SOC meter.

[JohnnieB]

Originally Posted by simple man

Actually the resistor across the solenoid lugs passes more current than this gauge! .......................I read an article on Curtis SOC's that stated how they measure voltage change over a period of time and switching it on and off would upset this sequence.................

An analog SOC meter is simply an expanded scale (offset zero) voltmeter with a scale printed in State of Charge mumbo-jumbo instead of volts.
Assuming the typical 1mA meter movement was used, it has an impedance in the 50,000 Ohm range while the resistor across the main terminals of your solenoid is probable around 250 Ohms.

I think the Curtis meter being referred to is a Bar-Graph type that self calibrates on the max voltage reached when the batteries are on the charger.
If it is turned off, it either comes back on with your current battery voltage being a full charge or a factory default value.

There might be a "Zero" adjust screw on the back of your SoC meter, but probably not a Full Scale" or "Range" adjustment.

When the battery pack is fully charged, you can put a 10K pot in on one of the SoC meter leads and with a DVM, find out what the volts at the various lines actually are.

[JohnnieB]

Originally Posted by yurtle

Thanks.
I already have wires for my roof mounted tail light, dome light, and high voltage wig-wag strobes, as well as stereo power and memory wires, inside my roof. I used a BIG (mad scientist) rare earth magnet to guide a pull string with a nut attached from where they enter the roof to their destinations. I was hoping to avoid this, because so far, all of my wires are hidden. There's no good way to enter the rear supports without day-lighting the wires first.

If you only have switches in the B+ wires, you might be able to reduce the wire count by running a single, but larger, B- wire.

Also, check out the various current draws, some of the wires might be bigger than necessary.

Set the Tesla Coil in the bag rack and nobody will notice any exposed wires.

[scubabud]

Or you can just purchase a Digital Meter from ScottyB that will show ACTUAL voltages through your driving pleasures... 2 wire hookup, water proof and the most accurate way to view what's happening with your battery pack AT ALL TIMES... No guess work

PS I have a very PRETTY LED meter that looks great... and would give a fair report of pack voltage. But when the red LED's are blinking off and on showing 10% charge left, my digital meter shows over 48 volts... woops...

Click on my signature showing Street Legal and you'll see a picture of it!

[simple man]

17 hours after the charge finished.
This is 37.78V on my DMM!

[yurtle]

Originally Posted by JohnnieB

If you only have switches in the B+ wires, you might be able to reduce the wire count by running a single, but larger, B- wire.

Also, check out the various current draws, some of the wires might be bigger than necessary.

Set the Tesla Coil in the bag rack and nobody will notice any exposed wires.

I'm anal, and switched both conductors on the dome and tail lights (outdoor rated DPDT - overkill, I know), but they're tiny. Wig-wags are HV wires, with appropriate insulation. Stereo is two 12 AWG, and a smaller memory wire. I could eliminate two tiny wires if I wanted to, but it took a full day to pull them, so that ain't gonna happen (now anyway). I'll either pull the new ones in the back, or scrap the wig/wags.

I'm gonna add a 48 v -> 12 v reducer, so my whole wiring scheme is gonna change, so I still might do what you suggested.

Truck bed liner on the battery rack is dry and two new battery locations have been completed. Need to change rear end oil, lube my wheel bearings, adjust brakes, shorten my FNR, install new 4855 and solenoid, then I'll be ready for a test drive.

Toys like speed-o/volt meter/temp/clock, stereo, wig-wag, neons, head and tail lights can wait.

[simple man]

If you know any friends that are electricians, see if you can borrow a fish tape. It makes pulling wire a snap!

[yurtle]

Originally Posted by simple man

If you know any friends that are electricians, see if you can borrow a fish tape. It makes pulling wire a snap!

I have a fish tape. I also have several friends that are licensed electricians and they are all hooked on my rare earth magnet trick. Fish tapes don't do a pretty job on exterior walls with insulation. The magnet pulls the pull-string and nut to the inside of the drywall, easily cruising past the insulation.

If you've never seen a rare earth magnet, they are incredibly strong. I had two that were 2-1/2" x 2-1/2" x 1-1/2", and ended up giving one away. It was too scary having two in the same house (with beer).

[scottyb]

If you are wanting to pull wire thru a tube or pipe try using a vacuum to suck a string thru first (tie a bit of torn up plastic bag on the end) then tie that to your wire or if it's big stuff tie the string to a rope then pull it and tie to the wires. You never know when these tricks will aid ya

[yurtle]

Originally Posted by scottyb

If you are wanting to pull wire thru a tube or pipe try using a vacuum to suck a string thru first (tie a bit of torn up plastic bag on the end) then tie that to your wire or if it's big stuff tie the string to a rope then pull it and tie to the wires. You never know when these tricks will aid ya

Yep. Magnets don't work in tube steel. I was talkin' about through the roof. Gettin' the pull string in was easy. I had more wires than the NEC allows! Soap helps lubricate the wires, but there are several bolts that have to clear.

[JohnnieB]

Originally Posted by simple man

17 hours after the charge finished.
This is 37.78V on my DMM!

Ouch!!!! That is quite a bit off. Line at top of green segment should be about 38.20V

Fortunately, it is reading high, that's easy to correct. Just add resistance in series until pointer falls just below top of green.
My guess is about 5% of the ohmic value the meter measures terminal to terminal.
(Tech note for Geeks and Nerds: Yeah, I know that will change the span, but this is an expanded scale voltmeter, so it won't be much.)