Alternator Paralleler Circuit

[Nige123]

like the post below your reply says it DOES SAY you can connect 2 alt's to this I know as my boat has this set up with 2 alt's fitted.......

 

& you could save £200.00 but the cost of replacing my 6 110ah batteries if I got it wrong would put me off a DIY fitting even if the fact that in any event of a fire my insurance would not pay up!

 

I would hate to save £200.00 & end up £40k out of pocket.................

 

 

the unit is quite small & the 2 alt' cables (about 25mm) connect into it & a very large (75mm or so) cable runs a few feet to my bank of 6 110ah batteries & it charges them real quick as it has 2 80amp inputs & a 160amp charging output.....

 

it does what you want it to do & is made for the job comes with warranty & tech' help from experts & if your boat does catch fire & it's due to the product you can take them to court......

 

sorry your trying to re-invent the round thing that cars roll on out of rocks here ;O)

 

I spent the weekend taking my boat from the K&A to Henley on Thames to the 80's festival & my twin alt' charging system works real well!

in fact I now have a Honda E1000 generator for sale as I can see no need for it in the future as the boat system works so well....

 

all lighting & power on the boat comes from the 3kw inverter & I have 12 GU10 spot lights (& 1 bathroom halogen & strip light with shaver point) that I have now fitted LED lamps to, this with the TV running was no problem for the batteries & within a short trip down the river the charging system recharged things to almost full & by the time I got back to my mooring I had full power again......

 

my last boat only had 1 alt' fitted & it would take more then twice the time to recharge half the battery bank I now have so I would say if you are fitting out a boat or you want a better system then look at the link I posted or find something like it to use you won't be disappointed.....

 

as far as I can tell it does what it says on the tin! I run the engine & get hot water & lots of power & as I use my own Bio-Diesel it costs less then it would to run a generator & you don't have to deal with PETROL/LPG on board......

[Sir Nibble]

Mr Broke, (or may I call you Piston) I am sure you are a very knowledgable bloke with a wealth of experience; you are not the only one, do try and remember that. On this board there are people with a lifetimes experience as working technicians and others with barrowloads of qualifications, don't patronise people who for all you know have greater experience or knowledge than you. For instance, Gibbo is regarded as an authority on batteries with years of research data to his name, do not gainsay him unless you have similar resources to back up your argument.

 

Since I had some input to the original discussion I shall post my own conclusions.

 

If you don't mind alternator surgery, bring 3 phase leads out from the unit and connect them to 3 stud mounted diodes on a heatsink and the heatsink to the 2nd battery.

 

If you do mind alternator surgery then source a 3 output blocking diode, connect alternator B+ to the input, the 2 battery banks to 2 outputs and the 3rd output to F+ and warning light isolating from the internal trio.

[pistnbroke]

Bosch RE 55 ( 20 quid )

 

 

However Whatever got me thinking when he said its disconnecting the start battery thats difficult ...so I thought why disconnect it ...the problem is the volt regs are set too high and it gasses ......so if you feed it through a 50 A diode then the voltage is low enough to stop the gassing .

 

The circuit is based on two Bosch RE 55 Regulators which have a link that can be cut to raise the voltage by 1 volt .. these links can be switched so that the voltage will go back to normal at the end of the baulk phase .

 

I am not convinced you need the solenoid ...just leave the two B + connected but if you want a solenoid then the SCR circuit posted previously will work fine . OR build a 10 min unijunction timer to fire the SCR and the solenoid then joins the B+ s

Edited August 30, 2009 by pistnbroke

[WotEver]

Whatever got me thinking when he said its disconnecting the start battery thats difficult ...so I thought why disconnect it ...the problem is the volt regs are set too high and it gasses ......

 

Actually, no.

 

When the two alternators are parallelled the domestic alternator will be giving absolutely the correct voltage for the domestic bank which have been deeply discharged and will require a long charge at an elevated voltage. However, the starter battery has not been deeply discharged (all it's done is start the engine) and so doesn't require the same charge rate. Therefore, once the parallelling has done it's job (get the domestic bank into acceptance faster by providing a higher initial charge current) the parallelling now needs to be disconnected. This allows the starter alternator to supply a nice low float foltage to its battery whilst the larger domestic alternator can continue to fully charge its battery bank.

 

Tony

[pistnbroke]

so actually Yes .....my circuit fills the bill perfect .....float charge for start and fast high volatage charge for domestic reduced at the captains command ........does what it says on the tin ......

 

See you did not last long tony on Boat design .net never seen any one go from reputation of +10 to -14 so fast .....What ever as they say

[tomsk]

Cake anyone?

 

 

http://www.evilmadscientist.com/article.php/circuitsnacks

[pistnbroke]

Tomska ...got it in one

Edited August 31, 2009 by pistnbroke

[Bagpuss]

No. Being Norty means you have to sit on the Norty step in the Virtual Pub.

 

Richard

 

The norty step is atop Sarahb's boat in Barrow upon Soar, I know it coz I Soar it yesterday.

 

On an entirely different note, it seems circuits are being modified without creedence to people suddenly accepting they were wrong which sticks in one's craw slightly...

 

Despite not having done the alt' surgery yet' having paralleled my alts, with some means of switching it off has meant that I've halved my charge time and there's still loadsa water in all my batteries Even the dino's are smiling!

[Sir Nibble]

KISS.

I have had huge fun designing circuits to satisfy unusual requirements, then I realised that the object of the exercise is not to have fun but to engineer the simplest most reliable and effective solution possible. I've certainly done a better job having come to that realisation. That is why I favour the blocking diode solution outlined above since it requires one commercially available component and leaves alternators standard so that off the shelf spares go straight on without modification. The effect is that the engine alternator charges both batteries up to it's regulated voltage and then charges only the engine battery as the (presumably "boosted") domestic alternator takes over. Fully automatic, maintains system separation, simple.

[WotEver]

never seen any one go from reputation of +10 to -14 so fast .....

 

And I should give a sh1t because...?

 

And I'm not off there, if there's a subject that I feel I can contribute to then I will. I won't however stick my oar in when it's not relevant.

 

Speaking of reputations, you should see some of the PMs I received about you... No, maybe you shouldn't.

 

T

[WotEver]

my circuit fills the bill perfect .....float charge for start and fast high volatage charge for domestic reduced at the captains command ........

 

So it does - I looked at it too quickly the first time.

 

Nice one

[Smelly]

If you do mind alternator surgery then source a 3 output blocking diode, connect alternator B+ to the input, the 2 battery banks to 2 outputs and the 3rd output to F+ and warning light isolating from the internal trio.

 

How would the voltage lost through the blocking diode be compensated for? My perception of this is that it would recuce the 14.37 volts from my engine alt to 13.77 rendering it of little use... Is the connection to F+ effectively feeding the regulator from the other side of the battery? Did you mean D+?

[Sir Nibble]

You have got it. The connection to F+ (ie the regulator +ve) is where the regulator senses the voltage so since that too is from the diode it shares the volt drop and hence it is compensated for. Some alternators will be more difficult than others to arrange that, yer common or garden A127 for instance it would mean removing the yellow wire from the reg and replacing it with the connection to the 3rd diode output. Many blocking diodes have an auxiliary output for precisely this purpose. You could use D+ but you would first have to open the unit and snip the field diodes, not so straightforward.

[smileypete]

If you do mind alternator surgery then source a 3 output blocking diode, connect alternator B+ to the input, the 2 battery banks to 2 outputs and the 3rd output to F+ and warning light isolating from the internal trio.

Where from, and how much?

 

cheers,

Pete.

[pistnbroke]

sir Nibbles Idea of using 3 diodes certainly gets over the volt drop problem with diodes but it does not give the faster charge of 2 alternators....the rule is you need 25A of alt output for every 100ah of bank and volt reg at 14.7v

[Sir Nibble]

sir Nibbles Idea of using 3 diodes certainly gets over the volt drop problem with diodes but it does not give the faster charge of 2 alternators....the rule is you need 25A of alt output for every 100ah of bank and volt reg at 14.7v

Yes it does, both alternators will be contributing to charging the domestic batteries until the voltage rises above the regulated voltage of the engine alternator.

 

Where from, and how much?

 

cheers,

Pete.

Off the top of my head, I cannot quote source or prices but I would imagine any auto electrical specialist should be able to find one.

[pistnbroke]

sorry sir nibbles was reading post 357 where it says connect Alternator not alternators to the input

 

 

pity its so difficult to post photo/diagrams here on this site...

[Sir Nibble]

sorry sir nibbles was reading post 357 where it says connect Alternator not alternators to the input

 

 

pity its so difficult to post photo/diagrams here on this site...

No, that's right, only one alternator, the engine alternator, to the diode input, the domestic alternator charges the domestic battery and the engine alternator is split between both by the diode.

 

Smelly,

CARGO part number 160343 up to 70A, 160399 to 120A. Both units are for 2 batteries and incorporate a third "compensating" output for the F+ connection.

[carlt]

sorry sir nibbles was reading post 357 where it says connect Alternator not alternators to the input

 

 

pity its so difficult to post photo/diagrams here on this site...

It's pretty simple, really.

 

You either link to a photo hosting site or upload to the gallery.

[Sir Nibble]

It's pretty simple, really.

 

You either link to a photo hosting site or upload to the gallery.

Unless like me your work connection will not allow you to either upload nor view pictures.

[WotEver]

Snib - I don't know these triple diodes, or how they're constructed internally. If one of the triple fails it would almost certainly fail open circuit, so would it be only one of the triple that fails, or all three? If all three, surely you're in risk of killing your alternator in the case of such failure?

 

Just trying to consider all aspects of the solution.

 

Cheers,

Tony

[Sir Nibble]

They actually tend to fail short circuit and sometimes it happens, but they're tried and tested components and I wouldn't call them fragile. The use I propose putting them to is pretty much what they are made for.

[pistnbroke]

it s not very easy to get a photo on here

1/take photo

2transfer to computer

3.. transfer to website storage

4 note down all the silly numbers

5 try to get all the silly numbers right on this site

 

 

other sites it just goes straight to the site server and thats it ...eg kia .com or boatdesign .net

 

 

would like to see a diagram of your diode set up for two alternators and two battery banks

[tomsk]

Cut and paste... 2mins max from save to computer from cam till posted. Simples.

[carlt]

it s not very easy to get a photo on here

1/take photo

2transfer to computer

3.. transfer to website storage

4 note down all the silly numbers

5 try to get all the silly numbers right on this site

Never heard of "cut and paste"?

 

You can upload photos to the gallery, on this site but why bother when transferring from photobucket to here is 3 clicks?