Toro Workman MDE conversion

Ribfeast

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Joined
Oct 7, 2018
Messages
51
Hi all,

I have a Toro Workman MDE, which is pretty much an electric golf cart with a tipper tray on the back, canopy etc.
It runs off eight 6V Trojan T105 batteries, two of which are pretty much stuffed. They are 225Ah capacity each from memory.

I'm debating popping in a set of 15 CALB CA180 lithium batteries as a replacement depending on cost, unless someone can recommend something cheaper? Would be nice to get some sort of 48V 200Ah Lithium setup affordably. I debated one of the Alibaba ones but reports from there seem mixed, and I think I'd have trouble getting them into to Australia.

The UTV came with a nice Delta-Q 650W 48V charger which should be suitable once I change the charge profile to lithium. We have a 13.8kW solar array to charge for free using the sun.

Apparently the controller on the cart is limited to 500A, which I think is within the limits of the CALB batteries (but pushing it).

We use this cart for feeding up the horses twice each day on a 40 acre property with a few hills.

Any advice appreciated :)

toro-workman-mde-dumpbed-sn-3524-a_1_orig.jpg


[moderator edit to add pic]
 
Hi Rib,

Sounds like a good plan. Trading 225Ah of lead-acid for ~200Ah of Lithium. I think you'll be amazed. Anyway, you should plan for a BMS of some sort. That will add cost and complexity. Also, you may need to send the charger in to have the algorithm changed. Member frodus can do that reasonably. Other than that, should be pretty easy swap.

Regards,

major
 
Used EV batteries are more available these days. Shipping them is difficult though. You might check your local auto dismantler to see if they have any from a wrecked car. Nissan Leafs are probably the most common. Chevy Volt batteries are probably better batteries.
 
Not many Leafs in Australia but this might be the go :) Or maybe a Holden Volt. Prius uses NiMH so no good.
Not seeing any Leaf, Volt, or Teslas on partslocator.com.au though. What are some other donor vehicles?
Aren't they just packs of 18650's though?

The Delta-Q charger has hundreds of profiles in it, I just need to run a button sequence on it to change to Lithium. You can also load new profiles via USB. It's only 650W so will take a while to charge, but should do the trick.
BMS is a good point! Will need one of those.
Do you reckon those batteries would handle the current load? Is there any affordable new options other than the CALB?
 
Ribfeast said:
...
Not seeing any Leaf, Volt, or Teslas on partslocator.com.au though. What are some other donor vehicles?
Aren't they just packs of 18650's though?
One of the more common in Au is the Mitsubishi IMev, and the Outlander PHEV. ( but still not many around !)
The Outlander has a 10 kWh pack, that is made up from multiple 40 Ah GS YUSA prismatic cells with screw terminals...easy to reconfigure for voltage and shape etc
 
Good tip, looks look neither of them on partslocator either though :( I'll look into the Yuasa cells. Prismatic seems to be the go.
Have just ordered a pair of HA02 battery balancers for the current lead acid set in the meantime.
 
Looks like the main fuse is 335A, and I *think* this is the motor in it:
http://www.evmotors.com.au/products/download/K91-4003.pdf
http://www.evmotors.com.au/products/k91.html
According to the spec sheet it is rated to 72V 300A.

So 335A peak draw is a bit easier to find batteries for than 500A :)
 
Do you know what controller it has? Many of them are programmable so you can set the current limit where you want.
 
Looks like a Sevcon? Toro Part# 110-2569
https://www.toro.com/parts/partdetails/?id=40577

And the motor is from Advanced Motors & Drives (Kinetek), part# 104-7335 or DV3-4005
 
The Sevcon is programmable but the programming interface is stupidly expensive. It appears to be a sep-ex brushed controller.

Normally you would only see the maximum amps when first starting out and at full throttle. Once you get some speed, the amps will drop. The battery limitation is really from heating so a short time at higher amps might not be a problem.
 
Maybe I should skip the lithium and look into an ultracapacitor? Should cover the surge current and regen braking nicely, and trickle it back to the batteries?
The Toro certainly goes fast enough for our needs, uphill not so much though.
 
Search "ultracapacitor" on these forums....then save yourself any more wasted time and effort !
Uphill performance is max power/current related, which could be any or all of the battery, controller, or motor limitations...hard to identify without some detailed measurements.
So no guarantee that changing the battery alone will cure that.
 
I think Lithium battery is the way to go. If you get a 200Ah battery, 500 amps is 2.5C. Any decent Lithium cells should handle that.

That Sevcon SepEx controller looks like ones I used a few years back, called Millipak, IIRC. I liked them. They pulled hard. Hills should not be trouble. If you are currently experiencing difficulty, it is likely a baddery.. bad battery or two.

Maybe Jones or Ripperton could assist locating a battery source. I forget Jones' username.

Regards,

major
 
Yeah I have two bad batteries in my bank of 8, so they sag after a short drive. Picking up some secondhand unused ones tomorrow night and will see if the performance improves, and re-evaluate a lithium purchase from there :)
Even a 100Ah or 150Ah bank would be OK as we usually charge once a day and wouldn't drive more than a km. Just have to be careful not to overcharge or keep them near 100% too long.
I'm guessing once cells, BMS, connectors etc are considered I'd be lucky to get any change out of $3000-5000AUD.

https://marinehowto.com/lifepo4-batteries-on-boats/
http://nordkyndesign.com/assembling-a-lithium-iron-phosphate-marine-house-bank/
http://nordkyndesign.com/practical-characteristics-of-lithium-iron-phosphate-battery-cells
http://nordkyndesign.com/lithium-battery-banks-fundamentals/#high-SOC-degradation
 
My experience with those Trojan 6v batteries is not positive.
We had a industrial floor scrubber with an 8 unit pack that was lightly used daily and recharged on the correct charger, and professionally maintained.
Pretty much every 12 months, that pack needed replacement due to dramatically reduced capacity !
Changing individual batteries proved only a short term fix , that just led to ever shorter run time.
Lead cells, have a short cycle life,..even so called deep cycle cells.
 
Yeah I'm not holding out hope, have bought a HA02 balancer for them that should arrive in a week, and am using a hopefully-decent charger (Delta-Q). Given it will spend most of its life on float and driven to no less than 70-80% SoC I'm hoping it will perform. Otherwise I'm researching the lithium option as an alternative :)
 
I have owned one of these units for about 10 years. Service wise I spend a fortune and the batteries are a pain so if you find a Lithium solution that works I will follow you!

I have another major issue and that is the 8 flash warning when I have been using it for about 60 to 90 mins continually. This is where the controller overheats apparently although I wonder if it could be the motor overheating and feeding that info back to the controller. The battery charge indicator usually suggests I have heaps of power left. If I turn it off for 5 to 10 minutes I can reuse for another 30 -45 mins without a problem.

Any suggestions/advice welcome for either concern
 
Yeah I hear ya, I've replaced 3 of the 8 batteries in the pack, and a 4th is about to die on me. Not sure if all the bumping around on the farm is splashing acid out, or something else. We have a few hills which flattens them quickly. I'd be interested to know how yours lasts, I'll get one evening horse feedup (10 buckets) and one morning feedup and then it's on charge all day. A feedup is around 15 minutes in total.
It has 2500hours on it so everything is pretty worn out, nearly at the point of selling it to get my money back ($9k).
Lithium battery packs (pre-built) from a mob in Australia here were about $6k, not including charger (current one not suitable either).

I might pull the brushes out and check the armature as it seems to run a ton better in reverse than forwards.

The HA02 balancers worked well but I suspect they hastened the demise of the 3rd battery (it dropped a cell) as they were all bubbling away 24/7. Also went through a ton more distilled water too (3-5 litres a week).

I haven't been checking for the flash warnings, but once I have lost 2 notches on the battery level the cart is essentially flat and only good on level ground after that.
 
Just found the old e-mail with the quote from EV Power, the 12V 100AH batteries are $850+GST each (need 4)

EVG12V100AH
$850 + GST
100 Ah
12.60 kg
273 x 128 x 245h
Complete with BMS modules

You would also require the BCU-PEV-16V battery control unit ($450 + GST) and one of their 48V chargers.

So $4235 inc GST, plus whatever the charger is worth.
I can get Trojan T105s for $259 AUD each, so a full set of 8 is $2072, half the price of lithium. Once you add in all the battery watering hassles, weight, acid corrosion and other drawbacks, lithium starts to look pretty attractive. In my situation it will all come down to the condition of the motor commutator bar, as brushes can be changed, commutator is much harder/ $$$$.
 
I wonder if 160 of these would be suitable?

https://www.ebay.com.au/itm/Lifepo4-Cells10AH-38120-Headway-Brand-Carton-of-24-cells-Aust-Stock/183413589284?hash=item2ab44d4524:g:iGgAAOSw5U9Zij7M:rk:2:pf:0#viTabs_0&autorefresh=true

3.2v 10Ah cells, $330 for a pack of 24, would need 160 of them, plus a charger and BMS...
 
The batteries do seem pretty expensive. A DIY pack made from EV car batteries would be a great option if they were available. Seems like the supply of those is pretty limited in your area. Bummer.

Personally, I would never go back to lead-acid. In the long run, the lithium batteries should be more cost-effective depending on how much you use it.
 
winemaker01 said:
I have owned one of these units for about 10 years. Service wise I spend a fortune and the batteries are a pain so if you find a Lithium solution that works I will follow you!

I have another major issue and that is the 8 flash warning when I have been using it for about 60 to 90 mins continually. This is where the controller overheats apparently although I wonder if it could be the motor overheating and feeding that info back to the controller. The battery charge indicator usually suggests I have heaps of power left. If I turn it off for 5 to 10 minutes I can reuse for another 30 -45 mins without a problem.

Any suggestions/advice welcome for either concern

Gotten sick of getting 15-20 mins runtime out of the lead acid pack. I've pulled the trigger on the order :) Details here:
https://forums.aeva.asn.au/viewtopic.php?f=18&t=5892&p=71728#p71728

Zeva BMS16v2
16x CALB CA100 LiFePO4 cells
Zeva screen
Reprogram Delta-Q charger to Lithium profile 162 or 233 (still confirming)
Contactor to cut pack off if exceeding parameters
Temp sensor
Cell interlinks
Assemble as per:
http://nordkyndesign.com/assembling-a-lithium-iron-phosphate-marine-house-bank/

Total roughly $3269.
I've purchased a regulated lab power supply from AliExpress - 60V 20A to do the initial charge.
 
Those should be a huge improvement over lead-acid. It is important to compress the cells like they show in the pictures. This is one of the more challenging parts of the conversion.
 
Yeah I have a stack of Formply sitting around, and bought some threaded rod on the weekend, so will assemble and balance charge as per below:

http://nordkyndesign.com/assembling-a-lithium-iron-phosphate-marine-house-bank/
 
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