There go 30 microamps, down the drain...

[Turbo DV8]

I have an Inova 24/7 headlamp which I put away several months ago with a partly-used CR123 battery. I went today to turn it on, and no joy. Measuring the battery, it was completely flat, as in a few millivolts. I put in a fresh battery, made sure the light was off, and measured for any drain at the battery cover. Funny thing, the DVM measured 30 microamps, then quickly went up to 90 microamps, then back down to 30 microamps. This cycle repeats with a period of about ten seconds. I assume I have found the culprit of the drained battery. How long would it take to drain a CR123 cell under a 50 microamp or so load? Any thoughts?

 

[LukeA]

Re: There goes 30 microamps, down the drain...

I have an Inova 24/7 headlamp which I put away several months ago with a partly-used CR123 battery. I went today to turn it on, and no joy. Measuring the battery, it was completely flat, as in a few millivolts. I put in a fresh battery, made sure the light was off, and measured for any drain at the battery cover. Funny thing, the DVM measured 30 microamps, then quickly went up to 90 microamps, then back down to 30 microamps. This cycle repeats with a period of about ten seconds. I assume I have found the culprit of the drained battery. How long would it take to drain a CR123 cell under a 50 microamp or so load? Any thoughts?

If the cell is 3V 1300mAh, then a full one should last almost 3 years on a ~50uA load.

 

[Turbo DV8]

There goes 30 microamps, down the drain...

Sorry, I should have posted this here instead of LED forum...

I have an Inova 24/7 headlamp which I put away several months ago with a partly-used CR123 battery. I went today to turn it on, and no joy. Measuring the battery, it was completely flat, as in a few millivolts. I put in a fresh battery, made sure the light was off, and measured for any drain at the battery cover. Funny thing, the DVM measured 30 microamps, then quickly went up to 90 microamps, then back down to 30 microamps. This cycle repeats with a period of about ten seconds. I assume I have found the culprit of the drained battery. How long would it take to drain a CR123 cell under a 50 microamp or so load? Any thoughts? Anybody else have a 24/7 and can measure for any drain when off? Thanks.

 

[LEDAdd1ct]

Re: There goes 30 microamps, down the drain...

What is causing the load?

 

[drmaxx]

Re: There goes 30 microamps, down the drain...

CR123 has typically 1500 mAh.
@ 50 microamps: 1500/0.05 = 30,000 h = 1250 days > 3 years

 

[DM51]

Re: There goes 30 microamps, down the drain...

Sorry, I should have posted this here instead of LED forum...

Correct. However, having realised your mistake, you should have asked a moderator to move it, instead of cross-posting it in contravention of Rule 9.

I have merged the 2 threads.

 

[ltiu]

Re: There goes 30 microamps, down the drain...

If using the max drain of 90 uA and a typical CR123 at 1500 mA.

1,500,000 uA / 90 uA = 16,667 hours, about 1.9 years, at least.

You did say the battery is partially used and you left it inside for a few months. So it does make sense if the CR123 is dead.

 

[Lite_me]

Re: There goes 30 microamps, down the drain...

This must be the reason why when I pulled my 24/7 out of the map-pocket in my car door the other day after about 2yrs to check it out, it was dead! :mecry:

 

[Turbo DV8]

Re: There goes 30 microamps, down the drain...

This must be the reason why when I pulled my 24/7 out of the map-pocket in my car door the other day after about 2yrs to check it out, it was dead! :mecry:

Depends on if this is "normal" for this light, meaning , do they all do it? I don't know what is causing the drain. If you put the switch between two modes, it goes into the locator beacon mode, but otherwise I would think that off should be off. I was ready to send mine back, but if others are doing the same thing, this might be "normal," albeit not "acceptable."

Anybody have a DVM that'll do microamps and want to check for drain from theirs when it is "off?"

 

[yellow]

is that a mechanical switch, or an "electical" one (means: a button to touch, then some driver gets to work)

any electrical switch drains current and thus discharges the batt,
fight that with unscrewing the battery compartment bezel so far, that the circuit has no contact, only option in long term storage.

 

[Turbo DV8]

is that a mechanical switch, or an "electical" one (means: a button to touch, then some driver gets to work).

Not sure. You rotate the head to several click-stops to get the modes. If you rotate the head to a position between any of the clicks, it enters locator beacon mode, so maybe the switch is electrical even though there are clicks.

 

[ltiu]

Re: There goes 30 microamps, down the drain...

Depends on if this is "normal" for this light, meaning , do they all do it? I don't know what is causing the drain. If you put the switch between two modes, it goes into the locator beacon mode, but otherwise I would think that off should be off. I was ready to send mine back, but if others are doing the same thing, this might be "normal," albeit not "acceptable."

Anybody have a DVM that'll do microamps and want to check for drain from theirs when it is "off?"

I got a DVM that can go down to 1 uA.

I have been using this to find things.

I found out that my walkman radio draws 50 uA when "off", to keep the internal clock running and the station presets in volatile memory.

 

[Lite_me]

Re: There goes 30 microamps, down the drain...

Depends on if this is "normal" for this light, meaning , do they all do it? I don't know what is causing the drain. If you put the switch between two modes, it goes into the locator beacon mode, but otherwise I would think that off should be off. I was ready to send mine back, but if others are doing the same thing, this might be "normal," albeit not "acceptable."

Anybody have a DVM that'll do microamps and want to check for drain from theirs when it is "off?"

I posted above that my 24/7 was dead after about 2yrs. stored in my car.

I tested for current draw on mine, and it draws the same whether set to the locater beacon, or when Off.

Draw is about .03-04mA either way.

So mine has parasitic draw. Not sure if they all do. We'd need more input. That explains why it was dead after a few yrs. in storage.

I'll now put a piece of tape over the + contact and remember to remove it when needed. I haven't had to use it yet, in and emergency anyway, so it won't be that much of an inconvenience. :ironic:

 

[Turbo DV8]

Re: There goes 30 microamps, down the drain...

I posted above that my 24/7 was dead after about 2yrs. stored in my car. Draw is about .03-04mA either way. So mine has parasitic draw. Not sure if they all do.

Then I am thinking not much point in returning it to Inova. I will email them and ask if this is normal. Too bad one cannot easily lock out the cap by unscrewing it a few turns. I probably just never noticed this before because I never stored the light with the cell in it. With an name like 24/7 and being marketed as an emergency light using long shelf-life lithium cells, one would think that it wouldn't be designed to be dead when you finally reach for it and need it!:thumbsdow

 

[greenLED]

Re: There goes 30 microamps, down the drain...

:thinking: I've kept a 24/7 for years in my car and have never noticed the battery draining by itself. I let my son play with the light often, and I've only remember changing the battery once.

You know, maybe there is a problem with the "locator" setting? That's the only way I can think of to get self-discharge with time.

In any case, it's worthwhile checking with Inova.

 

[Lite_me]

Re: There goes 30 microamps, down the drain...

You know, maybe there is a problem with the "locator" setting? That's the only way I can think of to get self-discharge with time.

Could be... but the locator beacon doesn't flash when mine is in the Off position. :thinking: I made sure.

 

[PeLu]

Re: There goes 30 microamps, down the drain...

.... map-pocket in my car door the other day after about 2yrs to check it out, it was dead! (

I have observed that this currents can be highly depending on temperature. So maybe in a hot car, it could be much higher.
Warm the lamp to maybe 50° C and check again. (Also self discharge is much higher then).

 

[1 what]

Just had a look at one of my 24/7's...Same low uA drain. Mine are kept in cars in the hot sun but I've never changed the batteries. Might pull them out for a "test" each few months. Very interesting.

 

[Turbo DV8]

Re: There goes 30 microamps, down the drain...

I have observed that this currents can be highly depending on temperature. So maybe in a hot car, it could be much higher.
Warm the lamp to maybe 50° C and check again. (Also self discharge is much higher then).

Mine was just sitting in the house. Inova emailed me today and said my question has been forwarded to their engineering department. From the reports here so far, though, it seems this may turn out to be "normal" for this light. Which makes the name 24/7 rather oxymoronic, given the light operates on long shelf-life lithium cells, has modes such as "Signal Strobe," "S.O.S. Signal," "3 Color Distress Strobe," and "2 Color Emergency Beacon!" Even the name of the light, "24/7," implies readiness at all times for an emergency. You can't even easily lock out the tail cap, for Pete's sake! What a dud. The brochure states, "Intelligence is evident in all aspects of design..." I beg to disagree.

 

[roadie]

unless one is using a flashlight often like daily or weekly.

remove the batteries. while in storage.