided. Because a battery will only accept so much before it heats up and starts gassing. Fast charging tends to sit on the plate surface. If the fast charge is stopped the electric elves will find their way to deeper parts. This will then drop the the voltage on the surface of the plate. Over charging can blast the sulphate off plates. Batteries that don't physically move can get stratified with acid at the bottom and weak acid at the top. Battery banks for telephone systems bubble air into the electrolyte to stop this. Charging also mixes the electrolyte. Shaking the battery does the same thing. Shaken not stirred 007. The line where fast charging starts at a guess is 20% of amp hour. Today I have been sorting out my boot lid carpet. So out of interest I done a parasitic load test. And got 20 milli amps. Also my carpet covers half the wing nut earth post. So undoing is very awkward. I note that Bob Reynolds has no trouble. So maybe our 40 year old starters need a service. To test a starter clamp in vice and stuff a bit of soft wood into the gear. If it chews the wood up then its good to go. Or find a shop with a starter load tester, rare now. 1/2 amp charging is maintenance charging and very useful at stopping sulphation. Fixed voltage charging. This what a normal sub £50 charger does. The battery voltage is say 12v. Which is quite low. The charger needs extra volts to overcome internal resistance. 2 volts approximately. So if a fully charged battery has 12.6v 2.1v per cell. To get there a charger will need 14.6v. As the battery volts go up the difference between the battery volts and charge volts gets narrower which makes the amps drop off. A further complication is that as the load comes off the charger the charger volt will increase a bit. These sort of chargers are absolutely fine for charging batteries. The more complex ones such as pulse charging variable volt jobbies are not any better. Also its not necessary to buy a charger based on engine size. A small diy charger will charge big truck batteries it just takes longer--- days. Small batteries such as motor bike need care. One way is to connect in series a light bulb of say 21w. This will limit amps. So that I can keep an eye on battery charging I connect a voltmeter in circuit. | ||
| David Gore Moderator Username: david_gore Post Number: 1711 Registered: 4-2003 |
The characteristic formation of hydrogen gas during battery charging is directly related to the voltage applied to the battery when charging. Outgassing occurs once the charging voltage is greater than 14V and this is why float chargers operate below 13.8V to prevent electrolyte loss over time due to electrolysis. Where the plates are sulphated, the charging voltage needs to be greater than 14.4V to remove the sulphate however this results in Hydrogen generation, heating of the battery, loss of electrolyte and possible over-charging. Floating chargers only work effectively on fully-charged batteries and should not be used on partly/fully discharged batteries as they will not remove the Lead sulphate insulating the plates in the battery. More information on the link below: http://batteryuniversity.com/learn/article/charging_the_lead_acid_battery P.S. Bob, your milliamp reading is similar to what I recorded for DRH14434, the starting problem disappeared when I disconnected the clock and returned when the clock was reconnected. I also had the clock overhauled by an instrument fitter with experience with Kenzil clocks who advised there was nothing wrong with the clock. | ||
| Bob Reynolds Grand Master Username: bobreynolds Post Number: 310 Registered: 8-2012 |
"Just curious as to what constitutes "fast charging." I have an older Schumacher charger that has a 2 Amp and 10 Amp charge setting as well as a 50 Amp "starting" setting. I always considered the 2 Amp to be trickle and the 10 Amp to be slow (because it still takes a number of hours to charge up the battery)" I would consider 10 amps to be fast. I just have a small cheap constant voltage charger. When first connected it will show about 4 amps, but this quickly drops to around 2 amps after a few minutes. After an hour or so it will drop to about 1 amp. I might leave it switched on for a couple of days, by which time the current has dropped to about 1/2 an amp. | ||
| Robert Noel Reddington Grand Master Username: bob_uk Post Number: 361 Registered: 5-2015 |
Bob Reynolds your cheap charger operates as a typical fixed voltage charger. These are chargers are fine and 4 amps is nice and safe and gentle. 10 amps on a 75 amp battery is a bit fsat almost. The correct charge is 7.5 amps but as discussed the amps drop off as the battery volts pick up. Dave Gore. I read battery uni web site 2 years back. This site us a must for understanding lead acid batteries. Theres to lot more to them than first meets the eye. The knowledge gives one the ability to prolong battery life maybe double. 20 milliamps over a month is like side lights left on 1 day add in a 40 year old starter motor and a no start is likely. The amount of enough needed to just turn a nice looking knob and be rewarded with a defined click as the boot light gors out is nil. Its a pleasure. I have seen car clocks that have internal AA battery and don't use any main battery power unless the lights are on. Separate circuit. In daily driver mode the battery holds up well. But theres no margin for safety. I would like a bigger battery because it's in the back of my mind that one must be careful when the engine is stopped with electrical stuff. Modern radios use very few amps. Interior lighting can pull the battery down. LED bulbs cpuld work well. Get soft light ones not blue tinge ones. As soon as my shows signs of distress it gets replaced. 4 years on present battery now £45. A tip is to measure battery voltage in the shop and check manufacturing date. Don't buy 12 month old new batteries or ones that show less than 12.55 volts. Batteries stored in shops are wearing out sitting on the shelf. Often they aren't charged properly if at all. Storing batteries with no electrolyte need to filled and charged which takes for charging at least 10 hours. Often the guy just fills yhe battery and hands it over or fast charges it relying upon the vehicles alternator to take up the slack. This doesn't work because who drives 10 hours to charge a battery. I am a bit fussy over batteries because no start means boat anchor. Also I have a 1 kilo watt generator which has a battery charge bit. I tried it and it worked fine. It took 30 mins to charge enough to spin the engine. Which would get One going should one be stranded plus multiple goes no problem till the petrol runs out. Bit inconvenient carrying a generator in the boot. |
