# Using my mower to power the house



## SolarGary (Sep 8, 2005)

Hi,
I bought a 1980 ish ElecTrak tractor -- these are electric battery powered garden mowers/tractors that GE made back in the 70's and 80's. The one I got is an E15, and it looks like this:
http://www.myelec-traks.com/E15.html
Well, right now, mine is more of a pile of rust than the one in the picture, but I'm working on it.
There is still a lot of interest and support for these old ElecTraks -- including a nice forum: http://www.elec-trak.org/

Anyway, the tractor has six 6volt 220AH golf cart batteries (as in Trojan T105's), The batteries are hooked in a series string for 36 volts total to run the mower and accessories. 

Beyond just getting it to run and mow the lawn again, I've got two solar related goals for the tractor:

Goal 1 is to be able to solar charge it with a dedicated PV panel or two. I think this is doable, and I can probably find the stuff to do it.

Goal 2 is to integrate the ElecTrak tractor battery pack with my grid-tied PV system for LONG (multi day) power outages. The idea is to basically recconnect some of the PV panels for my grid-tied system to a new charge controller that would charge the ElecTrack battery pack, and to hook up an inverter to the battery pack to power a few key house loads via extension cords. The idea is to provide power for fridge, a few lights, and the furnace (which runs on 120VAC).

This is strictly and emergency setup that would be restored to the regular grid-tie setup after the outage. It appeals to me because the ElecTrak batter pack is already earning its keep with mowing chores, and by adding a few hundred dollars worth of new stuff, it can (maybe) also serve as emergency power for the house.

The problem I'm running into is that its not easy to find a charge controller or inverter that works with 36 volts. 

It looks like the Morningstar TriStar MPPT charge controller will (probably) do 36 volts with some "custom settings" http://www.morningstarcorp.com/en/support/item.cfm?ItemId=71

But, I've not been able to find any small inverters that will accept 36 VDC as input. I would like an inverter rated about about 1000 watts or maybe a bit less.

Is anyone aware of an inverter that will take 36 VDC as input? Or, does anyone have an alternative way of providing limited AC power to the house via the ElecTrak battery pack and an inverter?

I'd like to avoid re-cabling the batteries into 3 pairs of 12 volt batteries if possible, but I guess that is one way if need be? This would allow using a 12 VDC charge controller and inverter.

Gary


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## wind power (Sep 29, 2010)

the 36v's are out there still....
Here's one: http://www.novaelectric.com/dc_ac_inverters/nova_invert36.php

As to a charge controller, you could try Glen Hurd who has a nice controller kit....if you contact him directly he might tell you how to reconfigure one of his 12/24 kits on the cheap


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## PD-Riverman (May 24, 2007)

Gary, do not know if this will help any but here is what I did on my 36 volt Golf Cart. I ran a 2 gauge positive and ground to each 2 batteries in series(bat 1 and 2, bat 3 and 4, bat 5 and 6). This gave me 3 12 volt sources that I could run a 12 volt inverter off either of the 3. I used big quick disconnect plugs on the 3 12 volt sources and one on the inverter that way I could quickly plug the inverter into either of the three. Well as time went on I wanted more power so I cut the series wires between battery 2 and 3 and bat 4 and 5 and used 2 more quick disconnect plugs on these wires that way I could just unplug the series disconnect and I would have 3 12 volt sources that I could parallel. So to give you a play by play. I would drive my golf cart to where ever I needed power. Plug the inverter into either of the 3 12 volt sources, but IF i needed alot of power for a extended time I would unplug the series plug, then I had a 3 into 1 adapter I made with the disconnects, I would plug a plug into each of the 3 12 volt sources and the other plug into the inverter that way the inverter was pulling off all 6 of the batteries(3 12 volt sources) at one time. With this set-up I could charge all the batteries on my 12 volt solar array. If I needed to drive the golf cart, I would unplug the 3 into1 adapter(FIRST--FIRST--FIRST LOL), plug the series plugs back together and drive where ever I needed. Has worked good for me for years now. 

Here is a link to the type disconnect I used http://www.ebay.com/itm/4-GAUGE-POW...549?pt=LH_DefaultDomain_0&hash=item5ae097f47d but I got them a whole lot cheaper than he has these posted.



SolarGary said:


> Hi,
> I bought a 1980 ish ElecTrak tractor -- these are electric battery powered garden mowers/tractors that GE made back in the 70's and 80's. The one I got is an E15, and it looks like this:
> http://www.myelec-traks.com/E15.html
> Well, right now, mine is more of a pile of rust than the one in the picture, but I'm working on it.
> ...


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## SolarGary (Sep 8, 2005)

Hi,

Thanks guys.

I checked on that 36 volt inverter, and it turns out its intended for military service, and has a price tag over $3000 -- ouch!
Will check around a bit more to see there is another choice out there.


PD -- that hookup sounds like it would work for what I want to do -- that may be the best way to go. I guess doing a few connects and disconnects would not be bad for the occasional time when the power goes out.
Also like the idea of having a source of 120 VAC that I can move around to wherever its needed.

Those disconnects look like a good way to go -- will have to look around for a good price.

Gary


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## SolarGary (Sep 8, 2005)

PD 

Another quick question:

Do you find that with all 3 pairs of the 6 volt batteries hooked up in parallel that you can run descent sized AC loads on your inverter?

One of the inverter sources suggested that I would be better off with 24 or 48 volts, but there is really no sensible way to do that from the six 6 volt batteries. I can keep the 12 volt side cables short and large -- seems like for the modest loads I have that the 12 volts should be OK?

Gary


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## PD-Riverman (May 24, 2007)

Gary I have alot of different size inverters. If I am going to run a circular saw or electric chain saw I will usually grab the 1500, but If i am going to run a chop saw or decent size air compressor I will get the 2500 or 3000. The bigger inverters have 2 negative and 2 positive hook-ups. If I know I am going to be drawing Alot then I will plug in both inverter wire hook-ups into 2 different battery sources-------You know I stated that I would unhook my series plug on my golf cart then plug the 3 into 1 adapter and plug it into the inverter-----works good on the smaller inverters-----but if I am using a big inverter pulling heavy loads It will work better pulling from 2 different 12 volt sources (keeping in mind the big inverters I have, have 4 wires 2 + and 2-) than it would with just one of the inverter wires hooked into my 3 to 1 adapter. 



SolarGary said:


> PD
> 
> Another quick question:
> 
> ...


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## Windy in Kansas (Jun 16, 2002)

I'm a little jealous as I have read about the units and actually looked online for one for awhile. Seem to be snapped up as fast as they appear which is rarely. 

Thanks for this post. I remember seeing what I thought might be one about a month ago and meant to stop and ask about it the next time by. Forgot all about it. Might be worth a 40 mile or so round trip just to find out. I don't need it as a mower now as I bought one, but one would still be nice to have for farm errands.


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## wind power (Sep 29, 2010)

Picky Picky Picky:hysterical:
Seriously:
http://www.amazon.com/Tripp-Lite-APS3636VR-Inverter-Automatic/dp/B00006HO5G
Probably the most economical thing to do would be to buy a cheaper 12 volt inverter, and disconnect all your batteries, then have a seperate set of cables to string your batteries for 12 volt....keep an eye out so as not to have them unbalanced as they discharge.


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## SolarGary (Sep 8, 2005)

Windy in Kansas said:


> I'm a little jealous as I have read about the units and actually looked online for one for awhile. Seem to be snapped up as fast as they appear which is rarely.
> 
> Thanks for this post. I remember seeing what I thought might be one about a month ago and meant to stop and ask about it the next time by. Forgot all about it. Might be worth a 40 mile or so round trip just to find out. I don't need it as a mower now as I bought one, but one would still be nice to have for farm errands.


They are hard to find -- it took me over a year and that was with some help from a guy who is very active in the ElecTrak world. Most of the ElecTraks that do come up are out east and that was too far for me to drive.
Putting a permanent search up on ebay, and checking at the ElecTrak owners site http://www.elec-trak.org/ will bring up some leads.

If you find one, have a good look at it, as they vary a lot on condition and accessories. The one I got was still running, but it has a lot of rust -- I've got about a couple full time days into dissassmbly, scraping, cleaning, and painting stuff -- still another day or two to go. The nice thing is that they are pretty simple and a lot of the parts are still available.
Just ordered a new set of batteries -- which were more than I paid for the tractor, snowblower, mower deck and blade! Its been a fun project so far.

Thanks for the lead on the TripLite.

Gary


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## SolarGary (Sep 8, 2005)

Hi,
After a lot of mental back and forth, I ended up ordering the large TrippLite 36 Volt inverter that WindPower found. Its a bit of a beast at 55 lbs and 3600 watts, bit it gets good reviews. 
http://www.amazon.com/Tripp-Lite-AP...HO5G/ref=sr_1_1?ie=UTF8&qid=1314922073&sr=8-1

The scheme of using disconnects to make the 36 volt pack into three 12 volt packs was very tempting, but for better or worse I went with the 36 V inverter. The TrippLite also has a good charger which I need since the original charger was lost.

So, now I'm trying to decide on how exactly to solar charge the 36 VDC pack from my reconnected grid-tie PV array for long power outages. I'm thinking that the Morning Star Tri Star MPPT 45 amp controller would be good. Its one of the few that will do 36 volt batter packs, and it seems about the right size. From running the Morning Star string calculator, I'm thinking of using 6 of the grid time PV modules recabled into two string of three panels each.
http://www.morningstarcorp.com/en/strings/calc.php

Does anyone see why this would not work? Or, have a better solution?

I was thinking about also doing a standalone solar system of a couple panels to charge the tractor, but after thinking about it, I think it makes more sense to add the panels to the grid-tie system where their output will be used all the time?

Gary


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