...extremely efficient...

Is that true, once you factor in leakage? They're much more efficient than a battery if long leakage times are not involved, but they are in this application.

 

And only about 500 F @5V

 

What about using a super capacitor bank? No charging IC's to deal with, extremely efficient, no memory effects, and long life. I highly doubt anyone would get 5 years off a solar array on any sort of battery chemistry.

I don't know, I still think that Deep cycle batteries are going to whoop the super capacitors buttocks cost-wise.

 

I don't know, I still think that Deep cycle batteries are going to whoop the super capacitors buttocks cost-wise.

+1
With proper charge management, 5 years shouldn't be a problem. I've had car batteries last longer, and they suffer mechanical and thermal stress.

 

Battery Charging IC: BQ24400 ( LED Driver IC: TPS61042 On...esign and test one both ways to see who wins.

 

I mentioned the capacitors to our "battery guy" and he's going look into it more. I appreciate all the helpful information. I just got back from traveling for the last 5 days so I won't have anything new to post to keep you guys updated for a little while until I do something, but keep the suggestions coming as long as you have them. I appreciate it!

 

i appreciate your work..
i think input:5V/800mA, Output:5V/500mA,
battery capacity, 2400mAh that should me perfect..

I appreciate the comment, but the decisions for this sort of project needs thorough research so just posting numbers like that aren't super helpful.

Can you explain how you arrived at these values?

 

Is that true, once you factor in leakage? They're much more efficient than a battery if long leakage times are not involved, but they are in this application.

I was skeptical that caps are a good option. I still question the capacity per dollar. But I happened to leave a big electrolytic charged to about 90V last night and found it at 75V this morning. I guess that's a lot better than I expected. Storing a charge for a few hours overnight is doable. Still, batteries are better at delivering their power at a near-constant voltage, and can store so much more in less space for less money.

 

I once set up a spread sheet comparing the different advantages of the energy storage device and included energy density, weight, foot print in CC, cycle life, and price per Oz. per CC, per cycle, etc. Now a days you would add in the "green" factor, but energy density was clear, for my application.

 

I was skeptical that caps are a good option. I still question the capacity per dollar. But I happened to leave a big electrolytic charged to about 90V last night and found it at 75V this morning. I guess that's a lot better than I expected. Storing a charge for a few hours overnight is doable. Still, batteries are better at delivering their power at a near-constant voltage, and can store so much more in less space for less money.

Batteries are the most likely route for our application, but we do need to have a few different prototype ideas in order to validate the one we chose so it's work looking into. Plus you never know what you might find.

I know that a lot of the things I want to be done are doable with a microcontroller, but if I can stay away from it, it might be beneficial and cheaper. Not to mention it will cut on development time by eliminating a lot of programming.

So in order to aid in this, does anyone know of a standalone (or combination) of ICs that can turn off/on a circuit through some sort of wake up signal. In my case it would be a certain voltage coming from the solar cells and when that voltage reaches a certain threshhold it would "wake up" the controller/charge circuit to charge the battery.

I just started my search, but if someone already knows that's even better.

Thanks.