building a 12 voltbattery charger

[glort]

Bob,
These alternators I am using in both the Mitsis and the Bosch units will continue to charge when the field is disconnected.  The voltage output drops slightly but they do continue to pump out the amps unless the field wire is shorted. Even when you do that, if they are still connected to a battery, they will come back on charge after a various while depending on battery voltage, load and RPM they are running at.

I'm wondering if it might be better to use the temp switch to control some relays on the output rather than the field? If you left a small load like a 55W light bulb connected at all times so the thing wasn't just going open circuit then crashing back to full power again, this may prevent problems. Not sure what they would be but I -think- this may be better than leaving them go with no load at all.

Relays are cheap and something else that gets thrown out at the wrecking yard ( along with the wiring loom and fuse/ relay boxes) so it wouldn't be any big deal to wire up 3 or 4 of the things with maybe another to control the power switching of the relay gang from the temp switch.

I'm very interested in what sort of testing might be done to prove these alts one way or the other.
Would as I proposed, running the things overloaded for like 6 hours prove anything about them in your or other off gridders minds?  Is this a long enough test or to have any meaning, would they have to be run non stop for a week or.... Just trying to determine what needs to be done to give people some faith ( or not) in these things and qualify them as a suitable ( if not terribly efficient) power generation unit.

You mention derating the things but if like I say, I drop on a load that is well over their capacity and run that for hours on end and max the end temp out and hold it there, is this going to be an indication of their longevity and robustness or do they need to be cycled over periods that are impractical to test other than in real life?
Is there any other torture test you can think of?
I'm quite keen to see what it takes to break on of these things because then we should have a limit established that we know if we keep under, problems should be avoided.

If anyone in Oz has a battery bank and a motor they could couple one of these alts up to, I'd be happy to send them one so they could hook it up and see if they could break it or how long it took.  When/ if the thing failed, no big deal, just go back to your regular power source and have saved a bit of wear and tear that was taken up by the  test alt.

I have run these things for a couple of hours flat out and they did get stinking hot so I have faith in their ability to survive. What I'm wondering though is what sort of time frame the off gridders would want to see in testing so I could say " these units are ok and won't burn out at full load" and base that on testing that is creditable to people.

[SteveU.]

Morning guys.
M.Bob those welded lead Delco alternators you refer to were thier "CS" series. The ONLY units put out in general service as comparably weak were the late 60's, early 70's Hitatchi's with diode and rear bearing pocket problems; the same era Lucas plastic rear covered alts with the sandwiched plate stacked retifiers with an even worse diode failure rate; and then the 80's Ford units when they went from been used since day one threaded stud eye ring terminals to an assembly line  robotic arm possible connected al'la failed DIN style plug in output termination. Lots of underhood fires from these. All of these I could ungrade in some fasion to get under a 2% actual in-service failure rate.
The damn CS's though the problem was the heat problems buillt into the design. GM/Delco had moved the now higher amp/higher heat rectifier in from the unit edge  towards the center and then wrapping it around the rear bearing pocket focusing heat onto this area. At the same time the switched from thier aways been used heat expansion tolorant rear floating needle bearing to an under sized rear ball bearing. Not enough provision was made for this bearing to be able to in pocket float with the rotor lenghtening and shortening from heating and cooling. SAME classic mistake Ford made on thier double ball bearing 50's/60' genrators, And those 60's/70's Hitiachi alts. The solution was in  the GM experience history on thier 40's,50's,60's double ball bearing genrators and early truck and industrial alternators. But easy to see that THOSE engineers had retired and the new guys were working out componet design guideline charts and had no actual in field expereince with their own products let alone other manufacturers failures. MY solution to these as a rebuilder after a couple of years of headbeating a 20% comeback rate finally became to just supply factory GM/Delco "Remanufactured" units that were ussally new anyhow straight off of the robot lines and let THEM eat the warrantee comebacks. I had to do the same with their terrible PITA aluminum field coil, thin mylar insulated, screwless press-in fold tab retained 80's GM/Delco robotically assembled 5MT starters. throw-a-way junk.
First: three genrations of "world changing" higher failure rate Delco Freedom batteries -> then aluminum starter field coils -> then the 5MT starters and CS alternators convinced me that GM/Delco had lost thier design to be better engineered 30's through 60's edge and listened too much to thier own stihck that they were "General Motors. The largest Corperation in the World". R.Bosch didn't buy that speel and just kept evoled into the silicon diode era better and better. And by the late 80's Nippondenso shook off thier Bosch licence beginnings and evolved better, more durable units than Bosch themselves.

glort oberve that these internal dual fan units have biased fan blade pitches. This makes then ~10-15% better cooling in the design rotation direction verus a bi-directional straight radial pitched bladed fan. Means you spin them backwards from design intended and they will cool 30% worse!! Careful on your loan-out installs. And a double fan Nippondenso alternator with a larger area spread out epoxy dipped rectifier  will run cooler and be more durable than a heat concentrating raw aluminum small finned "GM" style rectified Mitsubishi or a heat distorting thermal plastic bodied rectifed R.Bosch.
As always - using what you got, or can get readily always starts out with a 2X, 3X advantage better that what you'd have to buy out and have shipped in, in my opinion. Just obtain more of the local and swap out as needed for the best in-service operations bottom line costs.  Remeber; DYI your labor is your "Free" advantage. Use this to your benefit.

North American guys in addition to the Nippondneso units off of the Dodge/Jeep/Chyslers since the early 90's; the 90's and on Ford production 3G and 4G dual internal fan alternators are tough, tough units with long life brushes and easily converted to off board regulation without having to crack the cases to hack into. There were many reasons that both GM and Chrysler went 2000's backrupt and Ford didn't. Consistently working, engineering,  and especially self-critically striving to do a better job was a large part of this. Make the product that the in-field users can use/abuse and and recognized as tougher and more durable and they will want to come back for more will always win out over in the end. Ha! Ha! Not that Ford is perfect. I finnaly put a sheet metal screw straight thorough the push on starter mounted shifting solenoid activate therminal that exhaust manifold heat kept migrating off after one time too many laying out in the cold rain! Parts stores now have an upgrade kit for this. And Reman units are supplied this way. Screw threaded closed loop eye ring terminals are still the best for field service conditions!

Regards
Steve Unruh

[glort]

So, anyone come up with a torture test to convince ( or confirm) the disbelievers as to the potential of these alts standing up to charging battery banks?

I went up the shed and dug out all my 12/240V inverters today and fixed some dodgy leads etc and tested them so they are all ready to go.
I have about 2500W worth of 240V power plus the 15% inefficiency of the inverters themselves.
Only concern I have is possibly " Balancing " the load so the alt is overloaded but not so much as to create too low a voltage where the inverters sense it and drop out.

It's going to take a lot of headlight bulbs or  radiator fans to pull down 11-1200 watts on the alt without using inverters and I'm having trouble coming up with any other sort of 12V dummy load I could use.
I may be able to use a couple of metal plates in a solution of salt or caustic as I have done before but keeping that from boiling away over the time I think the test is going to take could be an issue.

[BruceM]

Hey Glort,
I just read your note about the alts you're using charging with field disconnected.  You will need to remove the regulator circuitry entirely on these, as they seem to be a self exciting design much my MB alternator regulator.  Once the '85 MB 300D alternator spins fast enough, it will turn itself on without any external excitation.  On my car that was at 3000 rpm.

Or perhaps I've misunderstood.

[glort]

Nope, you understand Perfectly Bruce.
That's exactly what they do.

Only difference I can see with the field connected is they put out a slightly higher Voltage.  If the field is disconnected and the output leads dead Shorted, the thing will stop generating. Sometimes if the RPM is fast enough they will come back up and sometimes maybe I haven't been patient enough to wait and just reconnected or flashed the field wire.

Digging around up the back yesterday I came across a Hitachi 24V alt I bought a while back to use to charge batteries I wanted to run a UPS from. Looking at it, I'm not sure if it is an externally regulated type.  It has a large " A" terminal ( Wires)   and the wiring looks a bit unusual. It has wires coming out from the unit itself  and I suspect the 2 heavy white ones a re the output rather than a bolt terminal I am used to seeing.

I was wondering if there was any advantage to the old type Regulators over the built ins?
I have never played with the old external type regs and I'm not even sure if they were only for generators or early alts came with them as well.
If there is some advantage to them, does anyone know if they could be hooked up to a modern self regulated alt and if there would be any advantages going that way?

I picked up my New 13 HP Petrol engine this afternoon. I'll get  a couple of alts from the car yard so when I get back from the work trip in a couple of weeks, I can hook one up and perform a " Try to Fry" test and then maybe a dissection or Autopsy. I'm pretty sure I have a sizeable pulley up the shed that will fit the engine so I should be able to put plenty of spin as well as load on the alt.

I might try and get one of those infra red Thermometers to see how hot the thing runs as well.

[egbert369]

Fella,s- Thanks all for your replies and apologies for the delay in getting back.
I,ve only just received the Sterling regulator,When I can get someone to help me post photos and diagrams I will post some of the information from the information manual to give you and/or any future potential users an idea of it,s specs.
Can tell you that it will accept up to 120 amps without the internal alternator reg or 300 amps when combined with the alts original regulator.
#Is a 3 stage reg also with Equalize function if reqd.
#Has soft start ramp up.
#Has a number of safety features and cutouts.
#Pre set battery selections.
Basically,It does what a good solar charge controller would,except from an engine driven source.I,m a ways of building and using this unit so cant yet testify any information in a factual way,However I have researched a number of English sites whereby people with campervans and starter/house battery bank setups have extolled their abilities and durability.
On another note-I,ve decided against using the 13hp Kawasaki as it,s been a great gennie in the past so I,ll investigate the option of having the actual generator output problem solved/fixed.
I can still run drills,grinders fine with it but there is still some problem existing with it that's outside my electrical abilities.
So the the options am looking at now is to make use of the 2 cylinder diesel engine in my small Kubota tractor(either straight via the engine,or,via the gearbox and pto shaft(given the occasional use-Whats your thoughts on this?)
Alternatively-get a 4-6 hp motor for the job.
Glort,I like your ideas with the alternators from the wreckers, What area of Oz do you live in mate? I,m in the Gippsland area of East Victoria-Be good to catch up and bounce ideas!
As mentioned by one of the other blokes here regarding battery bank size and charge acceptance-It,s 875 ahr,s of Yuasa Agms.Hav,nt really been able to find information on max charging capacity (ie:10-40%), So am figuring on 20% being a safe margin to work on,given I only really want to work on the bulk charge at this stage.
To all those that have contributed-Thanks again

[glort]

Hey mate,

I'm from Sydney. I tend to go north rather than south but if you are ever up this way would be great to catch up. If you want a couple of alts, let me know in advance and I'll grab some for you.

Doing some real rough calcs, ( rough being the operative word) Your battery bank should come up from dead flat in a max of 8 hours using 2 80A alts.
I'm factoring in a 50% extra charge rate as batteries  don't work on a 1:1 charge factor and derating the alts a bit to allow for any possible losses.  Of course if you were only taking your bank to half depth the time would be less and you could also use the charger whist drawing power off the bank to compensate what you were drawing off.

150A would be a bit under 20% charge rate so should be fine.
You could go a 4 Hp engine and run 1 alt with of course lower charge rate and longer charge time or if your controller has the ability to determine charge rate, maybe run 2 alts at say 50% output which would well and truly put pay to any overheating concerns.

Depending n the hours you might run this, I think i'd be sparing the Kubota engine and looking at something else.
You can get china Diesels off fleabay for about $5-600 and there have been a variety of used Diesels come up lately. I saw a Hatz 1B20 go for about $150 last week and I think it was down your way. all the good engine deals seem to be in Vic from what I have seen! :0(

[egbert369]

Thanks Glort,I,m going to check out a few Jap auto wreckers here in Melbourne,The going price seems to be around $4o-$60 an alt from enquiries.
A mates got a couple of second hand Chondas I can play around with,not sure of their exact status or condition at this point.
Happy to do the experimentation with scrounged gear for now and iron out the bugs.Curious as to how you synch the 2 alternators together in your setup.Not sure if this Sterling Pro reg B would allow it or not?Whats the rated amp output ability on the average modern Japanese auto alternator?
Thanks,Andy

[glort]

$40-60 seems to be about the going rate for alts depending on what they are off.

The amperage seems to be around the 80-100A mark. I think some of the newer commodore alts are up to 200A and a lot of them are 120 -150 from what I have seen.
Same with Falcons and they all use the same style 2 internal fan alts.
The alt on my Diesel patrol fell over on the weekend. Was putting out 18V them pop, nothing. I was 2.5 hours away from home so I was glad it let go. wouldn't have wanted 18V for that long.  That's why I love big batteries. You can be 200KM from home, at night and still make it with enough battery to kick the thing over in the morning.   

Unfortunately the alt on the truck has the vac pump at the rear so I can't swap a Suby one over. I had a spare alt off the old truck so I threw that on for now and will have a look at the old one in the next couple of days. It' doesn't look too old so I'll have a look inside and hopefully it just needs a new reg and will be fine. From the outside it looks like another Mitsi alternator and the reg, what I can see of it, looks very similar to the ones in the suby alternators. I wonder how lucky I can be??


I don't use an external reg on the alts so I just have everything, the field and sense wires and the output coupled all  together. Works perfect.
I was going to wire them up properly so I can have one or the other alts in and was even thinking of putting a diode in the sense wire I can switch in and out to get boost voltage/ amperage if I want.

It would seem to me you should be able to parallel  your alts on the controller as well. It should just taper the voltage to suit and balance the 2.
I looked at the site and can't see a lot of detail on the things. How do they control normal self reg alternators? Do you just wire the field and sense wires into them and they do the work or do you open the alts up and tap into them somewhere?

With the engines you are going to drive/ test these with, I have used 6" pulleys on the stock alt drives.  I see on the web a lot of people talk about using 1:1 or smaller but that has been far from necessary in my experience using 5HP petrol and Diesel engines.  I prefer to over drive them to keep the revs and the noise and wear on the engine down.
I have also read people say that you need to run the engines at rated RPM for cooling and lubrication but that also has not been my experience. Far as I am concerned, the slower you can run them without bogging them down the better.  Less wear, noise and if you look at automotive engines, they run them slow and torque them up for fuel consumption.

It would be good to see how you go running your alts flat out on the controller. If connected to your battery bank it should be easy to take off the current with the 240V appliances running.
A fan heater would take care of that! :0)