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Re: iMiEV as workhorse

Posted: Fri May 24, 2019 8:28 am
by WReed82
Hi Bradley,

The DC~DC converter can take power out of the big battery at a rate of about 80 amps x 12 volts = 960 watts.
Your 8A, 120V saw pulls 960 watts, so on paper a good match.
Except the 12VDC > 120VAC inverter power conversion losses take some of that power, and
the I-MiEV DC~DC converter isn't that stout, so going easy on it will likely give it a longer life.

I suggest reading this thread:
viewtopic.php?f=9&t=4251&hilit=inverter+weogo

A battery powered chainsaw could work well.
Here's one review:
https://www.popularmechanics.com/home/t ... d-you-buy/

Thanks and good health, Weogo

Re: iMiEV as workhorse

Posted: Fri May 24, 2019 11:31 am
by jray3
Bradley, I'd say go for it with your inverter and chainsaw. I've used MR BEAN as a mobile jumpbox for my big diesel truck many times, boosting dead lead batteries for long enough to melt the bad crimps on jumper cables, and then continuing with better cables for 30 minutes or so. I've also left the headlights on and radio blasting for hours at a jobsite. Did this contribute to the OBC failure at 80k miles? Perhaps, but if so, only through cumulative wear. A buddy who's a little old man in a 35 mph district, does nothing but normal driving and only racked up 40k miles in 7 years had his charger/DCDC fail this winter. (Though he had yanked the plug before disconnecting the handle a number of times.) We both had the same failure mode; cracked blue capacitors.

Re: iMiEV as workhorse

Posted: Sat May 25, 2019 9:20 am
by JoeS
Whoa! Once again, need to do the math: in crude terms, 960W/12A = 80A! Accounting for inverter inefficiencies, you could easily be attempting to draw 100A at 12v to power that small "8A" chainsaw.

To safely handle 100A, formally you need something like #2AWG wire, depending on insulation, and serious mechanical attachments to both the battery and inverter. For these short lengths and intermittent duty I think you could get away with #4AWG or #6AWG.

Why would we want to stress our dc-dc converter?

Quoting from the above referenced link, I had written:

"So, back on topic and to answer the original question regarding our i-MiEV as an energy source: even though it could provide much more power, I personally wouldn't want to draw more than about 100W out of an inverter hooked up to our i-MiEV 12v battery (the car in READY), especially nowadays as our OBC/dc-dc is proving to be iffy."

For the last couple of years I've been successfully using corded electric chain saws doing some serious work around my property (remember, I'm in the hills in a fire danger zone and must keep things clear). What I have is a 48v "power plant" mounted on a little red wagon consisting of Headway 12Ah LiFePO4 cells in two nicely-packaged 4P8S configuration modules in series and an inexpensive 2500W 48vdc --> 120vac square-wave inverter. Even with this setup, the inverter occasionally cuts out under a seriously-heavy load.

If you want to use 12v as a source fed by the i-MiEV, I would use a separate huge 12v battery and feed it from the i-MiEV through a small resistor to limit the instantaneous current being sucked out of the car, and don't forget the car needs to be in READY.

That said, knowing now what we know about the fragility of our OBC/dc-dc, I wouldn't mess with the i-MiEV's 12v battery any more.

Suggest we continue this discussion on this thread:

http://myimiev.com/forum/viewtopic.php?f=9&t=4251

Re: iMiEV as workhorse

Posted: Thu May 30, 2019 5:06 am
by bradleydavidgood777
I have avoided doing the math again!

Spotty tornado thunderstorms brought down 10 huge trees on the back road in my 2 mile wood scavenging loop near my house. I got this stuff in two and a half loads. These 4 foot sections are normally what they leave on the side of the road and fit nicely into the I-M if you have 2 people.

After dinner I went and got the new battery electric saw with the same 40V battery as my blower - really like this battery. Would love to figure out how to change it over to 120V somehow for the MacBook and phone while camping or "working from home". But I think that may involve too much math.

Anyway, here are the pics of the fully equipped I-m as a workhorse and the booty:
Image
Image
Image

Thanks for the help with the plug in question.

I really like the small battery saw.

After buying it at Lowes in South Philly last night, I was waiting for my car to charge a little more at the IKEA next door and unboxed the saw. I needed bar oil so I went to the IKEA and as the door was being locked, explained to the nice gentleman that I needed a small bottle of oil. He said it was right in there in the food area. Got organic thyme canola oil for $2.99 and poured that into the saw. Unplugged and drove carefully home doing 52 on the highway. Got near home at 10PM - on one mile of turtle and decided to go for it to the wood scavenging loop. Got some small pieces into the car and then saw a perfect 4 foot section. Sawed it with one hand! Awesome little saw. I wouldn't want to play with a cord with all that wood laying around, plus, lots of times I'm hazards on the side of the road near a corner or something and want quick execution.

There is at least 10 times more out there than my pile, maybe 20. And now I'm ready. I have my shorts and tank in the car for the ride home after work....excited!

Re: iMiEV as workhorse

Posted: Thu May 30, 2019 5:23 am
by bradleydavidgood777
Looks like the inverter is already made by another brand. So I could probably take apart one of the Kobalt 40V chargers and connect the wires from this brand's inverter.
https://www.amazon.com/Greenworks-Cordless-Power-Inverter-battery/dp/B07B7LBFVL

Re: iMiEV as workhorse

Posted: Thu May 30, 2019 7:41 am
by jray3
That GreenWorks inverter is only 300 W, so it won’t power either of your corded saws.

Re: iMiEV as workhorse

Posted: Thu May 30, 2019 11:36 am
by bradleydavidgood777
Yea, not for that, just for laptops, phones and stuff at the campground, mobile office, or power outages.

I have no desire to run corded saws anymore after trying the battery baby saw.

Re: iMiEV as workhorse

Posted: Sat Jul 06, 2019 8:05 am
by jray3
As our cars age discussion about them begins to sound like a bunch of old codgers discussing their health problems, i.e. “Can’t get around like I used to.” or “My charger is pooped!” Well, I thought a reminder of just how useful these cars are was is in order before this whole forum goes into the crapper!
Image
(Yes the hatch was able to close and the rear seats are still usable, though the seat backs were vertical.)

Re: Cargo space dimensions

Posted: Wed Jul 31, 2019 9:33 pm
by Bjron
I fitted 3x 180w solarpanels inside car :) trunk still closed ok.

https://prnt.sc/omsaa9


https://prnt.sc/omsacl

Under trunk if brokened AC Charger unit wll be removed will ger nice extra space. Or space for Setec Chademo charger ;) it will fit there without quick on clips. Need just connect cables dicectly to unit. Then charging can be done with cable near trunk door. Door little modded so it will close nicely without damaging cable. Miev trunk is just too small to keep Chademo charger there alltime.

Anybody tried car with 3.party dcdc unit? Maybe Small dcdc can be fitted inside inverter? There are some space inside. Easy mod wilö be put new dcdc 12v to top of inverter. So inverter aluminium frame will cool it down.

Re: Cargo space dimensions

Posted: Wed Jul 31, 2019 9:49 pm
by Bjron
Just like 40 bricks will fit to trunk..

https://prnt.sc/omsgqf