# EV gauge



## TTmartin (Feb 7, 2012)

Has anyone used a, JLD 404 Intelligent AH Meter?
Are they fit for purpose?
I've found them for $65 plus shipping from Lightobjects.com, sounds like a good price?


----------



## frodus (Apr 12, 2008)

Myself and others have used them. Pretty slick. Get a 75mV for it. IIRC, Jack Rickard detailed how you can set it up for a different A/mV shunt. I bought a JLD404 + 800A shunt, and it works pretty well for what I need it for.


----------



## Ziggythewiz (May 16, 2010)

Yup, I have two. Could use some more 

You can get whatever shunt you need there too.


----------



## TTmartin (Feb 7, 2012)

Thanks guys, ordered,
it's on it's way.


----------



## EV Myself (Apr 12, 2011)

Martin,
I have the JLD-404 in my TT. I have a picture in my Blog. I cut out some plastic out of the console and slid the meter in. The cover still works so I can hide it if I want. So far it is working fine now that I got the programming worked out. One note if you are going to use both the volt meter and amp meter you want the shunt on the most negative point of the pack because there is a common point. I have the it on the most positive side of the pack and the volt meter reads negative. 

Hope this helps
Alan


----------



## Roy Von Rogers (Mar 21, 2009)

And dont forget to install a dc-dc isolator, its also available on the lightobject site.

Roy


----------



## Ziggythewiz (May 16, 2010)

You don't need one. It's already isolated, I think all the JLDs are.


----------



## Roy Von Rogers (Mar 21, 2009)

JLD404 is NOT isolated.

Roy


----------



## Ziggythewiz (May 16, 2010)

And how do you know this, Mr Expert?


----------



## rwaudio (May 22, 2008)

Roy Von Rogers said:


> JLD404 is NOT isolated.
> 
> Roy


I have a JLD404 (blue) in front of me right now, powered up the 12v and HV sections ARE isolated.


----------



## Roy Von Rogers (Mar 21, 2009)

http://www.lightobject.info/viewtopic.php?f=9&t=322&hilit=isolation

This is from the site that sells the meter.

Roy


----------



## Ziggythewiz (May 16, 2010)

That's talking about wanting to power a ~10-30V meter with a 500V battery. He says it can read itself up to 30V.

If you follow what you posted there is a link for a similar meter showing usage: http://www.lightobject.info/viewtopic.php?f=14&t=159

There's no DC-DC converter shown. You don't need it. I'm running two of them, neither has ever seen a DC-DC, they work fine.


----------



## TTmartin (Feb 7, 2012)

EV Myself said:


> Martin,
> I have the JLD-404 in my TT. I have a picture in my Blog. I cut out some plastic out of the console and slid the meter in. The cover still works so I can hide it if I want. So far it is working fine now that I got the programming worked out. One note if you are going to use both the volt meter and amp meter you want the shunt on the most negative point of the pack because there is a common point. I have the it on the most positive side of the pack and the volt meter reads negative.
> 
> Hope this helps
> Alan


Thanks Alan,
Not sure where mine is going yet but maybe where the radio was as I am just going to have an auxiliary socket on the dash somewhere connected to the speakers to connect iPod / pad etc.

Ziggy,
I was just about to buy a dc-dc for isolation after watching the vidio on EVTV about the meter but if the spec states it's isolated then I wont bother.


----------



## Ziggythewiz (May 16, 2010)

Jack initially thought maybe it might need isolation, and what's another $20-30? So he had it in his 'kit'. It's not in the kit anymore (though I think the price stayed the same).


----------



## favguy (May 2, 2008)

Sorry to dig up this old chestnut, but I'm about to wire up my JLD404. It will be measuring both AH's and pack voltage.

Is the consensus now that this is definately isolated? I don't want it blowing up in the event of a slight frame leak for the sake of not bothering to fit a dc/dc! (that I already have)

Also, my shunt is also at the most positive point, so looks like I'll be showing a negative on the voltage too. This doesn't bother me, but can you still program the alarm relays to activate with a negative figure?

Paul


----------



## Ziggythewiz (May 16, 2010)

Yes, it's isolated. I've got a fat frame leak with no issues on either JLD404.

You can't get full performance with all negative numbers. I'll have to check the manual to see if it has specifics, but I recall it only did down to -200A with the leads reversed.

From the manual:
Voltage Input(V-Sn): Voltage input range
500V (-100~500V); 100V(-20~100V)

It shows alarm triggers with range down to -1999 but that would mean only -199 (or possibly -19) depending on the resolution you have set.


----------



## favguy (May 2, 2008)

Thanks for coming back to me,

Not sure I'm entirely following, presumably Ah counting can be done in the positive by switching the leads at the shunt to get a positive current flow reading? I want to set an alarm on this so when I get to 80% of battery capacity it takes action.

Other than this I want to measure pack voltage, and have the second alarm cut charger voltage at 175v (or thereabouts) in case the charger ever fails to terminate charge so I'd need to have it reading -175v at point of alarm due to the shunt being in the positive. 

I don't need the JLD to do anything else as I have other metering to measure Amps & Volts.

Will the above work then? 

Paul


----------



## Ziggythewiz (May 16, 2010)

According to the manual, the meter won't accept a voltage under -100. 

I'd try to squeeze the shunt in on the negative leg.


The shunt and alarms will probably work either way as long as you set it right.
What size cells do you have?


----------



## EV Myself (Apr 12, 2011)

The manual may say it will only work to -100 volts but it works. Up to 175 volts it matches my Fluk within 0.2 volts, just has a - sign. 

I'm still working on getting the alarms working, just have not taken the time so far.


----------



## Ziggythewiz (May 16, 2010)

If it works, go for it. When you start messing with the alarms, keep in mind they are triggered, not state dependent.


----------



## favguy (May 2, 2008)

Hmmm...

Moving the shunt isn't really an option at this point (at least not one I'm prepared to consider, far too much to rehash!) So I might just use the JLD for AH counting and alarm, as you say, shunt placement won't matter for this as it can be wired either way to get positive current flow. 

I can use a seperate voltmeter with alarm relay at the charger, 

Ultimately I'll be running either 100Ah or 180Ah lifepo4, at present I'm on lead.


----------

