Curtis SOC 906 Questions

[kernal]

He already has the digital meter installed. Now he can use both simultaneously.
Hope he reports on what he sees in the future. I know other people have done this but nobody ever comments on the results. In my situation, random checks with a hand held meter have been sufficient or I would have done it.

[Sergio]

Originally Posted by geonjay

The meter is ordered. The final price was $61 shipped. I currently have my voltmeter connected to my key switch and a black/ground wire coming out of my dash harness. I was thinking of going ahead and running a new wire directly from the pack to my dash just for the SOC and volt meters - is it ok for them to run off of the same wire pair? Which gauge wire should I run? Is there any reason I shouldn't continue to use the keyswitch, and black/neg leads I'm using now? Can I connect the SOC to the always-on side of the keyswitch for the constant power AND on the switched side so the display is only on when the key is on?

Yes, that is the correct way to connect it.

The meter needs a constant connection to the battery pack so it can sense when the batteries are charged and reset the meter.

While Scottyb is correct that if You got the version without the "Memory Profile" the meter resets once it detects a charging voltage pattern, the meter is considerably more intelligent than what was described.

IF You have an aging pack that can only charge to 49.5v, the meter will not show 100%, the volts per cell required for Full and Empty are defined for each of the model numbers.

Some folks find it easier to have a meter that shows a more familiar "gauge" style capacity approximation that does not vary as You press the pedal and load conditions change.

I use a digital voltmeter because I like to see how my pack performs under different load conditions, but those SOC gauges when properly used will work fine.

Look at the manual for the specific volts per cell (letter code 4 of Your part number), and match it against the published tables for approximate battery SOC charge based on voltage.

That will give you a pretty good idea about the pack SOC represented by the leds that are illuminated.

Edit: I see You posted while I was typing, You got a good understating of how it works, just make sure Your wife knows "empty" will mean "stranded" in that model # profile.

[scottyb]

Originally Posted by geonjay

Is there a better "gas gauge" that you'd recommend? I'm doing this to appease my wife...she really wants that style of gauge so she won't have to remember/look-up the voltmeter readings.

The distributor just emailed me to let me know that the "P" discharge profile (2.08-1.98V/C) is on longer available - per Curtis that option is no longer being made. So I went with the more dangerous, but realistic option "L" - (2.10-1.92V/C).

An old analog meter may work best for her. They have green and red zones, so she can see when to recharge. Or you can simply explain that the device you have is the BEST state of charge meter and she needs to plug the 48v golf cart in before it drops down below 48v. We all struggle with this with our wives and children. I actually stuck a label maker label on one 42v cart to remind everybody when to have it plugged in...
You probably made the simple male error of sharing your interest in the live voltage readings with your spouse....showing her the SOC to voltage chart and giving her a copy to memorize. The key is to make reading the meter real simple. Just explain that above 48 keep driving. Close to or at 48v plug it in.

[kernal]

Just to be clear, when installed from the factory the gage is always on (hot) but not lit unless the key switch is on. In EZGO speak this means the gage lights up when key is on and a direction is selected. I have seen CC and Yammies operate similarly but not always. DIYers and shops don't all do it the same way.

An additional benefit of this installation is that you can tell when the cart is on and ready to go. I am grateful for this when grand kids are around. Golf carts attract small children and dogs.

[geonjay]

Thanks, as always, for the input!

The distributor has written back yet again...they don't have ANY of the 48v Curtis meters in stock. Here's a snippet of the response:

The trouble with my stock in general (as I now see) is that I do not have any 48V meters. 906's are tough as they are not a huge seller anymore. I would recommend looking at the GDI "L" series BDI and trying to find a match there. If I do not have the one you want in stock I can get it within a 2-3 week lead time. I also am not subject to minimums like with Curtis.

After going directly to GDI's site, I can see that none of their "stock" meters are going to have a discharge profile/curve that's close enough to the real curve of my batteries - so what's the point. I'll cancel that order and keep hunting.

I like the idea of an analog meter...is there one that offers the smoothed average of a BDI? I'm still open to opinions about other BDIs that work reasonably well.

[Sergio]

I thought all analog meters fluctuated with load as do the digital voltmeters, maybe Scottyb can post the model number he mentioned that works more like an SOC meter.

[scottyb]

Originally Posted by Sergio

I thought all analog meters fluctuated with load as do the digital voltmeters, maybe Scottyb can post the model number he mentioned that works more like an SOC meter.

Well yes the needle does swing under load... I was thinking of the common old fashion meter which allows one to see the current lowest operating voltage and allows any simpleton to read the standing still voltage in terms of green go or red stop (stop and charge)

Personally if this became an issue in my camp - I would put both types of meter side by side... the next cart can just have the digital

[geonjay]

Ok...I'm hardheaded..I know. I went with the Pro12-48R from ProPower Meters because the battery curve matched Trojan's specs. It was a bust though. The meter came on and worked fine, it reset when charging and seemed to work great. I drove around our hilly neighborhood for about 5 minutes and the meter started showing that my batteries were DEAD (flashing red and yellow LEDs)..I took it home and let it sit for a while..my digital meter showed 49.7V but the new fuel-guage kept on blinking.

The new meter "averages" the reading over 150 seconds...but driving around my hilly neighborhood (which is the typical use of this cart) keeps the pack under load for longer than that, so the average reading from the pack is very low, which trips the meter into flashing death mode - and it won't reset until the pack is charged. I contacted the manufacturer with my situation and asked about wiring the meter through the keyswitch - at least then I could kill the power when needed and have it reset. He responded very quickly and said that even going through the keyswitch the meter will require ~51v to "reset".

Am I just screwed on this endeavor? There has to be a fuel gauge type battery meter that WILL work for the newer battery packs ("hot" packs..lots of buzz words)? I wouldn't even mind the analog meter like what ScottyB posted...but I can't even find any of those that match the expected curve.