Electric conversion of a Kubota B26 / Similar

[Bob Rooks]

Just throwing my two cents at you - seems you'll likely ignore it anyway.

A flywheel stores kinetic energy, and would be a good idea behind an electric motor to help in absorbing amperage spikes when operating the hydraulics and hydrostatic drive, particularly simultaneously. The main issue I see is the high amperage inrush needed to get the flywheel in motion from a static state. I believe this issue can be solved by eliminating the flywheel altogether and direct couple the electric motor to the hydraulic pump, and incorporate an adequately sized accumulator. The pump would only run when the pressure fell to a predetermined point.

 

[galstaf]

Just throwing my two cents at you - seems you'll likely ignore it anyway.

Oh contraire, everything is on the table right now.

Thanks for the input!

 

[/pine]

How long do you anticipate the charge will last on your battery pack ?...after what type of work ?

 

[Phil Timmons]

I have a shop manual of course. I realize it is not a simple project but was looking for leads on anyone that had done something similar that I could potentially collaborate with.

So how is this going so far? What are you finding and what are you needing?

Can help you on the design and details, if you like.

Sounds like you may do some stationary work? e.g., Backhoe, etc. If so, I would encourage you to consider a cord connection option, as well. So you move around on a smaller battery set up, and when you get in place, you can "plug in" and use line power for some hours without concern for battery life. You can even charge up the batteries while working. That is how we the BIG 1000HP + rigs.

 

[greenerdreams]

the main thing i am thinking is the batteries will be expensive and short lasting. Teslas(as well as most other all electric vehicles)have huge batteries that weigh a lot and take up a lot of space, this is in a car that is traveling pretty efficiently and only when needed. Since the tractor is hauling, lifting, driving over soft terrain etc. it is very inefficient and still needs a constant hydraulic supply as well unless you want the usefulness to be very low if you wait for hydraulics every time you move the bucket, it will use power very quickly. Even the electric mowers available don't last long and they are asking much less from a machine.

 

[Frogmore]

An HST tractor is a poor starting point choice for an electric conversion. But, let's just start with how much energy storage you need for all day usage. Let's use 10 hours for the day (to give you some reserve and room for degradation). At an average of 5HP (so 5:1 peak to average) that is about 35-40KWH. That is likely more than you will want to buy.

 

[Bob Rooks]

In my industry there are many success stories using electricity. On one of the vessels I worked on for years had a "power Island" propulsion system which consisted of a 4,160 volt buss and four 5,000 HP AC cycloconverter drive motors, and hotel load, all driven by four 3 mW diesel generators. The vessel is currently being reconfigured to full electric operation. Three of the diesel generators are being removed and replaced with battery banks. It's my understanding that the existing drive motors will be used. They are already using all electric tugboats. You can do this but I think the batteries will be the real challenge. Maybe you can find a used Prius battery to experiment with.

 

[Phil Timmons]

the main thing i am thinking is the batteries will be expensive and short lasting. Teslas(as well as most other all electric vehicles)have huge batteries that weigh a lot and take up a lot of space, this is in a car that is traveling pretty efficiently and only when needed. Since the tractor is hauling, lifting, driving over soft terrain etc. it is very inefficient and still needs a constant hydraulic supply as well unless you want the usefulness to be very low if you wait for hydraulics every time you move the bucket, it will use power very quickly. Even the electric mowers available don't last long and they are asking much less from a machine.

True. Part of why I am encouraging galstaf to consider a cord / cable option for this. Will also save a ton of money on the battery. Can build it with a little battery, and then add if he discovers he needs more. Covered part of this on this thread >>> Cord Management on Grid-Connected Electric Tractors and Mobile Equipment

 

[4570Man]

Do yourself a big favor and just fix the diesel. An electric tractor needs to be built electric from the ground up and even then the run times aren’t impressive. Trying to run all the hydraulics with battery is too much loss.

 

[shooterdon]

Being on the leading edge is always an expensive venture...but someone needs to do it or we would still be using oxen and horses.

Take a realistic inventory of you level of expertise, time to learn, time to get the work done and financial situation. On the money side, take your "reasonable" estimate and add a minimum of 100%. Time estimates are not as painful...if it takes you a year instead of 6 months it is not a big deal.

Good luck!