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Oh wow I see now, wasn't even thinking glider. Can't miss that in the dark.

 

Some how I missed part about " always on" with full battery, guess we could go back to post # 10 & just reverse comparator pins 5 & 6.
The TL431 could also be used for V ref.

 

Well i will let me dad see these circuits he might be able to figure them out! (The only way i could figure them out is with a picture of a breadboard or specific parts and exact instructions but he should be able to figure them out!)

 

I do have some 555 chips and some other stuff i have salvaged from tons of electronics people like to throw away. So i might have some of these parts and pieces laying in my parts drawer.

 

Almost last question: Is the blink negative, dark space, or positive, light pulse? Seems that if light is always on, then a blink would be a short dark space, maybe a little longer, .5 s, than if it were a short on, 200ms??

 

The LED's are always on so blink would need to be a dark leds off blink. I assume that's what you were asking.

 

I think this time it is all here. Changed V ref. to a LM336-2.5V because I had one, but many other forms can be used from 1N4148, LED, zener diode, or synthasized zener.
If battery is above 11.1V U1-A-1, pin 1, will be low, holding U4 at reset, pin 3 low, FET on, LEDs lit.
Battery below 11.1 V, U1-A-1 willgo high, enabling 555 to oscillatte. C1 charges thru D1 & R9, 68k, giving a .25 sec. LED off time. When C1 charses to about 8V, U4-7 goes low discharging C1 thru R8, 1M, down to about 4V in 3.5 sec. LED's on.
As battery falls further, below 10.5V, U1-B-7 goes high, turning on 4066, digital/ analog switch- pins 1 & 2 shorted. Now R8 & R5 are in parallel giving LED's an on time of .8 sec, off time still .25 sec.

Possible option with 4066, is to reverse blink, 200msec on & 800 msec off to conserve remaining battery charge.

 

Do you have a solderless breadboard, easy way to test a circuit.
R1 & R3 are pots, multi-turn are better, can be left in or measured & substitute fixed values.
What part of the world are you in? I have all of the parts on breadboard available at cost if you are in US.

 

In post 27 the 10K pullup R from U1-B-7 to + 12V is missing.
It seems natural that when battery is low that we would conserve battery power, so added the option using 2 more sections of the 4066 to switch the blink pattern. On low V , 10.5V, LED on time pulse is shortened to 225 ms & off time 1 sec.??
U3-C-8, 4066, goes to +12V, did not get inked and was erased.

 

Sorry been super busy the last few days havent had a chance to log in and check this out. I do not have a breadboard although i could purchase one to test this out. Or i could purchase it from you depending on the price as you say you have it and i live in the us (south carolina).

 

Check all of the options & timing. If going with LM393, LM336, 4066,555,& IRF9540 on a light weight board, prob. dead bug style, postage paid for US $ 35.

 

Or if you just want basic parts, how about $6. PP?