How I'm combatting rising fuel prices with solar.

[Biggkidd]

Need a little help from someone smarter than I am. lol I know that wouldn't take much! lol

I inherited a couple Fluke meters some while back. With all this battery stuff going on I decided to dig them out. Got new batteries in and the multi meter reads different than my trusty old NOT CHEAP HF multi-meter. I bought their most expensive unit many many years ago and have used it since. Now this Fluke meter is probably about the same age but Fluke is supposed to be one of the best if I'm not mistaken. How can I find out which one is correct? My old HF meter reads these cells at 3.37 - 3.38 and the Fluke reads them at 3.412. I KNOW .04 of a volt isn't that great a difference but I would like to KNOW not guess. Any ideas?

 

[Neb]

Need a little help from someone smarter than I am. lol I know that wouldn't take much! lol

I inherited a couple Fluke meters some while back. With all this battery stuff going on I decided to dig them out. Got new batteries in and the multi meter reads different than my trusty old NOT CHEAP HF multi-meter. I bought their most expensive unit many many years ago and have used it since. Now this Fluke meter is probably about the same age but Fluke is supposed to be one of the best if I'm not mistaken. How can I find out which one is correct? My old HF meter reads these cells at 3.37 - 3.38 and the Fluke reads them at 3.412. I KNOW .04 of a volt isn't that great a difference but I would like to KNOW not guess. Any ideas?

HF = harbor freight?

To answer that question you will need a known voltage reference traceable back to NIST (National Institute of Standards and Testing). More expensive than the meters and they need to be calibrated regularly.

Before zener diodes were invented scientists would use chemical cells. For a given cell type the cell voltage is a function of air pressure and temperature. Is it worth the trouble?

Where both meters on the same range setting ?

Assuming both were on a 10V range...

0.04 V on a dull scale range is only a 0.4% difference. Not bad.

Digital multimeters have a spec that describes how many digits can be trusted. 3.5 digits is ok for a budget meter. 5.5 digits for highly accurate meters are available but require being warmed yp for a certain amount of time and need to be calibrated regularly to maintain that status.

Note

The "x.5" in 3.5 or 5.5 talks about the least significant digit that is always flickering.

Many electronic engineers care about 3 digits for production work. Scientist want 4 or 5 digits.

Sea story time

I wrote an application used to control the furnaces used to grow the crystals used to make semiconductors. It needed to control a temp of 1072 degrees C plus or minus 0.1 degree C for weeks. That required 5 digits!

Back to your meters...

Can you swap the leads between the meters?

0.04V could be lost in the meter leads.

I would guess that both meters are performing well as designed.

Ben

(Retired senior MEASUREMENT and automation software architect)

 

[Supervisor42]

HF = harbor freight?
Back to your meters...

Can you swap the leads between the meters?

0.04V could be lost in the meter leads.

I would guess that both meters are performing well as designed.

Simply twisting the connections where the leads are plugged into the meter could make that much difference at that low of a voltage.
I would trust the higher reading.
If meters are 'off' by a little bit, they read low.
We were fortunate and only needed to measure the difference between 0v, 208v, 240v, 480v, and 512v.
Voltage under full load verses no-load was most common.
"Live" or dead was the most important measurement.

 

[Biggkidd]

Okay I won't worry about it then I knew it was just a TINY difference. Yes HF= Harbor Freight. IIRC I paid over $100 for it YEARS ago. This Fluke meter was probably around $500 in the same time frame. I wanted a Fluke back then just couldn't stomach the price tag for what I used meters for. Much like @Supervisor42 said.

 

[Biggkidd]

Thanks Guys!

I am going to order a BMS tomorrow. That's going to put a larger kink in the finances than I was planning on. Also cuts down the amount of dollars saved over just going and buying a 100-105 AH 48V LifePO4 battery assembled and ready to go. BUT then again they only have a 100 amp BMS I'm leaning toward a 250 amp fully programmable BMS. Even at that though the savings are still going to be around $700-$750 from buying a 2,000 cycle LifePO4 battery. So I think I'm coming out alright considering these cells are rated for 3500 cycles and I'm getting twice as much continuous BMS amperage ability. Probably way overkill but that's the way I like it! lmao

 

[Bacpacker]

BK, Ben's description is very accurate. We have to have all of our standards calibrated regularly. Our meters go thru once per year. Our Fluke's rarely drift at all.

What model is your Fluke meter? We use 87's, 287's, and 289's. The 87 is 3.5, the 200 series are 5.5 digits, much higher quality. I have 2 87's myself and never saw an issue with either one.

 

[Biggkidd]

Picture is worth a thousand words right.

 

[Bacpacker]

The pic didn't come thru clearly enough to read the number. What is the number beside the yellow box that says Fluke? It looks like maybe a 70 something?? Older model for sure

 

[Biggkidd]

Fluke 16 multimeter is all it says there. You can click the pick to see it better.

 

[Biggkidd]

That old centech HF meter has always done all I needed and more. Both of them have temperature functions as well. Probably a lot of other functions I've never needed as well.

 

[Bacpacker]

I've never saw a model 16 before. It does look to be in good shape and has a rubber protector around it. I'd bet the meter is good.
Someone mentioned swapping the leads, that would be a good idea if they fit

Centech is a decent brand as well

 

[Biggkidd]

I've never saw a model 16 before. It does look to be in good shape and has a rubber protector around it. I'd bet the meter is good.
Someone mentioned swapping the leads, that would be a good idea if they fit

Centech is a decent brand as well

It's also been kept in the case made for it that's under it in the picture. I have ZERO complaints with my old centech meter at all. It has always done well enough for rough & ready mechanic work that I use it for 99.99% of the time. .04 difference between them isn't bad at all I wouldn't think for general work not the stuff like Ben was talking about.

 

[Bacpacker]

It's also been kept in the case made for it that's under it in the picture. I have ZERO complaints with my old centech meter at all. It has always done well enough for rough & ready mechanic work that I use it for 99.99% of the time. .04 difference between them isn't bad at all I wouldn't think.

My guess is they are both well within spec if you had them calibrated. The leads would be worth checking though, even down to the connectors. They do go bad sometimes. We usually swap ours every 2-3 years at work just to be safe.

 

[Biggkidd]

Generally speaking most of what I use a meter for is to see if power is getting where it's supposed to and that the voltage is about where it should be. IE: a 12 volt system should have around 13.8-14.5 running volts and you want to make sure whatever is getting 13-14 volts and not 0 or 6 from a broken or frayed / corroded wire or connection. Like I said rough & ready. lol

 

[Neb]

Picture is worth a thousand words right.

View attachment 87851

I have a 1/2 dozen of the center tech meters. One of them has a bad 200 VAC range. 110 reads 10V. The rest of them are fine. I like the thermocouples.

I have used all of the functions except the semiconductor input. Did use that on my old Radio Shack version that since died.

I grabbed another half dozen of Chinese clones from Amazon. They were only about $15 each.

Why so many meters?

I have them scattered about. One with reach now.

I am also the go-to person around here for
electronic issues. I lend out meters so I don't have to do the work.

Sometimes they get returned.

I also have a stack of meters new in the boxes stashed in a Faraday cage.

Ben

 

[viking]

On the 9th we had a tree drop across our power line and have been running on the backup solar system, electrician is supposed to come Thursday or Friday next week, he says our meter base and panel are way out of date, it's sounding like it may be a bit spendy, anyway last night the inverter took a short break at 2:45 AM, probably the automatic safety devices shut it down, the Magnum Energy inverter has thermal over temp cut offs, probably the FET's were getting too warm, it didn't take more than a half hour and the inverter came back on. Earlier yesterday I checked the meters and the system was using up to 44 amps discharge, both of the refrigerators were running as well as a small chest freezers that time. Today it's cloudy with a bit of rain so we aren't going to get a strong charge out of the solar array, haven't been up to the solar shed yet, but in the past I've seen close to 15 amps on a day like this, we're not using any lights or other electrical devices so as to keep current draw to a minumum. This will make a good test of just how good our system is working.

 

[Biggkidd]

Got the BMS ordered. I fought with myself bigtime on this one and ended up ordering the 250 amp BMS. It cost twice as much as one that more than likely would have done the job just fine. But I know this one should be able to handle more than I could ever throw at it with my battery and motor setup or any other motor I may possibly get in the future. Hopefully it will last as long as the battery cells should! Bad thing it could be up to 6 weeks or more before it gets here. UGH the slow boat from you know where!

I just added up the total battery cost ouch! It did however come out to be almost exactly the same as buying lead acid batteries. Still it was more than I wanted to spend. Lead acid replacement batteries were actually one dollar more without tax over what I paid including tax.

 

[Biggkidd]

I've been wanting to ride the golf cart down to the river about 4 miles from here since I got it. Wasn't really sure it could make it there and back for two reasons first the batteries and second the road condition. In fact I am positive the batteries would not have made it the first few weeks I had it running. These batteries have gotten steadily better with the long slow all day charging. I made it there and back and didn't even have a full charge when I left here to go. I am continually impressed with the places that little cart can go with those tiny tires. Surprisingly I never had any trouble at all. I did however get eaten ALIVE by the dang May flies they were out in force and it would seem each and everyone is addicted to my blood! The batteries are pretty well dead now. But I rode the cart out to the road with my daughter to get her truck about 10 last night with head lights on and used it several times this morning for the great key hunt after doing chores. I usually leave all the keys in whatever they go to. Well they got moved at some point and I couldn't find any of the old truck keys to the three trucks we don't drive because they are broken. lol But I needed the gate key to get down the road to the river. Anyway these batteries are doing one heck of a lot better than they were when I got them. When I got the cart going it hardly could make the chore rounds without being flat dead. Between last night and today I bet I did nearly fifteen miles on ROUGH HILLY logging roads with no more than the solar panel charging. I did plug it in when I got back a little while ago since I have to go back out to the end of the road later and get my daughter after work.

 

[Biggkidd]

Can anyone tell me if the newer carts with controllers use less power than these old resistor coil carts? I would think they would since these literally burn off excess power to control the speed?

Found out tonight since I remembered to look LOL that it takes 20 amp hours to go to the end of the road with a passenger and back with two. That's a 4 mile round trip with a moderate to heavy load. I wouldn't mind cutting that back some if possible. Also having the ability to ride along a bit slower than this one will go would be nice. It's funny but sometimes I want more speed and more often than not less speed is better here. Dang roads & trails are almost as rough as cross country can get.

 

[Supervisor42]

Can anyone tell me if the newer carts with controllers use less power than these old resistor coil carts? I would think they would since these literally burn off excess power to control the speed?

Oh gawd yes!
Any heat you feel is power you are wasting.
Learn also about regenerative braking and auto-decel.
If you have to touch the brake pedal, your machine sux!!!
That wasted power belongs back in the battery.
A lot has changed since 2004.
I can't dox myself, but we brutally tested the technology in other equipment.
Detailed logs were kept on run-time, battery power consumption/charging, any problems they had, and these units were run around the clock, every day.
Edit: And if your drive motor has carbon brushes, they generate a lot of heat.....which is power that belongs in the battery.
We easily helped them find what worked, and what did not.

All of this, we offer up to you today.......on a silver platter.

 

[Biggkidd]

Oh gawd yes!
Any heat you feel is power you are wasting.
Learn also about regenerative braking and auto-decel.
If you have to touch the brake pedal, your machine sux!!!
That wasted power belongs back in the battery.
A lot has changed since 2004.
I can't dox myself, but we brutally tested the technology in other equipment.
Detailed logs were kept on run-time, battery power consumption/charging, any problems they had, and these units were run around the clock, every day.
Edit: And if your drive motor has carbon brushes, they generate a lot of heat.....which is power that belongs in the battery.
We easily helped them find what worked, and what did not.

All of this, we offer up to you today.......on a silver platter.

Haha I've worn out the brakes already! So what are my options? I want to keep all the old operating system intact but not necessarily in the cart. This thing is a 1988 and the brakes SUCK for certain! Any tips are greatly appreciated! Money is an issue so . . . . .

I like the old stuff is mostly fool proof but I also like high efficiency so if I can swap out the old stuff without damaging it and keep it for a rainy day so much the better. Can you point me toward what I need by any chance? I see all kinds of high end kits but they are sadly way out of my price range any time in the near future. Some good low dollar options are what I need here.

ETA:
Had to look up dox so never mind don't want anyone to get in trouble.

 

[Supervisor42]

Haha I've worn out the brakes already! So what are my options? I want to keep all the old operating system intact but not necessarily in the cart. This thing is a 1988 and the brakes SUCK for certain! Any tips are greatly appreciated! Money is an issue so . . . . .

I like the old stuff is mostly fool proof but I also like high efficiency so if I can swap out the old stuff without damaging it and keep it for a rainy day so much the better. Can you point me toward what I need by any chance? I see all kinds of high end kits but they are sadly way out of my price range any time in the near future. Some good low dollar options are what I need here.

Not possible, without completely remanufacturing it.
It would look like this when you finished:

Engine Type
Single 48-Volt, High-Efficiency, AC-Induction Motor
The RANGER EV features a powerful 30 HP motor, box capacity of 500 lb and towing capacity of 1,500 lbs, making it more than capable for tough tasks.

 

[Biggkidd]

That looks about right. I've never been afraid of building what I want. I've built several vehicles over the years. One was a C30 dump truck and another was a 9 second street car just two of the more interesting builds I've done. Both built from the frame up by my own two hands. The bed on that's a little shorter than mine will end up being. Provided I can ever find the materials I need. I'd also like my version to be 4x4.

 

[Biggkidd]

I pulled a few logs with it this morning nothing real large with the largest being about 8 inches on the big end and twenty feet long. I can officially say it pulls them a whole lot better and easier than a garden tractor does. Changing the batteries out for a single lighter battery will probably reduce that ability by reducing the traction weight. Which is no issue as I have several better ways to move larger things. But I do enjoy the quiet and lack of diesel smell. All in all this thing is a whole lot more capable than I ever dreamed possible.

 

[Biggkidd]

Got to watching an old movie late last night and while I was at it I went ahead and put the cells in the battery case. WoW talk about a perfect fit. I used some 1/8th" high density foam mat to sandwich the cells tightly inside the box, one piece on each end. The foam was packing material from the lift kit. lol None of the cells actually touch the case anywhere. Lord help me if they ever need to come back out they are in tight. I still need to figure out some way to lock them in place side to side where there's a 1/4 inch gap between the cells and walls for airflow. If anyone has any ideas I'm all ears.

 

[UrbanHunter]

Got to watching an old movie late last night and while I was at it I went ahead and put the cells in the battery case. WoW talk about a perfect fit. I used some 1/8th" high density foam mat to sandwich the cells tightly inside the box. The foam was packing material from the lift kit. lol None of the cells actually touch the case anywhere. Lord help me if they ever need to come back out they are in tight. I still need to figure out some way to lock them in place side to side where there's a 1/4 inch gap between the cells and walls for airflow. If anyone has any ideas I'm all ears.

In the old days the hobby stores sold 1/4X1/4" balsa or spruce strips for models. The would be light and relatively sturdy, a little expensive but that was what came to my mind.

 

[Biggkidd]

In the old days the hobby stores sold 1/4X1/4" balsa or spruce strips for models. The would be light and relatively sturdy, a little expensive but that was what came to my mind.

I was thinking paint paddles but I can't block the airflow. I also need to figure out how to maneuver the cells just a little to get them aligned better.

 

[Magus]

PVC pipe strips, the bonus is, if you see the color change, something is getting hot!
Maybe cut out some rubber squares from a tire and glue them on?

 

[UrbanHunter]

I was thinking paint paddles but I can't block the airflow. I also need to figure out how to maneuver the cells just a little to get them aligned better.

Paint stir sticks cut into thin (1/4") strips for spacers, attach to 1 battery with double sided tape, align with spacers with the airflow, 2 or 3 strips per battery. 2 or 3 stir sticks should do the job...

 

[Biggkidd]

That's sort of what I have been thinking. Except there is no way the cells are coming back out to tape to. So whatever I use needs to be stiff yet flexible enough to bend past the box's lip and then push down the sides. The cells are only 1 1/4 thick so maybe one right down each outside edge.