Simple generator start

[Jedon]

I have a 48V battery bank and a Lister SR2 with a starter hooked to a 12V battery ( no alternator... ) with a contact switch.
I would like to be able to start this generator with a relay and not have it hooked to that 12V battery that doesn't get charged.
Ideas?
My Xantrex SW+ 5548's have generator support but I think I need a module ( $300? ) or maybe I can just come off a pin on the RS232 port and put a relay on?

Thanks!!
-Jedon

[dubbleUJay]

Hi Jedon,
I dont know the Xantrex at all, but the module is probably just a auto engine controller with remote start capabilities. The Xantrex sends a signal to it when it needs power.
I would think that any engine controller would work, but you do need one, you cannot just connect the start signal from the inverter to a relay to run the starter, the inverter does not no when the engine is running to stop the starter, that's the job of the engine controller.

Hope this explains it,
dubbleUJay

[BruceM]

Nice job WJ. 

Jedon, You'll be over $300 building your own unless you're a good scrounger and your time is worth nothing.  Or you want a hobby project.

If the Xantrex unit will do the job, go for it.

[Jedon]

Would I hook the GSM right to the starter? Wouldn't think it could take the amps.
I guess going from 48V to 12V is too hard/expensive and I should just put a battery charger on a 12V battery to start the generator?

[BruceM]

Its going to be cheaper to go the 12V battery route, I suspect, but you may be able to find a buck converter to get your 48V down to 12V.  Measure your starters peak current first.

Here's one:  DCDC10032-12, http://www.zahninc.com/sd11.html  The 32amps output may not me sufficient, check your starter.

Perhaps some googling will find something suitable.

Bruce

[veggie]

Jedon,

Not sure if this is what you need, but take a look.
This is a diesel generator start controller for under $200.
I picked up two of these for my projects.
The unit runs on 12 volts and sense 120vac from the generator so that it knows when the unit has started.
Also has contacts to drive a solenoid and kill the fuel rack if a shutdown is required.

Drawings and manual are available on this page...

http://www.mtspowerproducts.com/html/mcp_products/engine_controls/ECU-04.html

Cheers,
Veggie

[BruceM]

Great product find, Veggie. This could be a big help for some folks.

I could even use it for my air start system.  The only thing lacking is engine monitoring/emergency shut down.

Bruce

[veggie]

Bruce,

I had the same thing in mind for my air start system.
Have the module open an air solenoid when it gets a START signal.
Once the module senses 120vac, it opens the solenoid circuit and the air motor retracts.

Veggie

[BruceM]

The outputs are rated well above the solenoid currents (1 amp for small volume solenoids, 2 or 3 for the large flow types needed for the starter motor), so that should not be a problem. 

On my air start system the starter is stopped as soon as engine rpm starts to climb above a certain point. I don't know about waiting until 120VAC shows up. The ramp up of rpm on my 6/1 is fairly poky.

For anyone who wants it, you can have the Picaxe basic code for my engine controller/monitor.  A Picaxe chip with logic level gate mosfets will do the job.

If you need help modifying it for your use, within reason I will help.
The bottom of page 7 and top of page 8 is the start routine.

[Jedon]

Got a reply from Xantrex:

Dear Jedon Thompson,

The GSM and ALM which are identical and were used with the SW Plus have been discontinued and are no longer available.

The XW AGS will not work with a SW plus.


Regards,

Xantrex Technical Support
Customer Service Operations
Xantrex Technology Inc.
Email: customerservice@xantrex.com
Website: www.xantrex.com
t: (360) 925-5097 / (800) 670-0707
f: (360) 435-2636

[TimSR2]

Could you not use  12v directly tapped  off the 48v bank for starter service? This is such an intermittent load that the imbalance would not be noticeable. Unless your battery bank is located far away then the cable length would be an issue.

I have installed a GM 10SI alternator driven from  the 900 rpm camshaft extension, 7-8 inches diameter  will get you the 2000 rpm minimum cut in speed you need and keep your SLI battery topped up. Fairly easy project, and the start battery, pulley and belt will be less than $300

Tim

[Jedon]

The battery bank is about 16 inches away from the SR2, how would I wire that up? Just come off two 6V?

[TimSR2]

Exactly!  I assume the 48v battery bank is now isolated from the engine and fed from a charger ?

Earth the negative post  of the negative end of the 48v bank to the engine frame, and take 12 volts off the positive post of your second 6 volt battery. If you have Golf cart batteries they will have enough power to crank your engine all day.

Some older golf carts  and electric utility trucks like the Cushman Turf Truckster used to use a speed controller that used 3 steps; 12v, 24v, 36v for full power. It was just a big 400 amp wiper switch. They tapped off the battery pairs to get the voltage for the speed they needed. This caused problems for the  batteries over time due to unequal load and they had to be rotated to compensate. In your case the intermittent start service is such a negligible load that there will be no ill effects.

Tim

[dubbleUJay]

Jedon, this seems all good and well, but 1st I suggest you just hook it up temporary and see what your inverter does when you crank the engine and it sees a voltage drop from its batteries for a few seconds Maybe nothing!
As Tim was saying, the A/H depletion on those two cells shouldn't be a problem, but if it was me I'll still look for a pair of 12V automotive batteries with a trickle charger to use as a control battery source for things like starting and electronic/electrical controller stuff you might have or get in the future IMHO.

It takes one "cell" in a battery array to stuff up the whole lot I believe.

One other thing, I don't know your inverter, but your negative supply from the battery is not floating on the inverter side, but also connected to "earth" I hope?
I'm just afraid for a potential difference between the engine frame and the inverter chassis!
I think Tim can help out here if he knows the equipment?

[Jedon]

I have 16 Trojan L16H batteries so the amp drain should be not noticed I imagine.
The inverters are 2 Xantrex SW+ 5548's, the positive and negatives are hooked into the inverter through a DC breaker, the inverters are grounded and the AC is grounded at the house.
I have a car battery hooked to a 10A manual charger which is probably too much juice, I run the SR2 about 5 hours a day. Every couple of days I use the charger to charge up other batteries instead. I'll keep an eye out for a better charger that will do 2A auto and just keep it plugged into the generator output, that should work.

I still don't know how to set up the relay to start it remotely though, I have a board that will trigger a standard 12V car relay and I have a handful of relays but the switch looks like a simple contact switch so handles a ton of amps which I'm sure the car relays won't handle and high amperage relays are $?