Emergency Lights

[RNeumann]

If I'm understanding this correctly the lights have shore power. When the shore power is lost the battery kicks in and the lights turn on. If that is correct my assumption is the "light" has an internal charger that isn't shutting off. The batteries are getting overcharged and ruined in short order. I also don't know what battery technology you are using- I'm assuming you are aware that some batteries get a memory which shortens the life as well.
If I'm not understanding this please ignore me.....my wife has to most of the time!

 

[k0ua]

If I'm understanding this correctly the lights have shore power. When the shore power is lost the battery kicks in and the lights turn on. If that is correct my assumption is the "light" has an internal charger that isn't shutting off. The batteries are getting overcharged and ruined in short order. I also don't know what battery technology you are using- I'm assuming you are aware that some batteries get a memory which shortens the life as well.
If I'm not understanding this please ignore me.....my wife has to most of the time!

No, these are valid questions and concerns. I too am puzzled as to the exact battery chemistry and voltages in these lights. Although the original poster is not really interested in repairing these devices and just wants some recommendations for new units, the tech in me wants to know why they don't work.

 

[Gem99ultra]

If I'm understanding this correctly the lights have shore power. When the shore power is lost the battery kicks in and the lights turn on. If that is correct my assumption is the "light" has an internal charger that isn't shutting off. The batteries are getting overcharged and ruined in short order. I also don't know what battery technology you are using- I'm assuming you are aware that some batteries get a memory which shortens the life as well.
If I'm not understanding this please ignore me.....my wife has to most of the time!

I also wondered if perhaps the units were overcharging the batteries. I could go along with the 7.6V in the unit that had been sitting idle for 6 months. Actually, I was surprised that it was even close to that high. But for the battery in the unit that had just failed to be 8.6V... doesn't make sense to me. I sorta sounds like the voltage regulator in the light fixture is allowing the batteries to overcharge, killing a cell.

One other factor that is probably important, I've checked the voltage inside the house and find its constant at 122V - 124V. We do have a power company furnished 'whole house surge protector system', so I doubt that an electrical surge has done damage to the fixtures.

Just for additional info, the batteries are:
S65 6-VOLT 5 ah Rechargeable Battery Pack; Big Beam Emergency Systems, Inc. -Crystal Lake, IL)
(Identical to the batteries that came with the new fixtures.)

Perhaps my problem isn't the fixture at all, but poor grade batteries? I don't suppose there are lithium batteries available yet?

 

[k0ua]

I don't suppose there are lithium batteries available yet?

Sure there are, BUT your charger circuitry (which is already suspect) for properly charging your lead acid gels cells is not correct nor safe to use for the Lithium ion batteries. This could easily result in a fire.

 

[k0ua]

The 8.6 volts is too high even for the bulk charge of that battery by at least 1 volt. If your meter is accurate, this may be the problem. You charging circuitry has "cooked" the batteries to death. A fully charged 6 volt gel cell might be 6.7 or so volts. Bult charge maybe 7.3 volts from the charger. Float charge should be somewhat less. I am leaning now towards the design of the charging circuit in the lamps is suspect.

 

[Mendonsy]

I did a quick search yesterday and found that some of the emergency lights are using 6 volt sealed lead calcium batteries. I have no idea what the appropriate specs are for a lead calcium battery.

 

[Larry Caldwell]

I did a quick search yesterday and found that some of the emergency lights are using 6 volt sealed lead calcium batteries. I have no idea what the appropriate specs are for a lead calcium battery.

There are sealed lead gel cells and sealed nickel-cadmium batteries. I don't think there is such a thing as a lead-cadmium battery. Ni-Cd batteries are 1.2 volts and they self-discharge pretty rapidly. They also have to be regularly fully discharged or they develop a "memory" fault that shortens the discharge wattage. The short service life sounds like a Ni-Cd pack that has developed a memory fault.

 

[RNeumann]

Ni-cad would be about the worst choice for this application. As stated they had big issues with memory which why they fell out of vogue. Hard to beat lead acid and lithium.

If it was me and I needed emergency lighting at my home I would wire all the lights into a single circuit and build an inline battery backup that came off near the panel. If that's how it was wired I'd be tempted to go that route.

It just seems these these devices leave a lot to be desired. I am on the annual test inspection side of these. I can tell you I have never done anything other than push the test button for a few seconds to verify it came on. No long term test at all. If you absolutely needed this route I'd talk to hospital maint staff (someone who actually uses/relies and tests these on a regular basis) of call a big reputable manufacture like Lithonia to see what they offer. I'm guessing they make models that pass code and models that actually provide a usable lifespan.

 

[Gem99ultra]

Awesome comments! I think you guys have hit the nail on the head regarding the problem. One of two things - either the charging unit is bad or they're crappy batteries.

I'm already thinking that the batteries aren't up to snuff. Mine are 5AH batteries. That'll be the first thing that I do - replace the batteries. After getting those charged up and installed, I'll give them a test run.

If that fails, I'll once again replace the fixtures. The cost of either solution isn't outrageous, but it's a lot more effort to replace 6 fixtures than 6 batteries since the fixtures are hard wired and mounted very high.

Some rooms in this old farm house are pitch black when the power goes out, so I have no alternative but to get something that works when needed. And out here in the sticks, that's pretty often :-(

One other afterthought, should I go with AGM batteries or just any lead acid type?

 

[Mendonsy]

These are the batteries that I found. I have not seen this type of battery used for anything other than emergency lights.
6-Volt-Lead-Calcium-Battery