# What does this mean? Will it work?



## Guest (Mar 8, 2010)

Heck the battery weighs about as much as the tractor 

These are built for stationary solar setups. Kind of heavy for a vehicle. It could be used. If you can put in two you'd have a long lasting 24 volt system. I'd say they are too big for your project. Others may chime in on this one. 

Pete


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## Jimdear2 (Oct 12, 2008)

Woody,

That's 180 English pounds for 360 pounds of deep cycle gel cell battery. That's a lot of money for used batteries. Especially since you don't know how old they are. Used gently originally they might be good for years yet, but who knows. Marathon batteries are supposed to be preimum quality though.

As I understand it, gel deep cycles will supply medium amounts of power for a Loooooooooong time. Even overvolting that little motor I think you will have the Energizer Bunny for a co-pilot. With batteries like those, you might be able to get a DC to DC and inverter and run electric tools and saws, you might be able to power accessories or mower decks, or snow blowers and still get extended use.

One thing to look at is intended use, four of those batteries would probably run the tractor for hours puttering around a yard or garden. They would also, with an inverrter, make a decent UPS for your frige in a power outage.

For myself, if I was building the tractor thingy I would buy them, But then I do all kinds of insane and stupid stuff, without realy thinking it through, usually, to my detriment. Just go look through my junk pile.

The weight part is imaterial when used in a tractor. Weight is your friend as long as you have enough tire to keep the ground pressure pounds per square inch within reason. I think you do. 

If you could mount two of these batteries behind the trans and two in the front one just in front of the motor and one over the front axle. WOW I think with the reduction you will have you should crawl over/through just about anything.

Somewhere else in the forum someone said that the motor is just part of the transmission. The power is in the batteries. It seems like there is lots of battery there.

The only negitive I can see is not knowing the age of the battery. If you buy, see if you can get them age matched. Remember 3 good batteries will still only perform as well as the one poor battery.

Look for some more users and see what they say. 
In the end, something like this goes on guts. In this case it will be your gut feeling after some of the battery experts chime in

My yellow Cub Cadet tractor has 48 volts 4 each 10 year old 42 amp hour AGM batteries from a UPS that are not deep cycle and I can run it for about 45 minutes with a heavy foot before I need a charge. The cub weighs 1200 to 1250 pounds with me on it and you can see in the YouTube videos the performance is spirited. I think with what you are building (with 4 of these batteries) you might see as much as 1500 pounds, I would call that reasonable. Performance with the smaller motor controller package won't be peppy but it will keep going and going and going

Your controller appears to be on the light duty side for a tractor, where you might need to pull a lot, of amps (350 is a bit of a weak number for 48 volts) for a long time. I think the controller will will go into thermal limit and fall down here. But it will get you started with something to make the tractor move though, until you find/build just what you need. Until then use a Big heat sink and lots of cooling air.

Last thought If you buy remember you only have 7 days warrenty on thes batteries. If you buy wait until you are in a position to test them.

As usuall here I am ramblin on. I have got to get myself more concise.


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## pm_dawn (Sep 14, 2009)

What does the '8 hour rate to 1.75VPC' on the label mean?

Well it means the amount of Ah you can draw in 8 hours before each cell in the battery is down to 1,75V which would mean total 10,5v for the 12v battery.

So it would be about a constant load of 12,5A for 8 hours (12,5A X 8 hours = 100 Ah) before the battery goes below 10,5V.


Regards
/Per


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## Woodsmith (Jun 5, 2008)

I was figuring on the batteries being cheaper then new but better then other used batteries.

The weight I don't mind as I was figuring on it as ballast. Also they could be used to get the MR2 running for testing.
It would be good to be able to have so much capacity for tools so that would be another benefit.

Testing would be awkward, I suppose I could rig enough up to test the tractor but as they are a 400 mile round trip away I was planning on picking up this weekend as I would be near the seller anyway. I could delay until the next opportunity.

If I buy them I will remember to check the dates with the seller to make sure I get a late and matching set.

Thanks for the explanation of the label, PM.


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## JRP3 (Mar 7, 2008)

The 48 volts on the controller is nominal rating, it should handle a fully charged pack. As has been mentioned with all the weight you have you might be pulling higher amps, depending on how you're geared and how you use it. Forced cooling and a heatsink might be necessary. I can say that my 400 amp Alltrax stays pretty cool but my motor can get warm when heavily loaded. I'm almost at stall speed at the top of my hill with a full trailer.


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## Woodsmith (Jun 5, 2008)

I am sort of hoping to pull some reasonably high amps to give me something to measure against. I will need to fuse it but at 350A I can only find fuses at 300A or 400A.

Still deciding on the best place to put the controller so that it is between the pack and the motor and can have a clean air supply for fan cooling if needed and still be weather proof.

I will need to be able to sort out suitable volt and amp meters and a tachometer to see what the set up is doing.

I won't get the Marathon batteries this weekend due to cashflow and I want to talk with the seller to find out about battery dates and stuff and be in a better position to test immediately to see if they are good.
I am going to borrow a set of Optima batteries from Simon Rafferty for the time being so I can set up.


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