Hi everyone, first post here.
I'm interested in converting my JCB robot skid steer from diesel to electric. I admit I have little experience with ev conversions (save for a simple 48v dc brushless conversion on a small david bradley walking tractor I use here on the farm). I'm also far from an expert when it comes to hydraulics. I'd like to brainstorm my thoughts and see if anything is off base. I welcome any and all feedback.
The target is this - my 2001 JCB Robot 165
She has a reliable 44hp peugot diesel powerplant. I've had her in and out of the JCB dealer several times over the last year though. At this point I'm convinced she needs a head gasket (no coolant in the oil, but she blows coolant out of the overflow and starts getting cranky after 20 minutes of operating). The thermostat, water pump and radiator all checked out, so this is my next target. Diesel engines are a bit above my head, so I'm looking at a likely $1500-$2000 job to have a head gasket done. At that price, I'm really pushed toward swapping the whole power plant for an electric one which is what I really want. I don't want to underestimate the size of the project, but being a simple direct hydraulic drive for everything makes it seem simple (at least on paper).
As far as I can tell from the service manual, with standard flow hydraulics its rated for 14.5gpm with a relief pressure of 2650psi. Banging around some quick engineering calculations (Hydraulic Pump Calculations - Womack Machine Supply Company
) 14.5 gpm flow requires 27 mechanical hp at 2700 psi.
I'd like to stick with a 48v nominal system (I have other projects and a solar off grid system that run on 48v). This limits my choice of motor, but it seems like the curtis AC 9 would fit the ticket. It should deliver more than the required power at 48v (with 600A controller). The other obvious win is that it's available with an SAE A hydraulic pump mount, meaning I could bolt it directly to a hydraulic pump without any custom fabrication.
AC-9 motor kit w/ SAE A pump mount - AC-09 AC Induction Motor Drive Kit
Operating time is going to be limited by battery pack size. I'll be sacrificing run time for sure, but for my use on the farm, if I could get an hour of hard run time (an hour of operating without hearing protection and diesel fumes) that would be fantastic. I'm a fan of the bmw i3 modules (48v 60ah). I can get a salvaged battery pack from a local yard for a decent price. I'd be looking at 20kwh realistic for an 8 module pack.
BMW i3 60ah pack with 48v modules -
Are there any glaring holes in my plan? Anything I haven't considered? I haven't seen anyone do a project like this. Does anyone have any links resources for other direct hydraulic ev builds or conversions?