Batteries - EV Conversion

That's merely a case of perfection being the enemy of good enough. Methane is the best bridge fuel we have access to in quantities and at a cost that isn't hugely disruptive.

bob prohaska

----------------------------------------- And yet it is inferior to electricity as a heating source?

Electricity isn't a source, it's a transmission medium, same as hydrogen.

Perhaps I'm missing your point, if so please elaborate.

bob prohaska

Electricity isn't a source, it's a transmission medium, same as hydrogen.

Perhaps I'm missing your point, if so please elaborate.

bob prohaska

--------------------------------

Not sure what you're driving at. The COP of a heat pump in a warm climate (like Britain) can overcome the losses inherent in generation. Not always, and certainly not everywhere.

Use of a bottoming cycle gas turbine/steam generating plant helps a lot. bob prohaska

Not sure what you're driving at. The COP of a heat pump in a warm climate (like Britain) can overcome the losses inherent in generation. Not always, and certainly not everywhere.

Use of a bottoming cycle gas turbine/steam generating plant helps a lot.

bob prohaska

-------------------------------------

I don't have a simple answer, my point is that there are multiple tradeoffs to consider and try to balance, which appears to be beyond the mental capacity of the greenies who demand action they can understand.

Got an old electric fork lift flying around??? far from state of the art, but it will make a dandy parts chaser. Nickel iron or lead acid battery - heavy for the range, but useable. The old EV1 controller was pretty reliable and tuneable. And old electric fork lifts are DIRT CHEAP today On my old Fiat back in the late seventies I'd have KILLED for that obsolete teck. I used contactors and resistors - anf gold cart batteries and the generator from an old bomber as the motor. Made my own adapter plate to the originalstandard trans and ran it without a clutch.

The 24 volt aircraft generator run at 48 volts thought the 4 speed would burn the tires off the Fiat in 1st and occaisionally second - but it was NOT fast/quick. with 8 GC2H batteries I got 30 miles at 50MPH and 30 at 50 on an overnight charge that in 1978 cost me all of $0.25 here in Ontario - - Used the charger from a Sebring UrbaCar

Get a late model wreck and do a transplant - -r what all the hot-rof guys are foing now - drop an LS in it. Lots of them available with decent low mileage from trashed GM vehicles and parts are EVERYWHERE - including all the bits you need to do the swap.

Actrually no horsepower is NOT horsepower -

A400 HP cummins will out pull your 400HP Chevy LS - any day of the week. The torque curve is what you need to look at. How often will you be running full throttle at 5900 RPM under load to produce the 6.2L LS3's rated 430HP???? Even at Peak torque RPM of 4600 RPM (425 ft lbs) you are only baking

Electric motors are TOTALLY different - particularly dumb as a rock series wound traction motors that will take all the amps you can give them at zero RPM and produce INSANE torque - and will draw virtually NO amps, and produce virtually NO torque at INSANE RPMs

The generator used as a motor in my FIAT produced about 18HP 36 would have been quite adequate. 100hp in a ram 1500 would make a nice town truck with gears, and would not be TERRIBLY painful for short highway jaunts.

Find a copy of Paul R Shipps'"WV Engineering Guidebook" for all the tables to determine the horsepower/performance requirements for ANY conversion. This was the "bible" for EV conversions in the 1980s. (3e vehicles, San Diego Ca)

Lots od "standalone" computer options for the automatic - that's not an issue - but the automatic costs you a lot of efficiency in an EV where idling in gear is not required, and nor is a torque converter (or clutch) for pulling away. Stick a manual tranny behind it.

EV is on the back burner for now. I've been trying to clear out my folks commercial property for sale or lease, and that truck does have to go, but there is a fellow nearby who rolled an almost identical truck who might benefit from this one. I'm not against doing it anyway, but if I can sell it to somebody local to the property that saves me a half day (half days are really whole days) hauling it to my place or to the salvage yard.

In the mean time I hauled another truck away from the property. A 2000 Ford Ranger with (I was told) a good 4.0L engine and a bad transmission, except the transmission is completely missing. I saw some connectors hanging down, and looked underneath. Yep the tranny is gone. Atleast the drive line was in the bed when I opened the camper doors to take a look. Also missing is the exhaust section with the catalytic converter, which is, amazingly not that expensive when looked up on Rock Auto. I guess I'll look around to see if I can find the transmission, but I've been through the property before.

Next time I run out that way I plan to change all the locks on the gates, doors, shop, etc on the property. I've got an insane bucket of keys, and I am trying to eliminate most of them. If I can put that property on just one or two keys it won't make a dent, but it will help. I need to replace the jam on one door, but it leads into a single room that has a locked door between it and the main building. Well replace, all the locks, but one on the front commercial glass door. Its an oddball. I hope I can find the key for it, otherwise I'm going to have to spend an afternoon watching videos from "The Lock Picking Lawyer. Like many commercial locks it generally can't be removed from either side when the door is closed.

Next vehicle to haul is probably the 42 Willys. Its been sitting about

I did turn one thing back into cash. The Ranger had a contractor work cap on it that I originally used on my S10 pickup when I was using it as my personal service vehicle. When I sold the S10 I kept the cap and gave it to my dad. That old steel Gemtop shell still holds some value over the aluminum most work caps are today. I sold it after many years of use for nearly what I paid for it back in 2002. Of course it would be three to four times that much to replace it new today.

The Ranger is in decent shape, but the driver's window was converted from electric to manual, or manual to electric. The passenger side has buttons, but no crank, but a cover for a crank hole... The driver's side has both buttons and crank. The paint is "crunchy" like a bubbling clear coat or something, and there is a bullet hole in the passenger side rear door. I may wind up hauling that one to the junk yard. I don't see it being worth making drive-able again for myself, and they don't tend to sell for enough to be worth making it into a runner to sell. Maybe an alternative for an EV conversion. LOL. Lighter, but then not as much suspension to handle batteries. Nah, probably not. On a positive note. No body cancer.

---------------------------- LiFePO4 has a higher internal resistance and lower maximum current capacity than Li-ion or lead batteries.

The internal BMS, the protection circuit, limits the current from one battery and also the total current and voltage from a pack of several batteries in series and parallel.

For LiFePO4 the current limit is typically the Amp-hour rating or a small multiple of it, while Li-ion cells and batteries are available with maximum current ratings of 50 or more times the Amp-hour capacity.

For LiFePO4 the current limit is typically the Amp-hour rating or a small multiple of it, ...

--------------------------- Which means that a 12V, 100Ah LiFePO4 could ideally power a 1.6 HP motor for an hour. 16 of them in the BMS maximum 4S4P configuration equals 25HP. I had such an engine in a Beetle, whose 0-60 time was 15 minutes while the tranny oil warmed up.

That was a good excuse to avoid the Autobahn and instead wander through picturesque little villages on service calls. At the time the Autobahn was a squareish loop around the edges of Bavaria and cutting across diagonally was nearly as quick, plus a Jeep or Army truck wasn't much faster and I couldn't leave them parked outside a Gasthaus overnight.

From what I have found the only "economical" way to even make good use of a mid voltage motor like the Hyper 9 is to buy used commercial EV cells. If I ran with something like a 48 volt forklift battery as Clare Snyder suggest I could run multiple LiFePos in parallel, but for higher voltages I'm stuck with used commercial Lithium Ion EV cells. Well, new cells/modules are available, but they price puts it back in new car range.

MOTOR, not battery,

From what I have found the only "economical" way to even make good use of a mid voltage motor like the Hyper 9 is to buy used commercial EV cells. If I ran with something like a 48 volt forklift battery as Clare Snyder suggest I could run multiple LiFePos in parallel, but for higher voltages I'm stuck with used commercial Lithium Ion EV cells. Well, new cells/modules are available, but they price puts it back in new car range.

Bob La Londe

------------------------------------

I think (risky) the reason for the limit to how many you can parallel is the overheating (fire?) risk if the control of one BMS fails and it passes the entire load current, IOW the design margin. Likewise the series limit is the voltage rating of the MOSFETs if one BMS has to sustain the whole pack charging voltage.

If that's correct you might at least need a fuse or DC-rated circuit breaker for each set of 4 in parallel. The explanation I read wasn't written by/for engineers.

The prototype EV batch I helped build had 300V Li-ion batteries and I was the tech who had to diagnose (while hot) and fix their problems. Like my APC UPS there was a high current jumper plug to pull out and open the battery circuit to work on it. I am NOT qualified to give detailed design advice.

The special instruments I bought for high voltage and current are a 1KV Megger to check insulation, a micro-Ohmmeter for cable and contact resistance and a thermal imager to show hot spots. The micro-Ohmmeter found a batch of Chinese cable apparently made from scrap instead of pure metal, with much higher than expected resistance.

The alternative is passing 1 Amp through the Device Under Test and measuring the voltage drop in milliVolts, which equals milliOhms.

MOTOR, not battery,

---------------------

No problem, I'm used to decoding challengingly translated foreign tech, sometimes Chinese or Hindi to British to American. I was on the mumbling and bumbling side when trying to explain automotive and electrical problems in German.

I was thinking something as simple as 4-48V prebuilt modules/batteries in parallel each with its own BMS. Something like the LiTimes 48V batteries. They state its okay to run up to 4 in parallel. A fuse to each battery might cure the shutdown/overload, but those units have their own peak overload internally in the BMS. Thermal shut down as well. Its one of the reasons I was looking at the LifePo batteries available off the shelf. Lots of them with thermal shut down and peak load shutdown. Just check the reviews to see which ones actually work. LOL. Prouse does a good job of reviewing batteries on his YouTube channel.

The Hyper9 which is really at the bottom of the EV motors I'd consider really likes to have available 100+ volts (144 if I recall). Not an options with the prebuilt LiFePos. None of them seem to be rated to run enough in series to get that. The bigger motors all seem to be 400V+.

I was thinking something as simple as 4-48V prebuilt modules/batteries in parallel each with its own BMS. Something like the LiTimes 48V batteries. They state its okay to run up to 4 in parallel. A fuse to each battery might cure the shutdown/overload, but those units have their own peak overload internally in the BMS. Thermal shut down as well. Its one of the reasons I was looking at the LifePo batteries available off the shelf. Lots of them with thermal shut down and peak load shutdown. Just check the reviews to see which ones actually work. LOL. Prouse does a good job of reviewing batteries on his YouTube channel.

The Hyper9 which is really at the bottom of the EV motors I'd consider really likes to have available 100+ volts (144 if I recall). Not an options with the prebuilt LiFePos. None of them seem to be rated to run enough in series to get that. The bigger motors all seem to be 400V+.

Bob La Londe

------------------------

I've done enough with EVs to know I'm not qualified to design one fit to mix with traffic on public roads, or to properly design the power steering and power antilock brake accessories. I had trouble with the hydraulic lift for my bucket loader. The electric motorcycle for (???) was at my limit. I can only test and maybe modify/repair those things under an engineer's supervision. Sorry.

The mathematics of the Segway brushless motor drive is worthy of NASA, I know because I've been exposed to both and studied it in night school.