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LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

37K views 30 replies 14 participants last post by  piwhy 
#1 · (Edited)
I've been thinking about using the Programmable Volt Meter from LightObject.com as a battery overcharge and over-discharge protector. I'm comfortable with my charger but I also like redundancy and since I charge at night in my attached garage so having another failsafe to help mitigate any potential risk of thermal runaway (FIRE!) sounds prudent to me. The recent talk about bricking of batteries in the Tesla got me thinking about my own EV and that I really have nothing on the discharge side to stop a slow drain from ruining my pack.

On the charge side:
I charge to a nominal voltage of 124.1 V and have observed this go as high as 125.1V during the CV charge phase. If I set the high voltage relay in the LightObjects voltmeter to say 0.5V higher than I've ever observerd (125.6V in my case) it can be used to disconnect my charger if this condition is ever encountered. The thing I really like about this method is that the worst case scenario is one of my batteries spikes 0.5V over its normal CV charge level. Reasonably I'd hope that this extra voltage is spread around to at least a few cells but regardless this should effectively limit the amount of power put into your pack.

On the discharge side:
I'm talking only about when the vehicle is parked. Say you leave the lights on for a few weeks :eek: or just are parking the vehicle for an extended period of time without properly disconnecting things and you need to keep parasitic loads from draining your pack down to dead. Set the low voltage relay for whatever low pack voltage value you're comfortable with. I'm thinking about 102.6V (2.85 V/cell). If I wire this relay in conjunction with some signal to indicate the car is off, not running, or current draw is below some small value I can run this to another contactor to disconnect my parasitic loads. Actually I'd just cutoff all my high voltage low current circuitry.

Ideally if the low voltage cutoff is triggered and everything shuts down. I want to just be able to plug in and everything will begin coming back up. I would probably need to pull some signal from the charger to energize the contactor that is between my battery pack and the vehicle parasitic loads.

I am wondering what the behavior of the device is when you power it off? Does it lose its memory? Am I going to have to reprogram my settings if it loses power? Do I need a small battery to keep it always on?

It sounds like a little bit of work but if it provides some added protection from burining my house down while my family is asleep (I know this is highly unlikely but without knowing the exact probabilities involved I'd rather err on the side of caution) and protects my batteries from accidently being allowed to drain down to nothing it seems like a cheap and straightforward solution.

Does this sound reasonable?
 
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#2 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)


I am wondering what the behavior of the device is when you power it off? Does it lose its memory? Am I going to have to reprogram my settings if it loses power? Do I need a small battery to keep it always on?

...
Does this sound reasonable?
Nope, it keeps its memory when powered off just fine. No reprogramming needed. Boy, that would be a PITA.

Sounds very reasonable. I was planning to do the same (at least on the charge side) when I get my conversion done.
 
#3 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

I got one to use in a bottom balancer that I'm building. I'm putting the volt meter, a 2a AC-DC converter, a ev200 contactor, a 12v muffin fan and a 250w 0.1ohm resistor all in an ammo can with some assorted wires, and creating a compact but capable bottom balancer. When I'm not using it I just close up the ammo can and everything fits nicely inside. When I need to bottom balance a cell, I open up the can and pull out two cables. One for the 110vac power and one to connect to the cell with a pair of clips. I'm glad to hear that the volt meter has a memory. I'd hate to have to reprogram each time I used it.
 
#4 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)



Does this sound reasonable?
I think it sounds perfect. Git er done. ;)

More and more ppl will go this way I think. It's just solid redundancy for bit of money... and a bit more work... .but well worth the peace of mind.
 
#6 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

m38mike,

Would you mind putting up a detailed, step-by-step walk thru of how you programmed that blasted thing? Mine is sitting on a shelf after spending a very frustrating couple of hours trying to decipher the instruction page on it.
Circle, right, right, right, up, circle
Down, circle, Right, up....

How detailed? :)
ya, i know i'm not m38mike.

But you're right, it is a really crappy instruction "manual". And the interface must have been designed by the same people that did the celllog8. It becomes easy only after you've run through it a few times.
 
G
#7 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

Then run through it a few times until your good at programming it. Thats how its done. It's never perfect the first time out. One step at a time.

Then once your done and good you can rewrite the manual and pass along the information. :)
 
#8 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

Stan,
Here's a link to the official Lightobject manual site for the volt meter. They have a 2 page downloadable sheet that helps a little but does not do much for me.
http://www.lightobject.info/viewtopic.php?f=14&t=157

I will go through the set up on mine again a few more times and try to write out some seemingly intelligent instructions. It may be this weekend before I get to it. I'm in the middle of building a new battery box out of oak for my Electro-Willys.
 
#20 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

Stan,
Here's a link to the official Lightobject manual site for the volt meter. They have a 2 page downloadable sheet that helps a little but does not do much for me.
http://www.lightobject.info/viewtopic.php?f=14&t=157

I will go through the set up on mine again a few more times and try to write out some seemingly intelligent instructions. It may be this weekend before I get to it. I'm in the middle of building a new battery box out of oak for my Electro-Willys.
Thanks for the link. I had code 0001 for the relays and 0039 for the display parameters figured out, but I didn't know about passcode 0089 (AC vs. DC), and it turns out, setting it correctly was the missing link.
 
#9 · (Edited)
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

Is it the same as the one on the EVTV store?
I was at a Starbucks when I asked the question, and couldn't pull up the Lightobjects page.

This is not the same one as on the EVTV store. This one does Volts only and as mentioned earlier in this thread, would be a great redundant shutoff for a charger. I toasted a couple of Headways when my charger ran amuck.
 
#10 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

I'm pretty sure the Lightobjects JLD 5740 Volt Meter is the same one that EVTV is selling. And I think I've got programming for it figured out. Mine's been working very well in my bottom balancer.

First, the keys. They look like this: [o] [>] [/\] [v] They are under that hard to open cover just under the number window. It hinges down.

All you need to have connected to program it is the 12v power source. Positive to screw 1, negative to screw 2.

First you need to tell the meter what voltage range it will operate in. It needs to get the password 0089 to know to do that. To do that power it up so you get 4 zeros. Now press [o] once. The decimal point dissappears and the first zero blinks. press [>] twice so the 3rd 0 blinks. press [v] until 8 appears. press[>] once so the 4th 0 blinks. press [v] until 9 shows up. press [o] to accept 0089.

Some criptic message appears. press [v] or [/\] to get to the numbers. they correspond to the numbers on the instruction sheet for the meter. 0-3 are for DC operation. 4-7 are for AC operation. Since I use it for single cell balancing I chose 2 which covers -2~+10vdc. Choose the code number which is right for your use. press [v] until you see "end" on the screen. press [o] to accept. Now your back at the readout screen.

Next you need to set the parameters for the meter. The password is 0036. press [o]. press [>] until the 3rd 0 blinks. press [v] to change it to 3. press [>] so the 4th 0 blinks. press [v] until it is 6. press [o] to accept. some text will appear. press [v] or [/\] until PuL appears. This sets your lower limit of voltage you want to read. Usually zero, but could be negative. press [o] to accept PuL and it will go to numbers. press [v] or [/\] to change the number to what ever you want your lower limit to be. press [o] to accept. the screen goes back to PuL. press [v] to change to PuH. This sets the upper limit you might measure. press [o] to get to the number. press [v] or [/\] to change the number up or down. I would double what ever max voltage I thought I might get to be sure you don't max out the gauge. once you have your number press [o] to accept. press [v] or [/\] to get to dot. This is how many digits are right of the decimal point. press [o] to go to the number. change the number with [v] or [/\]. press [o] to accept. next use [v] or [/\] to find FiLt. press [o] to go to the number. It should be 0, unless you have a lot of stray electrical noise around your gauge. press [o] to accept. use [v] or [/\] to find End. press [o] to accept. your parameters are set.

To set the relays in the gauge, the password is 0001. press [o] to start. press [>] until the 4th zero blinks. press [/\] to change it to 1. press [o] to accept. I use my gauge to help bottom balance, so I want to use the "upper limited" configuration because I want the upper limit of my cell voltage to be 2.708v. I only use the 1st relay. I set AH1 to 2.709 and AL1 to 2.600. With these numbers the balancer draws the cell down to 2.6v and shuts off. The cell will float back up over 2.709 and turn the balancer back on. The battery will go up and down for a while, and the balancer will turn on and off, until the cell simply stops floating somewhere between 2.700 and 2.708.

In general, Use the [v] and [/\] keys to change the settings you see on the screen. use the [o] key to start the programming, or accept what you have on the screen.

QUESTIONS???
 
#11 · (Edited)
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

I'm pretty sure the Lightobjects JLD 5740 Volt Meter is the same one that EVTV is selling. And I think I've got programming for it figured out. Mine's been working very well in my bottom balancer.


QUESTIONS???
Here is the one that is being sold on the EVTV.me store:

http://www.lightobject.com/Programmable-Digital-AH-meter-Ideal-for-battery-monitoring-P278.aspx

The model number is JLD404 and it is $69 on the Lightobjects site and $175 on the EVTV.ME store. That appears to be a different model number than the one that is the subject of this thread. The EVTV meter includes the meter, a shunt. a DC to DC converter to isolate the power supply voltage, and a manual written by Jack Rickard. There is some value added with the EVTV version but I am always looking for the bargain. Thanks to M38Mike there are some instructions. I already have a DC to DC converter so all I need to get is a shunt and I am out of pocket for less than $100.
 
#12 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

ricklearned, you're right, the one Jack sells has the ampere gauge as part of it. This volt meter is just that, a volt meter, plus a little bit more. BTW, I talked with Electric Conversions about using one of these with my charger to make sure I don't overcharge. I've got a PFC2000 that I'm sending in to get reprogrammed for my new pack. They haven't told me if I'll be able to use one of these as a 'fail-safe' backup to keep from overcharging.

Mine is working well in the bottom balancer I built. But I notice that after I pull the cells off the balancer, within a day or so they have floated up about 1/10th of a volt. So I'm thinking about buying another one of these, and creating a very low power bottom balancer with it. Then I'd put all the bottomed cells together in parallel and connect them with this balancer to keep them all at the same voltage until I'm ready to put them all in series in the vehicle.
 
#18 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

It's interesting that they call them passwords, as if you could change them or something. I don't think the manuals are too bad, but obviously they leave info out and I have a hard time wrapping my head around the alarm (relay) curves...that's an implementation issue though, not documentation.

I wouldn't consider a cheap smart device to be a fail-safe, maybe a redundant safety device. I haven't noticed any issues with the voltmeter portion of mine (404) but the AH counter is frequently glitchy.
 
#19 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

gdrwin: I do.....oops. I use 12dc to operate a 30 amp Brumfield relay which operates a LED or breaks the wires from the Elcon that were supposed to go to a BMS.

That way it sees a few MV.

Miz
 
#22 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

I was thinnking of using the volt meter as a Precharge controller.

Using one of the relays as the NC for the precharge resistor.
and the other Relay as NO to pull a 12v relay for the main contactor.

This way I can set the voltage exactly as I want so it swicthes of the first relay and on the second one when the controller has precharged.

Any thoughts?

Best Regards
/Per
 
#23 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

Sure. Shouldn't be tough as long as your shunt is on the controller side of the contactor.

I may look into using that too. I have a manual precharge that takes it to 85 or 90% but it wouldn't be tough to add an additional precharge circuit that would kick in at 80 and take it to nearly 100.
 
#24 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

Dont really know what you mean by the shunt being on the controller side.

http://www.lightobject.com/Programm...th-dual-control-Good-for-HHO-System-P408.aspx

Is the one I plan to use, it has no shunt for current sensing, it's just a volt meter.

I could set it up to sense the voltage over the contactor and when that comes close to 0v at precharge i can engage the main contactor and disconnect the precharge resistor/s.

I would power it with the 12v that now engages the main contactor so it would only turn on when I turn ignition on. And at that point it will have the precharge resisors connect over the contactor and therefore the voltage difference over the contactor would fall down to the point where it is safe to engage the Main contactor.

My current sensor(hall effect) is placed almost mid pack.

Regards
/Per
 
#25 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

Sorry, lots of us use the 404 which is an AH couter as well.

You could have it just across the contactor, but that'd be a waste of a nice meter. Just put it across the full pack, near +- on the controller, so you can see your pack voltage as read by the controller. It will still do what you need for the precharge but will be useful beyond that.
 
#27 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

Sorry, lots of us use the 404 which is an AH couter as well.

You could have it just across the contactor, but that'd be a waste of a nice meter. Just put it across the full pack, near +- on the controller, so you can see your pack voltage as read by the controller. It will still do what you need for the precharge but will be useful beyond that.
Yes I know it would be a waste.
But hear me on this.
The pack voltage will vary depending on SOC. Therefore you could end up in a situation where you would not consider the precharge done if you use a fixed value as a precharge ready.

If you on the other hand use the voltage over the open contactor you know that precharge is always finished when that voltage is below a certain value.




@3wheeler:

Check Jacks online store.
He has the manual for the JLD404 and the 4-range voltmeter there that you can download. It is much better than what lightobject provides.
It could help a bit even if the model you have is the one described in the documents.


Regards
/Per
 
#26 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

This is a very old thread, so I hope someone is monitoring it and can assist me.

I recently bought this meter as a Ammeter for my electric trike to see the current draw on the motor. I bought it on a recommendation from someone on this forum and found it on ebay:

http://www.ebay.com/itm/350263616004?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

It was listed as a:
Blue AC/DC Dual Control 5A 500A Current meter Ammeter

And It actually says:

Digital Ammeter
Model : JLD5740TA on the sticker.

But It came without instructions, only referring me to a website for a manual; which I downloaded but is not very useful. At least I know to connect my + 13.2V to pin 1, and - 13.2V to pin 2 to power the unit.

But I can't figure out which of the other 14 pins to use with the 500 Amp 75mv Shunt? I suppose that one end goes to pin 8 ( Common ) but where does the other side of the shunt connect to, and how do you program this thing to display Amperage?

can anyone advise me?
 
#28 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

Thanks Pn Dawn,

You are correct; the JDL404AH is VERY Similar ( if not identical ) to the lightObject's one. I found the manual at evtv.me and it is very well written.

Got it now, I know what to do.

Thanks again
 
#31 ·
Re: LightObjects Programmable Volt Meter (for charge & battery slow drain protection)

I've recently found an interesting alternative to the expensive and non-user-friendly JLD 5740 programmable voltmeter.
I ordered few multifunction voltmeter like this one : http://www.aliexpress.com/store/pro...eter-detection-control/632227_2020372081.html
It make exactly the same job as the JLD5740, even if the voltmeter display is less accurate but it's cheaper and really easiest to configure !
 
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