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[everydayflyer]

I have one Door / Window unit in an aluminum out building about 70 feet from the console. With door closed and switch closed(checked with a meter) the console LED shows open circuit(zone). If door is opened and closed the console chimes as normal (Run 2) but if you try to arm  the system is shows open..  If I take the console closer to this building it works fine.  I guess it is a range issue, signal strong enough to work in chime mode but to weak to arm,(alarm mode).

Would adding length to the switch leads help. I assume the switch leads are used as the antenna.

Perhaps I have a voltage issue. I have rechargeable NiMH cells in the transmitters and this means nominal 2.6 volts instead of nominal 3.2 volts.  I know some RF transmitters operate at reduced power on lower voltage but have no idea how voltage sensitive these are.

[HA Dave]

I assume the switch leads are used as the antenna.

Perhaps I have a voltage issue. I have rechargeable NiMH cells in the transmitters and this means nominal 2.6 volts instead of nominal 3.2 volts. 

You know what happens when we assume! The antenna is internal to the DS10A. There is a passive reflector (I think its called) antenna mod... that involves merely gluing on a length of coat hanger or wire to one side of the unit. A search will provide the info.

However... since winter is over... you could run a length of 2-wire, wire back to the house. Then mount the DS10A in the house.. and the magnetic reed switch in the shed.

The NiMH battery's not only come to the job slightly low on power.... they tire-out really quick too. I think you'll be much happier with old fashioned alkaline's.

[dbemowsk]

The NiMH battery's not only come to the job slightly low on power.... they tire-out really quick too. I think you'll be much happier with old fashioned alkaline's.

Dave is correct.  Typically rechargeable batteries in the range of AAA to D size state an output of 1.2 volts whereas an alkaline battery states 1.5 volts.  Because of this lower voltage the device is naturally going to drain them faster.  When purchasing your rechargeable batteries, pick the batteries with the highest mAh rating you can find.  The mAh rating states how much power the battery can supply for a period of time.  For instance, a set of AA batteries rated at 2800 mAh means that the batteries can supply 2800 mili-amps or 2.8 amps for a period of one hour.  If you have a device that draws 700 mA, the battery should be able to run the device for 4 hours (2800/700 = 4).  Using this formula you can approximate how long the device will last on a charge by looking at how much current draw the specs say the device draws.

The only downside to Alkaline batteries is that they are disposable.  Once they die, you need to replace them with a new set which over time can get expensive.  With rechargeables, if you keep an extra set charged at all times, you can quickly swap them out and put the others back on the charger.  You may have to change them out more often, but I think you would save money on them over the long haul.

[HA Dave]

The NiMH battery's not only come to the job slightly low on power.... they tire-out really quick too. I think you'll be much happier with old fashioned alkaline's.

...Typically rechargeable batteries in the range of AAA to D size state an output of 1.2 volts whereas an alkaline battery states 1.5 volts.  Because of this lower voltage the device is naturally going to drain them faster. 

Actually I shouldn't have been so lazy. There are posts scattered thoughout the forum that discuss the BENIFITS... as well as the negatives of the rechargeable battery's. I just don't think the rechargeables are best used in these low and slow drain applications.

I use rechargeable battery's where I can myself.... and I also use a MESS of cheap battery's that spend a year or two in service... and then a lifetime in a landfill. I am sure that at some point in the future.. devices that use battery's will be better designed for the use of rechargeables. But for now... many applications just except throwaway battery's as viable power source.
 
I've extended the wires on my DS10As to the magnetic reed switches (as I suggested in my post). Getting all my DS10As in one area near the console. That can at least make range issues a thing of the past... and the frequent change-out of rechargeable battery's... less of a hassle.
 
P.S. dbemowsk I really like your new avatar!

[everydayflyer]

Thanks for the feed back. I am what most would refere to as a battery guru.
I have flown electric powered radio contrled model aircraft for years.

My rechargeable AAs are Sanyo Eneloops. These are extremely low self dscharge 2,000 mAh capacity which is in fact more capacity thanb most non rechargeable. I have two 4 cells smart chargers for these and many other chargers. My concern was reduced RF  with 2.6 versus 3.2.  The other 5 Door /Window units and two Motion units work fine with the Eneloops and one of the Door sensors is  30 feet further away from the console but not in a metal building. 

I will search for the passive antenna trick and perhaps will wire a 1 cell LiFePO4 battery to that unit (3.3V) which is 0.1V more than two fresh  alkies.

Charles

[HA Dave]

This has been mentioned here before... I think Puck has used a wall-wart solution.. at least with some "eye" sensors if not the DS10A's.... if my memory serves me correctly.

I got to thinking about this (I've have a similar idea for another project in mind for sometime anyway) and decided if not now when. This is a perfect time to try a solar mod. I picked up a little solar cell lawn light... designed for a deck or fence I guess... at big lots today. And will see what I can, or CAN'T do with it and the rechargeable battery's that came with it.

I dug out a new "eye" sensor to use in the trial. Picture attached.

[everydayflyer]

Solar charging would work no doubt. I have 8 solar powered walk way lights and they use two Nicads, Well they came with really cheap 600 mAh Nicads and I replaced them with fairly cheap 1700 NiMH cells which have done great for well over a year.

I have two 4 cells smart chargers fro AAs and AAAs. These charge each cell seerately and provide mAh in  (out if doing a discharge or cycle testing). I can charge the Eneloops at 1 amp. in under two hours and they will last well over 500 cycles. Charging them at 2 amps. cut thier life to 200 to 250 cycles and charging at 500 mA  (four hours)  perhaps 700 plus cycles. To me the 1 amp. 2 hour charge is best compromise. 500 cycles is allmost 10 years if charged weekly. Before they wear out something better will come along. My three year old ones are still as new and two of them get charged every fews day as I have an everyday carry  high performance LED flashlight that I use constantly.


I have my console connected to a UPS unit now but I have read this at times interferes with the Lamp control  units,which I have ordered. If this is the case I will use a 3 cell LiFePO4 battery for the console backup which should give me 60 hours or more backup and this battery I can recharge in 15 minutes. I will aslo use one of these to power my external siren (horn) which is a commerical one ,same as used by Brinks Security..

[dbemowsk]

Not to jump too far off topic for the thread...  Our dollar store here just had a boat load of small single LED solar yard lights for a buck a piece.  I bought about 40 of them.  They have one AAA Nicad in them and they last forever on a charge.  A few of them I bought I haven't put in place yet so they have been sitting on my kitchen counter solar side down for going on 48 hours now and the LEDs in them are still going strong.  If I used 2 of the small solar cells from those to mod an eagle eye, I think they'd work good.

P.S.  Glad you like the avatar Dave

[HA Dave]

....... If I used 2 of the small solar cells from those to mod an eagle eye, I think they'd work good.

That's what I am thinking as well. I selected the device I bought because it uses 2 cells (or so it says). I took the light out of its box in the store.. but it required a screwdriver to get to the battery's.

[HA Dave]

OK... a proof of concept. I know it works. See image below.

I was just told... that it isn't easy to spot the RF waves coming from the MS14A (turning on my office lights).. but it works.

[HA Dave]

I finished the Solar Powered Motion Sensor... and posted it in user modified devices

[Charles Sullivan]

One possible problem with using rechargeable  batteries in a DS10A Door/Window sensor:  If the total voltage of the two batteries is less than about 2.5 Volts the sensor will set a low-battery flag in its transmissions.  This would always be the case for rechargeables with a nominal voltage of 1.2 Volts each.

I don't own an X10 Security Console and have no idea what it does when it receives signals with the low-battery flag set.

[HA Dave]

I don't own an X10 Security Console and have no idea what it does when it receives signals with the low-battery flag set.

THX. I will have to test that.

[everydayflyer]

Sanyo Eneloops under a constant current 250mA discharge. Even under this load they hold over 1.25 per cell for hours.

Added 4-21-2010 .
There seems to be a fair amount of interest in te 250mAh rate discharge graph I posted. Bear in mind that a good non rechargeable AA is only aprox. 2000 mAh  and since the normal life in an X-10 DS10A sensor is a year which is 8760 hours  the average discharge rate(load) is therefore less than  0.228 mA. or 5.5 mAh per day. 
One hour on the graph equals aprox. 45 days plus, Also consider that as the load rate is decreased the voltage under load increases.

To help make this a little clearer perhaps and as I have never done a lower discharge rate test I am now going to conduct a 100 mA(0.1A) CC discharge using two Eneloop AAs in series. These were last charged several days ago and at start of test were just over 2.6 volts for the pair.

I will provide updates latter.


Checked voltage of sanyo Eneloops in my Shop Door Sensor( (DS10A) and after 7 days they read 2.62 volts and there is a fair amount of traffic on that door.
-----------------------------------------------------------------------------

Here is a link to Energizer factory performance data

http://data.energizer.com/PDFs/E91.pdf

On page 2 note that at 250 mA  at 21C the cell crossed the 1.2V point in four hours while my Eneloop graph at same 250 mA load  still had 8 cells at 9.84 ( 1.23 per cell average)? after 5 hours.  So much for thier (Energizer's) claim to  great performance in high drain applications.


The two Enellops at 100 mA drain (current on going test) after 5-1/2 hours (550 mAh ) are still at 2.55 volts.

8 hours  (800 mAh ) /  2.53 volts this is likely  5 to 6 months perhaps more of service life.

12 hours 1,200 mAh and 2.49 volts under load / 2.52 no load.

Attached graphs links below.

How two use A123 cell  in DS10A (Door / Window Sensor)posted here

http://www.rcgroups.com/forums/showpost.php?p=14916113&postcount=1

Worth a look IMO. 15 hours at 100 mA discharge rate  and cell was above 3.2 volts.
 

Note to moderators. The above is a Hot Link but RC Groups has no problems with them and I am a long time / active member there.



I wonder if there would be any interest in a rechargable battery Thread?

[everydayflyer]

Post #1 outlines the problem I was having.

I tried the passive antenna mod. and it seemed to help.
I used a LiFePO4 battery  (3.2volts) and it seemed to help.

Bottom line is however every 3 days or so the aluminum outbuilding's Door / Window sensor would show open on the Console even though it still chimed each time door was opened and If I set the alarm using the Bypass the alarm armed and the door being opened triggered the alarm.

I still do not understand how it can indicate open,act open when trying to arm but in fact arm and work even with LED blinking as an indication of being bypassed.

I got tired of this foolishness and ran the switch leads from the outbuilding to my shop which is only 30 from it. The shop is in fact 30 feet further from the Console but it has never failed to work perfectly but then the shop is not aluminum and there is not a steel carport blocking the RF path.


Update:4-29-10  It worked for a day then same old same old. I gave up and replaced the Sensor and will see how it goes now. One day and all is well.