18 Volt Cranking Circuit Diagram Here

18 Volt Cranking Circuit Diagram Here

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Discussion

Penelope Stopit

Original Poster:

11,209 posts

108 months

Sunday 16th July 2017
quotequote all
I have now finished this circuit that will give 18 Volts to the starter motor when cranking from the ignition switch, included in this circuit are 4 relays that will ensure that none of the batteries can short circuit and cause a fire should any one of the 4 solenoids contacts weld closed , many thanks to Max_Torque for pointing out the safety issues with my original diagram, I have also added a 5th relay to protect the starter motor should there be a failure and a permanent 18 Volts is supplied to the starter and crank terminal. The solenoids used all have a third contact that is normally used for a 12 Volt supply to a ballast resistor circuit, I have utilised this third contact to operate the safety relays
I will leave my original post and diagram here below. Thank you to those that gave good input



Please, I need your opinions on this diagram. Although I have titled this topic "18 Volt Cranking" it gets better than this, I have calculated a voltage of approximately 14.8 / 15 volts at the starter motor during cranking and believe this will have no drastic effect on the starter motor or its solenoid if put into long term use
Obviouly all the cables from the batteries to the solenoids contacts are of the heavy duty battery cable type
The diagram is drawn to show the circuit with ignition on, when cranking the relay will switch in and the two continuous current solenoids will drop out followed by the two standard starter solenoids pulling in. Battery 3 is in parallel with battery 2 and they are in series with battery 1 when the engine is running and they all charge from the vehicle alternator. During cranking battery 3 is in series with batteries 1 and 2 and 18 volts is supplied to the starter motor, this voltage obviously drops once the starter motor kicks in
Battery 4 if fitted would aid in balancing the batteries out (2 x banks of 2 parallel connected 6 Volt batteries connected in series with eachother will improve the charging conditions and give a better battery life)
I am aware of the fact that there would be a problem if at least one particular solenoid did not drop out before the other pair pulled in and I will be adding a fix for this tomorrow
Thank you in advance


Edited by Penelope Stopit on Tuesday 18th July 18:23

eliot

11,364 posts

253 months

Sunday 16th July 2017
quotequote all
what's wrong with the normal 12v system that's been fitted to thousands of rv8's for decades?

All those connections are just adding complexity, points of failure and potential for more voltage drop across all those heavy duty solenoids, cables and connectors.

In my experience the standard system on any car car be improved with good quality THICK cables with proper crimped eylets and similar for the earth strap.
I use the 415A 60mm2 stuff listed here:
http://www.vehicle-wiring-products.eu/product.php/...
It's thick, but you dont get any volt drop!

Do the TVR engines use the gear reduction starter motors found on th P38 RR - they spin the engine effortlessly and start it in no time.

Edited by eliot on Sunday 16th July 21:49

200Plus Club

10,676 posts

277 months

Sunday 16th July 2017
quotequote all
I once used 18v to crank a brand new and tight LS6. After ten mins running in a normal red top competition battery started her with ease. There is no reason why you'd ever need 18v regularly. A high torque starter and quality heavy duty high cranking load capable battery will start most things petrol related.

Multiple batteries in a car like that is asking for a short circuit (once will do it) and a small fire or explosion imho

phillpot

17,105 posts

182 months

Sunday 16th July 2017
quotequote all


Just checking the date................... no, it's not April.

TwinKam

2,937 posts

94 months

Sunday 16th July 2017
quotequote all
24v starting was common on rally cars (eg Escort BDAs) in the 70s and 80s but I don't think it's done nowadays; possibly because starter motors and batteries are so much better now.
And I can tell you it was a LOT simpler than that set-up!

RayTVR

1,040 posts

142 months

Sunday 16th July 2017
quotequote all
rofl
phillpot said:
Just checking the date................... no, it's not April.
rofl

TobyLerone

1,128 posts

143 months

Sunday 16th July 2017
quotequote all
Penelope Stopit said:
Technical babble and overly complex Heath Robinson contraption hair-brained scheme. See below for added confusion

Errrrr..... u wot m8?

So... What exactly are you trying to start?

If it's something big like an agricultural engine or generator - why not just use a regular 24v system. Easy to bastardise a simple system using a 24v hgv starter, solenoids and switches. And you only need two batteries, in series, which don't need any balancing.

If it's something with a native 12v system, why not get a high torque starter, and have two batteries in parallel. My Landcruiser does - is 12v, with two batteries to aid cold starting (think severe artic). With two large 12v batteries providing a high rating for your CCA, you won't need some crazy st like 3 batteries and a fourth in series-parallel with diodes and rectifiers and lord only knows what else you wanted to throw in.

Plus, it's friggin lighter! Batteries are dense, and weigh a lot in relation to their size. High current cable is no joke either. And then you have the cost... This stuff, for high quality gear, really ain't cheap.

If the standard set up is way inferior, and even a complete refurbishment (ALL new switches, relays, solenoids, starter, cable and battery), then I suggest you look at something like my two suggestions.

Do it your way if you're feeling rich as dick / mental / you're the previous owner of my car, but there is definitely a better way.

Penelope Stopit

Original Poster:

11,209 posts

108 months

Monday 17th July 2017
quotequote all
[quote=Penelope Stopit]Please, I need your opinions on this diagram. Although I have titled this topic "18 Volt Cranking" it gets better than this, I have calculated a voltage of approximately 14.8 / 15 volts at the starter motor during cranking and believe this will have no drastic effect on the starter motor or its solenoid if put into long term use
Obviouly all the cables from the batteries to the solenoids contacts are of the heavy duty battery cable type
The diagram is drawn to show the circuit with ignition on, when cranking the relay will switch in and the two continuous current solenoids will drop out followed by the two standard starter solenoids pulling in. Battery 3 is in parallel with battery 2 and they are in series with battery 1 when the engine is running and they all charge from the vehicle alternator. During cranking battery 3 is in series with batteries 1 and 2 and 18 volts is supplied to the starter motor, this voltage obviously drops once the starter motor kicks in
Battery 4 if fitted would aid in balancing the batteries out (2 x banks of 2 parallel connected 6 Volt batteries connected in series with eachother will improve the charging conditions and give a better battery life)
I am aware of the fact that there would be a problem if at least one particular solenoid did not drop out before the other pair pulled in and I will be adding a fix for this tomorrow
Thank you in advance




There seems to be some misunderstanding here
I am asking for opinions about my diagram as in, do any of the technical people that visit this forum see anything that I have overlooked
As previously mentioned, I have spotted a possible problem that may arise if there was a conflict in the timing of certain solenoids dropping out when others are pulling in and will later post the fix for this
Should any member with much automotive electrical technical knowledge visit this topic, will you kindly look over my diagram and point out anything that I may have overlooked.
Thank you in advance
I haven't put my time into this so as to suffer the ignorance of some members that have posted here

phillpot

17,105 posts

182 months

Monday 17th July 2017
quotequote all
As this is far from TVR specific maybe you'd be better off clogging up asking on a more general forum?

200Plus Club

10,676 posts

277 months

Monday 17th July 2017
quotequote all
Penelope Stopit]enelope Stopit said:
Please, I need your opinions on this diagram. Although I have titled this topic "18 Volt Cranking" it gets better than this, I have calculated a voltage of approximately 14.8 / 15 volts at the starter motor during cranking and believe this will have no drastic effect on the starter motor or its solenoid if put into long term use
Obviouly all the cables from the batteries to the solenoids contacts are of the heavy duty battery cable type
The diagram is drawn to show the circuit with ignition on, when cranking the relay will switch in and the two continuous current solenoids will drop out followed by the two standard starter solenoids pulling in. Battery 3 is in parallel with battery 2 and they are in series with battery 1 when the engine is running and they all charge from the vehicle alternator. During cranking battery 3 is in series with batteries 1 and 2 and 18 volts is supplied to the starter motor, this voltage obviously drops once the starter motor kicks in
Battery 4 if fitted would aid in balancing the batteries out (2 x banks of 2 parallel connected 6 Volt batteries connected in series with eachother will improve the charging conditions and give a better battery life)
I am aware of the fact that there would be a problem if at least one particular solenoid did not drop out before the other pair pulled in and I will be adding a fix for this tomorrow
Thank you in advance




There seems to be some misunderstanding here
I am asking for opinions about my diagram as in, do any of the technical people that visit this forum see anything that I have overlooked
As previously mentioned, I have spotted a possible problem that may arise if there was a conflict in the timing of certain solenoids dropping out when others are pulling in and will later post the fix for this
Should any member with much automotive electrical technical knowledge visit this topic, will you kindly look over my diagram and point out anything that I may have overlooked.
Thank you in advance
I haven't put my time into this so as to suffer the ignorance of some members that have posted here
my qualifications are in Electrical and electronic engineering, but to be honest, i cant be arsed.

Penelope Stopit

Original Poster:

11,209 posts

108 months

Monday 17th July 2017
quotequote all
200Plus Club said:
my qualifications are in Electrical and electronic engineering, but to be honest, i cant be arsed.
Thank you for your efforts

200Plus Club

10,676 posts

277 months

Monday 17th July 2017
quotequote all
you had my advice earlier. stop wasting your time.

Penelope Stopit

Original Poster:

11,209 posts

108 months

Monday 17th July 2017
quotequote all
phillpot said:
As this is far from TVR specific maybe you'd be better off clogging up asking on a more general forum?
The chances are that I am well off the mark here, I get an inkling that you don't like me

Penelope Stopit

Original Poster:

11,209 posts

108 months

Monday 17th July 2017
quotequote all
200Plus Club said:
you had my advice earlier. stop wasting your time.
Wrong, I suffered your ignorance earlier

200Plus Club

10,676 posts

277 months

Monday 17th July 2017
quotequote all
Penelope Stopit said:
200Plus Club said:
you had my advice earlier. stop wasting your time.
Wrong, I suffered your ignorance earlier
you're funny :-) let me know how you get on with your "project" lol.
ttfn

phillpot

17,105 posts

182 months

Monday 17th July 2017
quotequote all
Penelope Stopit said:
The chances are that I am well off the mark here, I get an inkling that you don't like me
It's not that I dislike you Penny, I don't even know you. It's more a matter of respect. Rather than all your theoretical "brain waves", if you could come on here with just one tried and tested solution for a known issue that you had come up with and fitted to your car then myself (and possible one or two others) may take interest.

The problem was.......

I did this........

No issues since smile

Steve_D

13,737 posts

257 months

Monday 17th July 2017
quotequote all
I can't claim to know much about electrics but you may get a better response from those that do if you were to describe what you plan to use this circuit for and why you think it is required.

As a general observation from a TVR standpoint I can't see why it would be required, it would add considerable weight and cost a pretty penny.

Steve

200Plus Club

10,676 posts

277 months

Monday 17th July 2017
quotequote all
there is a parallel thread about this elsewhere, where his charm and skill shines through even better. i wouldn't persevere on this one offering commonsense help.

TwinKam

2,937 posts

94 months

Monday 17th July 2017
quotequote all
I think it needs more solenoids, lots more solenoids. And a flux capacitor. Probably.
silly
Have you considered the shotgun cartridge method of starting. If it was good enough for Supermarine, Massey Furguson...

magpies

5,129 posts

181 months

Monday 17th July 2017
quotequote all
something like this used on rally cars