1961 Volvo PV544 - Now EV544

[jclars]

I technically finished this in August this year 2024, and now have 350 successful miles on the build. It is a total EV conversion from scratch with a range of 110 miles. (I actually pushed it to 123 miles, but pooped out 200 feet from my driveway.)

If interested, I can create a build summary here, or provide a link to a rather prolonged and tedious build thread on another forum. Or just respond to questions if there are any.

John

[freebeard]

Basic specs? Battery type, etc.?

[Caddylackn]

Please provide a build summary and parts list.

Thanks!

[jclars]

Recognizing that this was my first Electro-Mod, understand that there was plenty of false starts and misdirection along the way. Without the help of online examples and forum participants, as well as excellent vendor tech assistance I would not have had the final success that I did!

That said, I also had to get rid of a hotrodder bias to show off the wrong stuff! Funny but true. I had that beaten into me the hard way by trying to show off the motor and components in a car that could barely fit in the battery packs, let alone the motor! It struck home when someone finally said "that motor is about as exciting to look at as the alternator on an ICE! Okay already!

So it started as a hot rodder might expect - What motor can provide better performance than the original ICE 70 HP? So this is what was selected after looking at available options:

Netgain's Hyper9HV with HyperDrive X144 contoller. 120 HP and 173 ft-lb torque. My hot rod heart skipped a beat!

I got the motor/controller on order and only then did I start to determine what batteries could fit. A mistake, but eventually helped me realize my hot rod bias ran deeper than I thought.

At the same time, I had learned that EV West had done a previous Volvo build and still had the design files for the bellhousing adapter, But they had no record of specific year and it was also a different model than what they had done! it was left to me to confirm a match to my particular car. Several CAD files later it was determined to be a match, as was the coupler they offered. I held my breath until they were on the bench with motor and original 4 speed transmission joined!

[jclars]

While waiting for the motor and adapter to arrive, I mocked up their relative position with a 9" dia plastic bucket down low in the engine bay. First appearances said I had a bunch of excess space for many battery cells.

I started with the use of US Postal Service flat rate boxes to approximate the size of Tesla 25V battery packs. Initially I had targeted 120 to 144 volt capacity while maintaining close to original weight distribution - an important consideration. That would mean 3-4 cells in front and two in back. That configuration would do the two things I didn't want - high center of gravity in front and chopping out the former gas tank hole in the trunk. I was also warned that the Tesla battery packs were trickier to adapt than the LFP cells.

So, I calculated out the number of CALB type cells needed to attain my voltage target to be 40 cells. I made blocks of wood to imitate the size of the LFP cells. No matter how I stacked them, I would be limited to maximum 24 in front and 16 in the rear = 128 volts. In front, I would likely have to chop some of the front grille area open, putting them further into the crash zone. In the rear, again I would have to enlarge the gas tank opening that I wanted to drop them into. But it was a better fit than Tesla packs and they would be new, unused and more stable. They also would not need water cooling.

When I started to build my EV, the salvage battery market was somewhat limited, while LFP cell options were becoming more numerous, less costly, and more dense - size was coming down and Amp hours were going up!

In the year of prep ahead of deciding on which way to go, the reality of my available space, including selected charging equipment, controller, and contactor/fuse boxes, became more evident as the size and locations became more fixed. I settled on 33 each EVE 280 amp hr LFP cells. These reduced numbers still calculated out to an approximate 100 mile range, and would fit available spaces, front and rear, without chopping into the car structure or body. While I had decided to wait until the last minute to get batteries to my shop, I had not waited to purchase and receive the charging equipment. This led to another problem...

[Logic]

It looks good so far!

Around here a Serial Hybrid makes sense: (preferably with a direct overdrive)
Power's more off than on in 'The New South Africa' so a Serial Hybrid means you can bring the 'lights' home with you.
I think a 20 kw efficient motorbike engine turning a good PM alternator is enough, if you have good regen:

MPPT-Supercaps-MPPT-battery:
Supercaps to absorb the high braking amps the battery cant take.
Then the 1st MPPT should get the slow speed/low rpm/too low voltage braking power into the caps or battery.

MPPT from the caps to the battery should get all the 'too low normally' voltage out of the caps and into the the long term storage battery.

Naturally, if the caps still have the voltage when you floor it at a green light etc, the (Max) power should/could come from them direct!
Errr.... OK I'll shut up now!

[jclars]

I like that logic, Logic!

I think my Volvo regen is limited to 124 volts, but always has excess with nowhere to put it. The trouble with my car is I'd rather just add more cells to raise that ceiling! My BMS tells me that even at full charge, if I stomp on it, I will have several cells in the red LVC zone.

I have been travelling for the holiday and not able to do the next build thread installment. Included a 700 mile road trip from Vegas, NV to Mesa, AZ and a loop to the Grand Canyon. All in a weezer of a rental economy car. Never again will I do an economy car in that sense. But now settled in one place with not much to do, so I should be back at it shortly.

John

[Piotrsko]

Only issue I see is that you cant buy reasonably the amount of supercaps a battery will substitute for. Haven't seen any capacitor rated in watt hours, yet. Yes they will suck up a pretty massive transient but that isn't measured in watt minutes the motor requires for more than a monentary part rotation.

[jclars]

Luckily, my source for the batteries was the same as for the charging system - Thunder Struck Motors. When I told them I had settled on 33 cells due to limited space, they said my Charger would then need to be downsized to the next level as well. I had only mounted it, and not used it, so they offered me a full refund in exchange.

As it turned out, I was getting a visit from a cousin from Denmark, and he was excited when I asked if he wanted to do a road trip down to pick up batteries in Santa Rosa. Of course we would take the long way there and back to make it worth his while (and mine).

So I made up a shopping list and boxed up the charger and hit the road. We took three days going down along the coast and then spent several worthwhile hours at the TSM shop. We loaded batteries, a new charger and many BMS components and viewed actual installations at their shop as they took time to explain everything.

We had wanted to drive back via San Francisco. My cousins dream. Definitely not mine! He had this vision of retracing Steve McQueen's street race from the movie Bullitt. Only in a Ford Explorer instead of a Mustang. A Ford Explorer full of LFP batteries no less.

That scenario was nixed when we saw on the news that the Asia Pacific conference was being held under tight security in SF. We jointly decided it probably wouldn't look good driving a car full of batteries even close to the event.

We headed across the Sonoma and Napa wine growing regions instead. Much better choice either way! We spent several more days driving home to make it a truly worthwhile road trip, paid for by the freight savings on picking up the batteries.

I tested all the cells when I got home, and while they tested out to within .02 volts of each other, TSM stressed the long discharge curve of the LFP battery and how I couldn't be sure where along that curve each battery might lay. They suggested I target 3.4v for each and start charging while I worked on other installations.

At least with the batteries in hand, I could use them to lay out terminal points and build battery boxes.

[jclars]

So I started building battery boxes with frames of 1" angle and panel sides of 1/8" aluminum plate.

Meanwhile, I got a low end 30 volt/10 amp power source. I hooked four cells up in series for each charge and set it to 3.4 v constant. Wow, seemed to take a long time. But I still had plenty to do construction the front and rear boxes.

But by the time I got to the second box, I had still only charged 8 cells. So, unwisely, I cranked up the voltage to 4.2 in order to raise the amperage. And walked away. Big mistake. When I returned to check on them, this group of four cells had topped out at 4.2v and automatically like it was supposed to do. But I had never intended it to actually go that far, hoping for just a bit of a boost to lessen the charging time. Well, I discharged them back to 3.4 and they seemed happy. No expanding like I had been warned. The next day the grace period was over and they grew at least 1/4" all around. They would no longer fit the boxes I had made. First case of an expensive boo-boo.

Plus, I couldn't plan on speeding up the charging/balancing process without a larger power source. More money, but at 3x the amperage output, things picked up considerably. Plus the new unit was much more reliable at shutting down the charge precisely at target voltage.

I ordered four new cells, at the time $125 each, plus $100 shipping. There went my road trip savings.