Author Topic: Charging a 12v battery  (Read 1307 times)

Johndoh

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Charging a 12v battery
« on: June 06, 2018, 01:52:22 PM »
Well guys the generator is up and running currently on a pull start. I have a starter bits of wire etc to connect it up however the rectifier is missing. The generator has 12v, 115 and 240 v outlets can I simply use the 12v outlet to keep the battery charged? I would like it to start electrically for the missus. Thanks
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ajaffa1

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Re: Charging a 12v battery
« Reply #1 on: June 06, 2018, 02:07:40 PM »
Hey Johndoh, Well done for getting your generator running. I think we need a bit more information before anyone here can give you useful advice, a picture tells a thousand words. Missing rectifier? is this on the DC/charging side of things or is it a rectifier used to feed the field windings to generate AC?

Bob

Johndoh

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Re: Charging a 12v battery
« Reply #2 on: June 06, 2018, 03:12:14 PM »
There is a coil under the flywheel with wires coming out of the side of the engine. There is supposed to be a rectifier there (photo attached) but it's missing. There is also a 12 v outlet on the control panel I assume its working as the 115 and 240 parts are working. I would like to use this to charge the battery if possible. The whole machine cost 50 and a rectifier is 60 that goes against my Scottish 1/3. I'm getting about 3 volts from the coils

« Last Edit: June 06, 2018, 03:19:11 PM by Johndoh »
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EdDee

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Re: Charging a 12v battery
« Reply #3 on: June 06, 2018, 03:38:12 PM »
Hi JD,

Mine also went legs up....I have never replaced it (Also probably a hybrid Jew/Scot in my past).... Instead of using that, I just have a small battery conditioner/charger hooked up to the mains permanently....

Regds
Ed
12/1 750RPM/9HP Roid 5kVA- WMO Disposal/Electricity & Hot Water Gen
12/1 650RPM/8HP Roid 4.5kVa - Demon Dino
Chinese Yanmar - Silent Runner with AutoStart
Classic Komatsu 1963 Dozer/Fergusson 35 Gold Belly ...
Bikes,Cars,Gunsmithing & Paintball...Oh yes, a 5Ha open air Workshop to play in!

Johndoh

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Re: Charging a 12v battery
« Reply #4 on: June 06, 2018, 03:43:44 PM »
That would work! Somewhere in the shed is a booster pack from Aldi or Lidl that would work ?
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EdDee

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Re: Charging a 12v battery
« Reply #5 on: June 06, 2018, 03:54:05 PM »
Not sure JD.... Don't know the units personally... Hit Goog university for some info!
12/1 750RPM/9HP Roid 5kVA- WMO Disposal/Electricity & Hot Water Gen
12/1 650RPM/8HP Roid 4.5kVa - Demon Dino
Chinese Yanmar - Silent Runner with AutoStart
Classic Komatsu 1963 Dozer/Fergusson 35 Gold Belly ...
Bikes,Cars,Gunsmithing & Paintball...Oh yes, a 5Ha open air Workshop to play in!

Johndoh

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Re: Charging a 12v battery
« Reply #6 on: June 06, 2018, 04:24:45 PM »
rectifier on amazon UK for 13. I did a little research and the 12v outlet on a generator isn't regulated so it wouldn't take account of how much charge is in the battery. The Aldi booster is supposed to start a 2.0 diesel car it will need to be charged for testing as it's not been used in years. Really the rectifier charging a small battery from the coils would be best as easier for the missus to operate. Just changeover switch, start the generator and count to 100 before throwing up the breaker.
It is better to light a candle than to curse the darkness

glort

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Re: Charging a 12v battery
« Reply #7 on: June 06, 2018, 11:32:30 PM »
Just changeover switch, start the generator and count to 100 before throwing up the breaker.

No no no my little green friend with kilt wearing tendencies! Let me show you the way of the people who hunt with bent sticks and revere giant coat hangers in the middle of their city!!

First you need one of these coming from the output of the coils of your engine.

https://www.ebay.com.au/itm/Rectifier-with-3-Phase-40A-1000V-Diode-Bridge-SQL40A-B9C9-T8U2/282694114161?epid=722902786&hash=item41d1e1db71:g:vaYAAOSwETJZ7-Fw

This is a rectifier and will turn that power ( usually 3 Phase) into DC output. If there is only one wire connect it up or get a single phase rectifier if you want. Not much difference in price so I tend to keep the 3 phase ones on hand.

Then one attaches one of these little beasites from the land of " How in the fk that make that shit so cheap??"  from the rectifier and to the volt storage Devise.

https://www.ebay.com.au/itm/12V-24V-6-60V-Battery-Charging-Control-Board-Charger-Power-Supply-Switch-Module/263472348069?hash=item3d582cfba5:m:mk4SL-1weHX9LrCwt2tcPRA

One then takes their Multimeter and Monitors battery connected thereto and sets the little screws with GREAT Precision ( they are incredibly touchy little buggers) to get the charge level thou desires. For a 12V battery my personal preference  is about 14.5V but look on the battery you are using and see what the guy that made it prefers. The output from the controller is supposed to be 10 A. Seems optimistic but then again, the 12V output from these Gennys is only ever 8A usually anyhow. More than enough to charge a battery.

This should keep Thine wife happy and the leprechauns pot of gold not depleted!

You can see in the listing there are also modules that run off 220V input so if your 12V output is not working, you could just tap one of these off the 220V side. Do remember it's 230 Though and put it in a little plastic Box and insulate the damn thing though.

I bought a ride on mower some months ago from a dealership that had traded it and Claimed it wasn't going and they didn't have time for their mechanics to work on it.  Yeah right, they'd worked on it plenty as evidenced by the new wiring, connectors and parts.  Took me 15 Min to get it going and 10 Min of that was sitting here looking for an online wiring diagram.  Motor is perfect, would not have believed it could be so good but wasn't charging either.

I applied the above components in leiu of the OEM controller which was more than I paid for the whole mower and Bingo! I have battery Charge!
Of course my plan is to put and 80A alternator on the spindle so the thing will be a mobile battery charger and also run lights etc with a Spare inverter I have for 230V as well as 12V LED light bars.

Let us know how you go with it.

Johndoh

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Re: Charging a 12v battery
« Reply #8 on: June 07, 2018, 12:17:30 AM »
Thank you for the information Mr Glort to be honest I'd rather talk naked about erectile dysfunction to a bunch of nuns than attempt electrical repairs.. I know my machine has a bridge rectifier but I have no idea where the wires go. I assume if I attach this

https://www.amazon.co.uk/gp/product/B077RFN4PZ/ref=ox_sc_act_title_1?smid=A10C9AX1J5P100&psc=1

connect the plug and run the other wire to the battery it will charge said battery?
It is better to light a candle than to curse the darkness

mikenash

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Re: Charging a 12v battery
« Reply #9 on: June 07, 2018, 12:45:28 AM »
Hi JD,

Mine also went legs up....I have never replaced it (Also probably a hybrid Jew/Scot in my past).... Instead of using that, I just have a small battery conditioner/charger hooked up to the mains permanently....

Regds
Ed

In our line of work we have customers with older gensets that have inbuilt 12 VDC chargers.  When they fail I just buy a good-quality off-the-shelf battery charger and hardwire it into the 230VDC leg and attach to the battery.  That has always been a simple, cheap solution

glort

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Re: Charging a 12v battery
« Reply #10 on: June 07, 2018, 06:31:12 AM »
I assume if I attach this
connect the plug and run the other wire to the battery it will charge said battery?

I don't know,  have never seen your genny but if it looks like the plugs will fit then the chininglish description would suggest it may be what you need.
Most of what I have done involved swapping the AVR's which was mainly plug and play anyhow.

I have the electric start engines these are supposed to be for but never really looked at the setup.  Never really run the engine for any useful work come to think of it.  Just sitting in the corner of the shed with the other 3 looking pretty.  :0)

Not a lot of Money so may as well give one a go unless the more knowledgeable here can see something problem with it.

Johndoh

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Re: Charging a 12v battery
« Reply #11 on: June 07, 2018, 01:10:25 PM »
I found the wires coming from the bridge rectifier they ens in 2 wires one red one black on a volt meter they read 25.2 volts. Looking through the little box of parts that came with it there is a little electronic box of tricks and a load of wires attached but what they do is beyond me. The 25 volts is DC so I am thinking it could be reduced to 14 ish and regulated???  This is the part where I stopped trying to figure it out and fitted my new exhaust. It's bearable! no louder than the Yanmar L48 so I'm happy enough with that for now. I know a lot of you guys find electrics as challenging as patching an inner tube, I can do the tube this is beyond me. I downloaded the manual and wiring diagrams for this engine, it's like trying to read Sanskrit in the dark wearing sunglasses.
It is better to light a candle than to curse the darkness

glort

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Re: Charging a 12v battery
« Reply #12 on: June 07, 2018, 03:59:44 PM »

If the wires are coming out of a bridge rectifier, they have to be DC. That's what a rectifier does, converts AC to DC.
25V is too low to be charging a 24V system unless they had a boost circuit which would be highly unlikely. Therefore it must be 12 which is what these things usually have an output for.

As this is the raw DC, You'd have to find the input wires on your regulator and hook them up.  If this thing is from the original genny the other wires could do all sorts of things. Go to a panel meter, energize fuel cut off solenoids, low oil shutdown.... all these would operate at low Voltage.

Wiring Diagrams can be a handful so to speak but if you follow the numbering and codes shouldn't be too hard on something simple like this.

Johndoh

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Re: Charging a 12v battery
« Reply #13 on: June 07, 2018, 07:11:35 PM »
So I'm back to the beginning. for the moment I will ignore the bridge rectifier and concentrate on the coils (dynamo) under the flywheel that connects to the 12v charging rectifier. I checked and the coils actually put out 25v AC would this be correct? does the rectifier convert the power to 14v DC? do I need to connect anything between the rectifier and the battery? Should I stick to the pull start?

It's all academic now as I have the wrong starter it's off a Kubota garden tractor and useless. Rope start it is and rope start it will remain!
« Last Edit: June 07, 2018, 09:24:06 PM by Johndoh »
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glort

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Re: Charging a 12v battery
« Reply #14 on: June 08, 2018, 01:32:06 AM »

Just in case you ever do want to get the 12V out..... :0)

The rectifier changes the AC output ( all Alternators output AC)  to DC. In the process the DC is I think from Memory 30 % higher Voltage because of the rectification and the funny way electricity works etc.

A REGULATOR is what changes the incoming power from this to that.  On a generator generally you will  find the incoming power has to be a higher voltage or at least potentially, that the output.  There are buck and boost  regulators  that you could feed 6V or 30V into and still get 13.8 or whatever was Above and below the target voltage but generally ( if ever) they are not on the sort of generator we have and are more limited to low power electronics use or things like  UPS systems.

You would put a Regulator like the one I or you linked to.  This will try to raise the battery voltage to the target point, 12V 13.8, 14.5, whatever it's set to, and keep it there. When a load goes on the battery it will pump all the power it has to the battery to try and keep it from discharging. In this case I would think 8A. If the battery is below that it will keep pumping power gradually tapering off till the battery is " Floating" where the reg wants. At this point it might be only putting in a couple of hundred Milliamps.

If you anted to do some clear pics it would be muchly helpful in guiding you with this. there is no set way of doing it and flying blind makes it difficult to see what going on and what you have and needs connecting.
I'm not trained in any of this stuff, I have just assed about enough to have an idea of what I'm looking for and can work the rest out with a multimeter.

Now you are going to be another one that distracts me and gets my mind wandering!  All this generator and Rectifer talk makes me want to pull out my induction motor and wire up all the caps and rectifiers to turn it into a generator again.  I loved playing with that. Seems it loves me too as it didn't kill me when I gave it every opportunity a while back! :0)

It's bit small for what I want though, I learned that I can only really expect to get 2Kw out of it and that's not enough. There is a 20Hp on fleabay I made an offer on and I should be able to pull a health 5Kw out of that which would be much more satisfactory.

You should get yourself a 3 Phase induction motor mate and set it up as a generator. You could learn about Star and delta wiring, Capacitance, flashing field windings, frequency, AC/DC, 3 phase Rectifiers, voltage sag, C2c configurations.....  About 3 years since I have had a play with my motor, I have probably forgotten more than I remember now.  That happened last time I got it out. Couldn't remember how I did something and found the answer by looking it up..... and found one of my old YT Vids where I had done it before!   :embarassed:

I'm getting all excited  thinking of this stuff now. Have to go watch some generator porn on YT!
Not a lot of people seem to do much with induction motor generators though it seems.
 Pussies!!  :0)