# David Brown 880 Tractor Conversion



## Trickytrotter (11 mo ago)

I'm looking do a 40hp tractor conversion. I've managed to find, and have now bought, a David Brown 880 Selectamatic with a tired engine - rest of the tractor is mechanically sound (so I'm told), but it does need some TLC (definitely doesn't look anywhere near as good as the one in the photo below  ). So, here's my plan for the conversion so far:

If you look at the David Brown 880 picture below, it shows you the tractor and how the major engine and transmission components are layout.










And, the following gives an exploded view of those major components:

















My plan is to remove the engine - basically everything above the sump frame including the crankshaft. The sump frame will remain, as it provides the structure for the front frame (and front axles and wheels) to stay connected with the rest of the tractor. Although the sump frame may need some reinforcing, which I'll hopefully be able to do when mounting the electric motor and structures for holding batteries.

















The flywheel and double-clutch, one for PTO and one for transmission, will remain (NB. the orientation of the double-clutch diagram is 180deg out - i.e. the PTO friction plate end goes into the right-hand side of the flywheel in the left diagram). So, the electric motor will be attached to the flywheel - I will need to get a coupling manufactured to match how the crankshaft was bolted to the flywheel. 

However, as the engine normally runs from 700 to 2000rpm, I expect a reduction gearbox, or pulleys and belt, will need to be used between the electric motor and the flywheel. Plus the reduction box/pulleys-&-belt will also allow the motor to be mounted above the sump frame, as I don't expect there will be enough room down in the sump frame where the coupling will attach to the flywheel.

Anyway, that's my plan thus far (still waiting for the tractor to arrive). But, what do you think of my plan thus far?

Next step, researching electric motors (I'm think around 20kW?), controllers and batteries.


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## remy_martian (Feb 4, 2019)

Maybe cut the deck of the block down, pull pistons and rods out, put a plate on top of the new deck on which to put your batteries and drive it via a beefer front crank pulley?


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## Trickytrotter (11 mo ago)

Thanks @remy_martian. Great idea! Front crank pulley would then provide the gearing and the engine block would add more structural integrity for the sump frame. I like it!


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## remy_martian (Feb 4, 2019)

...and you don't have to futz with the dual clutch & flywheel setup


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## Trickytrotter (11 mo ago)

My donor tractor finally arrived last week. So, I started stripping the ICE over the weekend.

















On investigating how to remove the engine block (which means splitting the tractor between transmission and clutch housings) I've now realised that my Plan A (see posts above) to attach the motor via gearing to the flywheel (thus keeping the use of the double clutch for running transmission and PTO off the one electric motor) is flawed. The weight of the flywheel, currently supported by the ICE's crankshaft, would be quite complex to support without ICE, and then keeping it balanced and not putting strain on the shaft (I'd have to fabricate) and bearings supporting it. And the crankshaft can't be used, as it attaches to the block and not the sump frame and will need the oil pump running (essentially keeping most of the ICE components, which doesn't gel with me).










So, Plan B is to now do away with the flywheel and clutch and instead use two motors & controllers - one attached via gearing to the PTO shaft (the smaller shaft within the outer transmission shaft in the above photo) to drive PTO and rear hydraulics, and the second motor attached to the outer transmission shaft (the rear spline pictured above) to drive the tractor gearbox. Removes heaps of dead ICE weight from the tractor (more room for batteries ) and I believe this will be a lot more efficient too - don't need to run the PTO motor unless the PTO and/or rear hydraulics are needed. Could also use different gearing to suit each use too.

Right, this weekend's job - try and block & tackle out the great lump of an ICE


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## LrBen (Dec 30, 2017)

Great project! I have a Leyland 255 in the barn which I am planning to start converting later this year. Have a leaf motor ready for it.

I have also been pondering the clutch/no clutch issue in order to deal with the independent PTO and hydraulics. Very interested to see how you solve it on your project.


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## Trickytrotter (11 mo ago)

Thanks, LrBen.

I decided to go the no-clutch route. Quite glad I did now that I've stripped the ICE, clutch and flywheel out. The flywheel and clutch were quite a lot heavier than I thought and were basically supported by the ICE's crankshaft and the clutch's pressure plate splines mated to the PTO and transmission drive shafts. Anyway, here's progress to date:




Time to get rid of that fossil fuel burner...

To remove the engine first the tractor needs to be split at the clutch.




You can see the clutch pressure plate within the flywheel housing in the above photo.

Removed the clutch and flywheel (damn, those were heavy - glad I decided on Plan B). Then removing quite a few bolts (and one that took me ages to find 😀) and the oil pump, the engine could be hoisted out.




Clean up time and there we have our "blank canvas" - all the remaining bits of the tractor I will add the electrical bits to.




So, those shafts sticking out of the transmission are where I need to attach the reduction timing belt pulleys that will be belt driven by the electric motors. 





But, they'll need a bit of support.



The reduction timing belt pulleys will be splined and matched to the shafts like the old clutch plates shown below.




Only remaining issue I can see is that the flywheel housing won't allow me enough room to fit the motors, pulleys and belts inside it (as those shaft splines sit pretty much mid-way within the flywheel housing). So, I've now cut out the top of the flywheel housing.



This will allow the two electric motors to be mounted just above the flywheel housing (one probably facing backwards and one forward) with their belts running down through this cut-out to the pulleys on the transmission and PTO shafts.

I then bolted the front and rear back together (flywheel housing bolted back to the clutch housing). Might need to add some structural bracing to the cut flywheel housing and sump frame, but I think my 'blank canvas' is ready to go.




















Bunch of parts on order - pillow block bearings, timing pulleys and belts, motors and controllers, batteries (cheap deep cycle lead acid ones for testing), etc. So, no action for a little while, but plenty of tidying up work to do in the meantime...










Drained and replaced transmission & hydraulics oil and filters. Rebuilt the steering column and rack. Repaired rust in guards. A lick of paint and the rear of the tractor is now looking sweet!











Motors, controllers, batteries and a few other parts recently arrived (I'll provide details if these in another post soon). So, I could then mock up the layout:










My father-in-law is a design engineer, so he's now designed mounting brackets for the motors and confirmed timing belt pulley and belt sizes. So, with them on order it's more waiting now for a while  . But, it's all starting to come together...


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## electro wrks (Mar 5, 2012)

I've worked a lot with tractors this size and larger. Those motors look pretty small for the job. The overall power required shifts mostly to the implements when using tillers and large mowers, through the PTO, and to the drive wheels when plowing or pulling large loads. For this reason it might be better, power-wise, to use one larger, more powerful motor to power both the PTO and wheel drive. 

This tractor probably has a lever and dog clutch PTO engagement system. Without a clutch, you would have to stop the motor to engage the PTO, possibly also to disengage it. For safety reasons, you need to make sure the PTO can be quickly stopped. This goes for any set-up.


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## Trickytrotter (11 mo ago)

Thanks, electro wrks for your reply. I'm hoping I've done my sums right on the motors, at least for my needs anyway. We only have a small (12 acre), flat lifestyle block of land, so I don't need the tractor to do anything too meaty. Mainly towing a small car trailer around with hay on it and occasionally topping (small 1.5m slasher mower) some paddocks (takes about 20mins to top a paddock with my current Fergie 135 tractor).

I've also bought these cheap motors and controllers to start with, in case I have got it wrong. If I have to 'upgrade' to better motor(s) later, I'm ok with that. I've also gone with two different types of motors and controllers too, just to make the project even more interesting ;-). Fyi, the motors and controllers details are as follows:

For transmission: QS-Motor QS-180 motor with Far Driver ND72850 controller. Hope we get the 8kW rated (@4200rpm) & 15kW peak (6000rpm) and 18.2Nm rated & 65Nm peak (@1895rpm => and using 2.6:1 reduction this equates to 728 shaft rpm, which was pretty much the idle speed of the diesel engine).

For the PTO: a Golden Motor - HPM-10kW motor with VEC500 controller. Should give 10kW rated (@3700rpm) & 20kW peak (5000rpm) - 26Nm rated & 85Nm peak (again with 2.6:1 reduction it will increase the toque and power to the PTO shaft). The VEC500 has cruise control, which should be good for holding PTO speed.

Both motors running at peak power/torque is around 400A using 48V, so hopefully it's all enough. For comparison the DB880 ICE had peak 47Hp (35kW), when new, and 120 lb ft (160Nm) of torque, so with the 2.6:1 reduction and split load across the motors, I'm hoping we're within the realms of usability.

Yes, the PTO lever is at the rear, behind the seat. Will need to stop the motor to engage the PTO, but the PTO can be disengaged using the lever without stopping the motor. However, for both motors, I'm also mounting large 'emergency stop' buttons on the dashboard.

What do you reckon?


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## electro wrks (Mar 5, 2012)

Trickytrotter said:


> (again with 2.6:1 reduction it will increase the toque and power to the PTO shaft). The


The torque is increased proportional to the gear ratio, but the horsepower, or Watts in SI units, remains about the same. Horsepower is a measure of the ability to do work. That is to say to move a given weight a given distance over a given time. If you are satisfied with a tractor that can do less work, that's fine.

In practical applications it might mean you have to run a smaller diameter mower, a not as wide tiller, and to me the most frustrating part: crawling along at a slower speed on the public roads between fields.



Trickytrotter said:


> My father-in-law is a design engineer, so he's now designed mounting brackets for the motors and confirmed timing belt pulley and belt sizes.


I would recommend you have PTO slip clutches on any PTO driven implement that might jam and stop suddenly. Without a clutch, the teeth on the belt might be overloaded and stripped off. This just might be an application where a properly sized multiple V-belt drive system, that slips to accommodate a rare overload, is a better choice. On the overload subject, I don't know about you, but my first reaction when things go sideways on a tractor with a clutch(es) is to slam my left foot down on the clutch pedal. Maybe in addition to the kill buttons you could have some kill switches activated by the clutch pedal.

This looks like a fun project. As in: I wish I had the time and resources to finish the projects like this sitting in my boneyard! Keep up the good work and let us know how it goes.


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## Trickytrotter (11 mo ago)

Great advice! Thanks, for that. I'll keep posting as I progress to let everyone know how it goes.


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## darko (11 mo ago)

Following with great interest... I'm in the early stages of converting an Oliver 1800 tractor. Trying to come up with ideas for a clutch design (want to keep the live PTO), and single leaf motor.
I will be interested to see how things go for you with the geared belts - I'm thinking of 5-v-belt pulleys for the reason mentioned - in case things need to slip.


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## Trickytrotter (11 mo ago)

She's starting to come together nicely!

While waiting for the motor mounting brackets and timing belt pulleys to arrive I tackled the bonnet. Having all those electric bits I needed to make the bonnet more waterproof, including sealing over the fuel, water, exhaust and air-cleaner holes, and making a solid front grill (with mock mesh). And, of course, including new LED headlights 😃.


And, new decals and "EV" stickers.



As shown above, I repurposed the old tractor dashboard (which needed a sturdy mount, as it holds up the rear of the bonnet too) and installed the gauges (Cycle Analyst CA3 ones), switches and other controls I needed - one set each for the separate motors and controllers.

Yay! The motor mounting brackets have arrived, so now some real progress...


Motors mounted (still awaiting pulleys)

If anyone's interested, here's the CAD drawing for the mounting brackets:


After completing all the wiring and hooking up the batteries I gave the controllers and motors a test run. After trouble-shooting a few minor issues and getting a Hall Effect throttle for the transmission controller (couldn't get the Far Driver ND72850 to work very well with a potentiometer throttle) everything is working as expected.




Wiring is still a bit messy. I'll loom it all better once we've had some decent test runs and are happy that no changes are required.


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## Trickytrotter (11 mo ago)

And, here's a video of the me starting up and running the motors:


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## Trickytrotter (11 mo ago)

And here's my current wiring diagram...


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## Trickytrotter (11 mo ago)

*It's alive!*





Still some tuning of motor controller settings to do, but she's moving


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## Trickytrotter (11 mo ago)

Still a bunch more to do (motor controller tuning, lots of test runs to measure power loads, better batteries then procured and installed, chassis front-end refurbished, etc), but at least she's moving .


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## MarkDoronin (8 mo ago)

your work impressed me! You are a great fellow! I would like to know the price of the question - how much money did you spend, if it's not a secret and you can share it.

But anyway, you do an amazing job.


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## Trickytrotter (11 mo ago)

Thanks, Mark. Cost so far isn't a secret, but I haven't had a chance to add it all up yet. I'll try and collate the spend so far this weekend and let you know. Cheers.


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## MarkDoronin (8 mo ago)

I'm still waiting for expenses


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## Trickytrotter (11 mo ago)

Sorry. I've been away on a car rally. Here's the costs I have so far...


ItemCost (NZ$)NZ$ to US$Cost (US$)1967 David Brown 880 Donor Tractor2600.000.671742.00QS-Motor QS-180 Motor & ND72850 Controller2007.700.681360.00Cycle Analyst CA3 for PTO229.260.69157.111-3/4" Pillow Block Bearing82.000.6956.587/8" Pillow Block Bearing36.000.6924.84Golden Motor 10kW motor + VEC500 controller3160.350.662085.83Cycle Analyst CA3 for Transmission338.140.64215.13Various Switches & 12V Relays151.170.6496.752x 300A Shunts70.280.6344.47100Ohm 10W Precharge Resistors20.910.6212.8710k Potentiometer (x10 turn) for PTO control throttle11.220.6118.392x 600A Main Contactors228.990.61140.76Battery Cables (battery to contactor then to controller)291.080.65189.20T10 Timing Belt Pulleys (x4)477.710.64304.78T10 Timing Belt36.890.6222.89T10 Timing Belt48.220.6229.92Motor Brackets (custom design)1008.550.62625.30Hall Effect Foot Controller57.900.6235.90Hall Effect Angle Sensor for hand throttle51.030.6130.89T10 Idler Pulley20.430.5411.03Timing Belt Pulley Machining (splining)1101.700.57627.97Misc Nuts, Bolts, cables, cable ties, etc693.340.62 (avg)429.87Total12,722.878,262.48

NB. The Golden Motor items were purchased via local NZ dealer, whereas the QS-Motor stuff was bought direct from QS-Motor in China. So, would probably have been cheaper if I purchased the Golden Motor stuff direct from China too.

In addition to the above, for testing I've also spent NZ$1,033 (=US$642) on 4x Trojan T-1275 batteries (2nd hand), 4x 12V battery chargers, a 4-way battery balancer and some 13pin plugs & sockets (to make connecting balancer or chargers easily).

Next big costs will be the final batteries needed, battery management system and charger.

Although, I'm not overly happy with the QS-180 motor & ND72850 controller. If the PTO's Golden Motor motor & controller turns out to be better (I've yet to test that under expected loads, but initial light load tests look good), I may buy another set to replace the QS-Motor ones. So, fair to say all the above costs are not final yet 

Hope the above helps?


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## electro wrks (Mar 5, 2012)

Trickytrotter said:


> Although, I'm not overly happy with the QS-180 motor & ND72850 controller. If the PTO's Golden Motor motor & controller turns out to be better (I've yet to test that under expected loads, but initial light load tests look good), I may buy another set to replace the QS-Motor ones.


What's the problem with this motor/controller set-up?


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## Trickytrotter (11 mo ago)

electro wrks said:


> What's the problem with this motor/controller set-up?


The QS-180 motor & ND72850 controller doesn't seem to have much low rpm torque, which makes the tractor quite sluggish when pulling away from a standstill. It's ok once you get moving a bit, so need to use the gears (but I think it would struggle pulling out a small tree stump  ). I've played around with the controller programming settings, but none of the setting changes seem to make much difference (and there isn't a decent manual or information anywhere that explains what all the controller's settings do). The Golden Motor set-up seems to be better in this perspective, but I need to confirm with it under some higher loads. Plus, the QS-180 motor is quite noisy in comparison to the Golden Motor one too.


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## electro wrks (Mar 5, 2012)

Trickytrotter said:


> so need to use the gears


It sounds like you need a higher drive reduction ratio from the motor to the trans. input shaft, for the available power output of the motor. Roller chain drives are a lot cheaper and more convenient to use, initially, when trying to sort out the best ratio. Motor amp (or battery to controller amp) input figures would also be useful 

Also, the 40HP rating for the ICE in the tractor is a typically a very conservative, continuous rating. This is compared to the continuous ~10HP rating, with ~20HP peak for some seconds or a few minutes for the electric motor. Limited motor output may be a factor.


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## Trickytrotter (11 mo ago)

electro wrks said:


> It sounds like you need a higher drive reduction ratio from the motor to the trans. input shaft, for the available power output of the motor. Roller chain drives are a lot cheaper and more convenient to use, initially, when trying to sort out the best ratio.


Yes, good idea! Thanks for that.



electro wrks said:


> Motor amp (or battery to controller amp) input figures would also be useful


Well, that's the thing. The amp draw (battery to controller) is quite low (20 to 40A) during start-off, but then raises to 80 to 100A once it gets moving (approx 1000 motor rpm). Btw, I have the controller limited to max 120A draw due to test batteries I'm using. As I say, I've been trying to tweak settings in the controller, but nothing has made much of a difference yet.



electro wrks said:


> Also, the 40HP rating for the ICE in the tractor is a typically a very conservative, continuous rating. This is compared to the continuous ~10HP rating, with ~20HP peak for some seconds or a few minutes for the electric motor. Limited motor output may be a factor.


Yep, motor may be a tad small (as you mentioned in an earlier post  ). More testing will confirm. Could perhaps double the motors up, but will likely get something bigger.


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## electro wrks (Mar 5, 2012)

Trickytrotter said:


> Well, that's the thing. The amp draw (battery to controller) is quite low (20 to 40A) during start-off, but then raises to 80 to 100A once it gets moving (approx 1000 motor rpm). Btw, I have the controller limited to max 120A draw due to test batteries I'm using. As I say, I've been trying to tweak settings in the controller, but nothing has made much of a difference yet.


You may be dropping down to the low voltage cut-off of the controller. Try some bigger batteries.


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## Trickytrotter (11 mo ago)

electro wrks said:


> You may be dropping down to the low voltage cut-off of the controller. Try some bigger batteries.


I'll check again, but I never noticed a big voltage drop on the Cycle Analyst. Plus, I think the controller would stop the motor on low voltage, rather than reduce the amps, wouldn't it?


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## ratchet6900 (10 mo ago)

Hey, just read up on your most interesting project - especially interesting to myself as I am contemplating a Yanmar 15HP diesel tractor conversion. As it so happens, I am looking at the Golden Motor 10 KW for the main drive (although it's a little light on torque compared to the diesel). As for hydraulics, my pump is driven directly by the engine so I would need a separate electric hydraulic pump (if I can find one that runs on 48V). I'm thinking of going with lead-acid as well as lithium can be a pain to deal with in cold weather and I don't need especially long run times.

I'm wondering though if the clutch should be left in place as the tractor's transmission is non-synchro and it is necessary sometimes to double clutch when switching gears (I'm not sure how that would work with a no clutch/elec motor setup).

I'm a bit surprised your QS motor has low starting torque - sounds like it may be a controller issue and, rather than replace the motor, maybe try a different controller brand. I mention that as I have a small electric quad on which I replaced the stock controller with a (programmable) Kelly unit and am very pleased with the results (excellent low range torque and smooth speed control).

Looking forward to hearing about further progress with your conversion!


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## ratchet6900 (10 mo ago)

PS, have noticed the QS-180 motor is rated at 72 to 96V. Could this be an issue, particularly low torque, when operating with a 48V battery?


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## remy_martian (Feb 4, 2019)

You've set your battery voltage, vs choosing a motor and battery voltage that work together. 

Enjoy the pain from silly constraints.


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## Trickytrotter (11 mo ago)

Thanks, Guys. Yes, even though the QS-Motor's sales guy said the ND72850 and QS-180 would work ok at 48V, I do think it's more suited for 72V plus. Through tweaking controller settings I have managed to get it better than it was, but as the Golden Motor is working so well on the PTO (30A draw while running my 1.5m rotary slasher and hydraulics), my next step is to try the Golden Motor running the drive transmission and test that.

Btw, I've now completed a 10min mowing test run with the tractor and rotary slasher - results were:

1. PTO motor start and PTO shaft to 700RPM (2.6:1 so motor = 1820RPM), raise mower & lock* = 0.17Ah
2. PTO motor stop, Drive motor start and travel to paddock (approx 250m - High 3rd gear = 8km/h at avg 60A draw) = 1.90Ah
3. Start PTO motor, lower mower, start mower (PTO shaft to 1000RPM) then mow weeds in paddock for 4mins = 5.33Ahr (PTO avg 30A and Drive avg 50A in high 2nd gear, using eyeball on gauges)
4. Stop mower, raise & lock*, stop PTO motor aand then drive to shed and park = 2.10Ahr
Total = 9.50Ahr and approx 10mins running all up. (150Ahr Lead Acid batteries were probably getting near the max usable depth of discharge after that run).
*NB. The David Brown 880 has a lever to lock the hydraulic arms in the up position, so saves having to run the PTO motor to run the hydraulics while traveling to & from the paddock.

@ratchet6900 I am able to change gears, with a wee bit of crunching, by matching revs on up-change and blipping throttle on down-change - just like a crash gearbox in an old truck. Getting smoother doing it the more I'm getting used to it 

My lead acid batteries (Trojan T-1275s) are just wet ones. If you use AGM or lead-carbon ones then you should get better capacity and depth of discharge, but I think I'll eventually go LiFePO4.

She's a fun project though


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## ratchet6900 (10 mo ago)

Thank you for the update. I will be very interested to see how things perform with the Golden connect to the transmission (if it will perform well with your larger tractor, it should be extra fine for mine). Did you BTW see any motor heating problems with the Golden running the mower?

Not clear on your battery drawdown - the mowing session used 9.5 Ah but the 150 Ah batteries were almost depleted? Were batteries low when you started?


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## Trickytrotter (11 mo ago)

No heating issues - temps hardly moved (it was a 17degC day).

Not so much the draw-down on the battery (so my "depth of discharge" comment was probably a bit misleading, sorry), but rather the voltage dropping with the continuous 80A to 100A draw (got down to around 46V). Once I stopped the mower and was driving back to the shed the voltage rose a bit again (back to around 47V). So, I don't think my current batteries would do much more at the high load.


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## electro wrks (Mar 5, 2012)

Trickytrotter said:


> 1. PTO motor start and PTO shaft to 700RPM (2.6:1 so motor = 1820RPM), raise mower & lock* = 0.17Ah
> 2. PTO motor stop, Drive motor start and travel to paddock (approx 250m - High 3rd gear = 8km/h at avg 60A draw) = 1.90Ah
> 3. Start PTO motor, lower mower, start mower (PTO shaft to 1000RPM) then mow weeds in paddock for 4mins = 5.33Ahr (PTO avg 30A and Drive avg 50A in high 2nd gear, using eyeball on gauges)
> 4. Stop mower, raise & lock*, stop PTO motor aand then drive to shed and park = 2.10Ahr
> Total = 9.50Ahr and approx 10mins running all up. (150Ahr Lead Acid batteries were probably getting near the max usable depth of discharge after that run).


Are you sure your Amp and Amp-hour figures aren't off by a factor of 10? Something doesn't multiply out and add up with the size of the equipment used and the amount of power and energy used. 30A X 48V=1440W, about 2 HP. In my experence, that would barely be enough power to rotate a 1.5m(~60") rotary mower(if we are referring to the same type of mower), let alone mow with it.


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## ratchet6900 (10 mo ago)

What about switching the transmission to reverse and vice versa (that's where I have to frequently double clutch)? I suppose though the best method would be to simply reverse the motor.

That much voltage drop for the draw you calculate seems quite excessive. Weak battery cell(s)? Might be an idea to measure individual battery voltages.


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## remy_martian (Feb 4, 2019)

A tractor is not meant to be shifted on the fly...


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## ratchet6900 (10 mo ago)

remy_martian said:


> A tractor is not meant to be shifted on the fly...


Not moving when shifting forward/reverse. Still need to double clutch frequently.


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## Trickytrotter (11 mo ago)

Thanks everyone.

Let me double-check my Cycle Analyst settings - perhaps I have added the wrong shunt values.
Yes, my batteries are probably a bit suspect.

Not sure what you mean about needing to double-clutch when shifting from a forward gear to reverse, sorry. I just need to stop the tractor moving, drop the motor to zero RPM and then I can change gear from forward to reverse or vice versa without any issues.

Oops, didn't know about not shifting tractors on the fly. I do it on my Fergie 135 all the time - especially 2nd to 3rd, but also down shifting when I need to slow for bumps & corners. Maybe I shouldn't be...


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## ratchet6900 (10 mo ago)

When shifting from forward to reverse (with tractor stopped), it doesn't grind but simply, about 1/2 the time, will not go into gear (the gearshift lever will move only a short distance. Double clutching almost always works the first time.

I suppose one could best & easiest just flip the motor forward/reverse switch - and gives the added benefit of having more reverse gears available (the YM155 has only two reverse gears, one usually too slow and the other often too high). Would be OK I guess as long as the PTO wasn't being used...


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## remy_martian (Feb 4, 2019)

^^ I think it's a reason why Ferguson came up with the hydrostatic up/downshift (I forget the name...our 165 had it, my 65 and 135 do not).


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## ratchet6900 (10 mo ago)

Nothing wrong I can see with shifting a non-synchro on the fly as long as w/o gear grinding or popping the clutch.


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## remy_martian (Feb 4, 2019)

No, there's nothing wrong. It's just a very unusual way to operate a farm tractor.


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## Trickytrotter (11 mo ago)

Ok, so I scrounged up a couple more batteries and hooked up the QS-180 main drive motor to 72V (increased from 48V) and that has made a definite improvement. Tractor is quite lively now and from the couple of short tests I've made the motor doesn't seem to be straining as much as it was at low RPM and it's definitely got more high-RPM speed in top gear. One battery is quite tired though, so I'll try and get a replacement, do some more testing and then post the measured results for you soon. Looks like I'll need to buy a 72V VEC500 controller for the PTO motor now though


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## ratchet6900 (10 mo ago)

Sounds like a nice improvement. Do you think more could be realized, apart from replacing the weak battery, by upgrading to batteries with higher current capacity i.e do the Surrettes have enough to drive the motors to full output?

I ask in part because I've found that a battery bank, either LA or Lithium, capable of fitting in my possible Yanmar conversion can only provide about 100A continuous which is insufficient to drive the motor that would be required.to give full continuous output.


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## Trickytrotter (11 mo ago)

Sorry, I'm only using the 6 LA batteries (4x Trojan T-1275 and 2x Century 120ah AGM - all secondhand that I got cheaply) for initial testing. Once I'm happy with the motor and controller set-ups, I'll then use the test data to properly size the battery requirements. I'll then see what suitable battery, BMS and charging options are available here in New Zealand.

But, yes, I have each controller set to limit the max line current to 120A at present. So, with a battery set-up that can handle a larger peak power draw then it should perform better still.


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## ratchet6900 (10 mo ago)

OK, (I don't know where the Surrettes came from.  ).

Are you thinking LAs or maybe Lithium for future?


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## Trickytrotter (11 mo ago)

ratchet6900 said:


> Are you thinking LAs or maybe Lithium for future?


I haven't really researched that area yet. I believe the costs are high for some options, so that will be a factor!


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## Trickytrotter (11 mo ago)

Quick update on progress. Turns out the 48V VEC500 controller and motor (Golden Motor 10kW) I have can run at 72V. Just needed to program the controller for 72V. So, the whole project is now running at 72V and everything is working well.

I now need to find some time (and clear weather) to do some some decent test runs, including mowing grass, towing a laden trailer, etc, so that I can better measure the power requirements for sizing the final battery configuration (and type). Will post the results at some stage.


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## laf3142 (9 d ago)

Hey, I was wonder about your project yesterday so thanks for the update. Looking forward to test results.


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