OK. Here we go again.

So, i've made a Solar AP Power controller.

Not *only* does it Charge Car Batteries Properly from Solar Panels, using a variant of MPPT and other related tecnologies, it is biased towards keeping your AP alive, rather than saving 50 euros of battery from maybe 1 week of extra life.

It uses 2x 20W Solar Panels to avoid the need for any heliostatic mechanism.

+1

Schematic :

Parts List :-

IC1 7505 +5v linear regulator
IC2 Microchip 12F675

T1 (says Q1 on schematic) IRF9540 HexFET (P-Type)
T2 BC109 or any small signal transistor
T3 L2203N HexFET (N-type)

All Diodes SB650 or similar schottky type (i chose 3A types)

R1,R2,R1 1k
R3,R6 47k
R4,R5 4k7
R7 10k

C1 10uf 16v
C2 47uF 25v
C3,C4 100nf
C5 10uf 63v - needs to be rated at least 25v to stop it exploding on a good day.

The HexFETs and the BC109 are just the types i already had. Other similar types will work just as well.

Hex to flash into the PIC chip attached.

The forum would not allow me to upload the .HEX file, so i changed it to .TXT

I forgot to say.

If you short pin 4 of the PIC to 0v, then it hard-reboots your AP every 8 hours (approx)

This option is for very very remote locations where anything can happen, and does.

The Battery Charging strategy goes like this :-

If the battery is > 13.8 volts, it leaves it alone, and doesn't charge it at all.
If < 12.5 volts, it trickle charges it (150mA) back up to 13.8 volts.
If < 12 volts, it fast charges at up to 1.5A until the battery is 13.8v again.

OF COURSE, it will *not* be charging the battery at all unless there is enoug Solar Power to be running the AP, and extra is left over to charge the battery.

Better to let the battery die than the AP.

So, when the AP is running on Solar Power, (i.e. using nothing from the battery) *and* there is spare energy from the Solar Panels, the circuit charges the battery.

If there is enough power, and the battery is 'flat', as in below 12volts, the circuit will Bulk Charge the battery at about 1.5A, until the battery reaches it's Maximum charge level.

There are timers to limit how long this can happen, in case the battery cannot accept the charge.

If the battery is partly charged, i.e. above 12v, then it will get a Maintenence charge of about 150~200mA until it reaches the Full level.

If the Battery is above 12.5v then it is not charged at all, but is allowed to gradually reduce to the 12.5v level.

Maybe i have not got the trigger voltages right yet, but it seems to work pretty well.

If there are any Lead Acid Charging experts out there, sound off.

I would be good to rewrite this info to encyclopedic form to wiki. Maybe http://wiki.mikrotik.com/wiki/SolarTik

(snip) If the battery is > 13.5 volts, it leaves it alone, and doesn't charge it at all.
If < 12.5 volts, it trickle charges it (150mA) back up to 13.8 volts.
If < 12 volts, it fast charges at up to 1.5A until the battery is 13.8v again. (snip)

Good idea, but I don't think it is enough current on the trickle charge. A 433 with one radio will use more than 150ma. That means the battery would need to slowly discharge to < 12 volts before getting a full charge. That will shorten the battery life considerably.

FYI: Not *all* WISPs are cheap or mean. This charger is my current fav:
http://store.solar-electric.com/mosumpsochco.html

ADD: AND they are on special this week!! Thanks for drawing my attention there. I'm going to buy another now.

message removed

You'll find that the Morningstar doesn't try to shove lots of amps into a fully charged battery.

A "fully charged battery"?? Why would my charger shove lots of amps into a fully charged battery? But it does supply enough current to replace what has been used!!!

i like your design and think it would be way cheaper... i didnt price your parts list, but i assume its only about $30 of parts?

rs232 would be cool. it wouldnt be that hard since your using a pic already.

i have a dc-dc power supply that has an api over usb/serial. carnetix. its pretty slick.

would it be hard to allow a 120v AC charging source into your design? have it accept either a DC panel or a 120v wall outlet I have 2 odyssey 2150 batteries id like to use as power source for a handful of radios with 120v AC charging them. I'm not sure if charging them with a standard charge controller would ruin the batts (requires 14.8 voltage to charge them / 3 stage maybe).

I think it is a good idea! But I still don't understand this part:

The next phase is 'drift-down' where the battery voltage is allowed to drift down to a lower voltage ~12.5v. Then the 150mA phase 'tops' the battery back up to the upper limit, again with timers for safety.

If the charger supplies 150ma, and the router is using 300ma, the battery will slowly discharge. Or do you mean "load current + 150ma"?

ADD: I think an ethernet port would be perfect! But I also know PICs have easy RS232. I use Microchip and Rabbit embedded processors for my other projects.
http://www.rabbit.com/

Can you se D8 top-left-and side ?

That is *exactly* what that is for.

You do not need to use Solar Power for this design. You can use an ordinary PSU.

I tend to buy lots of IBM (or compatible) Laptop PSUs on Ebay for about 6 quid.
16v 4.5A.

Does the circuit shut down output when batt voltage <10.5V?

yes, the circuit/program turns the AP off if there is less than 10.5v available from anywhere.

I have looked at adding an Ethernet option, and it can be done, but at about $20 extra cost.

RS232 seems like the most sensible option.

If long cable runs are involved, then PoE-style powered RS485 migt work.

Any suggestions ?

i am a pompous tosser.

correction.

i *can* be a pompous tosser. dunt meant i'm always a ...

How come we are unable to decrease karma?

im sorry to see you delete those posts. if you wouldnt mind emailing me the parts list and schematic again i'd love to build one. i would rather build my own than spend $200 on a commercial one.

I'm sorry too. Maybe I wasn't planning on building one, but I thought it was a good idea, and mentioned that twice! My only concern was the trickle charge may not have been adequate.

The charger in the link I posted above is the top of the line for MorningStar. It uses Maximum Power Point Tracking (MPPT). It can produce more charging amps to the battery than the panels can produce alone. A standard charger is less than $70 with a great weatherproof case.

EDIT: I'll remove the reference to that remark. That was close enough to a good apology!

Pity.

I was following this with interest.

Rgds,
Mark.

OK.

I threw the dummy out cos i was pissed (English meaning) and annoyed.

Not Surfer Dude's fault at all.

I'll put the stuff back.

The common practice with these chargers is to cut off the charge current for a few milliseconds, then take a voltage reading of the battery to determine charge state. If that is what you are doing, then all is well!

Glad you put it back. I still think it is a good idea!

It turns the charging current off for about a second to read the battery voltage.

Milliseconds didn't work (tried it), cos the capacitors in the Buck circuit take a while to discharge.

How is this circuit better than this for $30:

http://www.streakwave.com/mmSWAVE1/Vide ... _Sheet.pdf

Tycon Power Systems solar controllers are 3 stage PWM type battery charging controllers controlled by an industrial CPU. The 5A controller is available in a 12V battery model. The 8A controller is available in an autodetect 12/24V model.
They have full electronic protections for short circuit, reverse current, overvoltage, overcharge and over discharge. They offer battery overdischarge protection by disconnecting the load when battery voltage reaches 11.1V (22V for 24V controller) and automatically reconnecting the load when battery voltage reaches 12.2V (24.2V for 24V controller).

Hi,

Since the schematic is not visible anymore I'm not sure about your design but the Tycon 5A model for sure removes power to the load if you remove the battery (eg for maintenance) even if power is being supplied at the input.

That is rather useless if one is just doing preventative maintenance.

Does this happen in your design? If not, I'm even more interested.

Rgds,
Mark.

How is this circuit better than this for $30

I dunno. Probably isn't much different as it's doing the same job i guess.

It is 'better' in that if you can suggest how SolarTik can be improved, then i can work out how to do it and post SolarTik v2.0.

One idea was to have a local or remote reboot input, so a GSM rebooter, 433Mhz keyfob, or just a Big Red Button could reboot the AP.

Stuff like that is easy, and would not cost any more to implement.

Te idea is to try to make an AP-focussed Solar Charger, not just a good battery charger.

removes power to the load if you remove the battery

This design would not disconnect power to the AP if you remove the battery, so long as there is enough Solar Power to run the AP.

Possible improvements :-

Reboot input for GSM rebooter, or Keyfob
Reboot push button
RS232 interface to report voltage etc
Ethernet interface & web page
LCD display & ability to set mid, hi, low voltages + charging profiles
Battery Alarm siren/flashing light

Suggestions welcome

Nice one Adrian. There are not many commercial products out there that address our needs.
will you be producing a PCB?

Thought I would take the opportunity to proffer our solution.
We are currently using a somewhat more expensive, but very simple solution, which relies on two basic principles.

1) It is safe to charge any (please don't trust me here, I know not what I say!) Lead acid battery indefinitely as long as the charge current is = or < 1% of the amp hour rating (20h rate) of the battery

2) Solar cells are virtually a constant current source, that is to say their short circuit current is a fixed value in almost any lighting condition.

We use 24V panels charging 12V batteries directly across the terminals (add a diode and a fuse in series for safety and good engineering).

The panels we use are rated at 180Watt, 24V. We measured the charging current when connected to a 12V lead acid battery in bright sunlight and found it was around 7 amps, in overcast conditions it was typically 4 Amps. The load of our nodes is around 1.5 amps @ 12V. Applying principle 1 above, we decided that 500AH of lead acid ( 5 X 110AH car batteries) could be floated (12V all in parallel) without any charge regulation.

The benefits of this solution are:
1) Simplicity & Reliability
2) Charging under most lighting conditions (the 24V panels easily make 12V, under low light conditions)
3) A large reserve of stored energy means the batteries only have a shallow discharge (ok for car starter batteries), copes easily with winter months, and we hope to have a long battery life.
4) Occasional slight overcharge (we understand this is good for Lead Acid batteries).

Draw backs:
A) Lots of expensive batteries
B) Big expensive solar panel
C) Batteries should be checked/topped up every 6 months.
D) No low voltage disconnect circuit. We have never needed one but this could be dangerous in the event of a battery failure, as gassing could occur (use in a well ventilated area)
E)No remote reboot facilities


We monitor charging and battery condition using SNMP graphed in Dude from the health voltage mon on a RB333.
The solution has been good for two years plus.

During late summer afternoons the voltage occasionally reach 14.9V for about an hour.
typical daytime voltage is between 13-14V, Night time 12-12.5 volts.

will you be producing a PCB?

When all of the sudden flood of Wishes are incorporated, i'll do a PCB design for it.

Currently that looks like Wednesday.

Probaly do a PCB and a Kit even.

Hi,

Maybe some way to monitor temperature?
Or a simple set of contact relays?



Rgds,
Mark.

+ relays

Temperature monitoring is a good idea.

You mean measure the battery temperature before Bulk Charging starts, and stop the charging if the battery temperature rises too much ?

Or to do you mean temperature/humidity/windspeed/rainfall monitoring as well ?

I'm not being too silly with that question, cos they can all be done.
Might as well make a *complete* device rather than just another charger.

+ relays

Relays for what ?

It would be really really good if Mikrotik dumped the MetaRouter thing and just put some (maybe script-accessible GPIO on their boards.

We could do all sorts of amazing things then, like provide internet *and* Fridge control.

digital inputs maybe

Nick Kett skyped me earlier and suggested that a 48v output would be ideal for the RB600s etc.

He's a bit shy, so i posted it for him.

I *think* his idea will only work with 24v battery arrangements.

So, 12v/24v battery auto-sensing is In.

Digital Input/Output or even Relays can work.

I just need to know what they will do, and can incorporate them.

come on guys n gals !

What do you want a super-duper AP power controller to do ?

Even if you think your idea is useful just once in a blue moon, it'd be very nice to have the solution already there and waiting.

So Far we got :-

Ordinary PSU option
Solar Panel Option
AP priority Proper Battery Charging (aka PWM etc)
Low-Voltage Cut-off (aka Load Sensing)
Industrial/Military Grade Processor (Look www.Microchip.com up)
MPPT - in so far as it can be applied to this requirement
8 Hour AP auto reboot option


Wishlist so far (that i understand) :-

12/24 battery auto sensing
48v output (only on 24v battery/PSU/Panel so far. I can only get 36 from a 12v battery today)
Temperature Sensor to compensate for Hot Batteries.
PoE RJ45 connector + the other one
LCD display
Charge parameter/profile adjustment via buttons
RS232 interface so it can report voltages etc to the MT
Big Red Button to press to reboot the AP
Remote Reboot Input (GSM rebooter, Keyfob transmitter etc)

Wishlist so far (that i do not understand) :-

Relay Inputs/Outputs
Radio Control


Wishlist so far (that i understand, but i think is going to add too much cost) :-

Ethernet socket and web interface
Motorised Heliostatic controller


C'mon throw them in there.

Ability to on/off POE remotely or on schedule.

Ability to on/off POE remotely or on schedule.

Are you drunk as often as i am ?

8 Hour AP auto reboot option
Big Red Button to press to reboot the AP
Remote Reboot Input (GSM rebooter, Keyfob transmitter etc)

Isn't that kind of what i said, you said ?

If you mean something else, please explain it in more words .

Ability to on/off POE remotely or on schedule.

Are you drunk as often as i am ?

8 Hour AP auto reboot option
Big Red Button to press to reboot the AP
Remote Reboot Input (GSM rebooter, Keyfob transmitter etc)

Isn't that kind of what i said, you said ?

If you mean something else, please explain it in more words .

I need more than one POE port each remotely controlled state (on/off) by ethernet (or serial/GSM). I think 8 hour auto reboot option is of little use as "reboot on schedule feature" as it cannot be controlled remotely.

Hope that clarifies few things. Of course it's up to you where you take this project and I'm looking forward to it.

You mean add a PoE Switch! Great idea. How many ports ?

Tricky part is how to control it.

You mean add a PoE Switch! Great idea. How many ports ?

Tricky part is how to control it.

I would prefer a set of darlington, 1.1A PTC, fused outputs. POE injectors can be easily added when needed.

HEXFETs are much better. They're the kind of Nirvana of the Darlington driver world.

By Control, i mean the mechanism by whch you turn the ports on and off, like what you do on the Mikrotik to make the power go on/off.

If you can live with 2 switched PoE ports, then i can already do that with the Ubiquiti Routerstation (about 40 euro board) with a nice Web interface.

The downside is the power required to run the UBNT RS.

Relay Inputs/Outputs

well example relay

on solar so if the solar pannel get stole relay opens and send output to mikrotik and mikrotik smses me pannel is gone

on there uses and put door switch on relay and when door is open mikrotik emails me door is open

and many more uses

If you are thinking of designing a pcb/kit how about integration for a GSM module.
Such as http://www.mikrovlny.cz/en/product/44 ... KIT_en.pdf
would add full out-of-band site alarms and re-boot facilities via SMS/GSM.
As an "add-on" PCB it could be linked-out if not required.
Maybe it would work as a "daughter board", or just use the same footprint for easy stacking.

So a full AP security system then ?

How about adding a camera and the ability to open a Door Release remotely ?

GSM ?

Hmmm. I did quite a lot of work with GSM modules a few years ago.
I expect that they're a lot cheaper now.

Excellent suggestion.

GSM option is In.

so whats all in now?

It seems that SolarTik has basically served to point out that there is no real need for a Solar Charger, because you can buy one for about $20~$30, and the parts & time to make one would be roughly the same.

However, it does seem that there isn't anything out there that sucessfully fits the needs of a Mikrotik Power controller, or AP site Manager, specifically :-

1. About 4x MT PoE ports with 12v, 24v or 48v PoE power options.

2. Programmable low-voltage shut off, with programmable re-tries in case the power comes back.

3. Scheduled rebooting.

4. Remote rebooting/power control either through a web or GSM interface.

5. Multiple Power source options (e.g. solar, wind, normal PSU, nuclear

6. Big red button so Client can reboot without a brain

7. Automatically report stuff, like voltage/alarm

8. Relay outputs to control things like a Door Release mechanism

9. Camera option to see who's there with automatic FTP of images to somewhere

10. Digital/Alarm-style Inputs to detect if somebody opened a door, broke a window, stole something etc.


Maybe i should start a new thread called TikGuardian.

I bought a $30 solar charger off Ebay and it arrived today.

It charges the battery a bit high - 2.5A, but it has all of the features of many others i have seen the specs of.

Low-voltage cut off
PPM charging
MPPT
Industrial Processor (Atmel in this case, not a Microchip one - lol)
etc etc.

It turned the AP off earlier, and there is still 11.98v in the battery.

The Battery will be fine, which i care not one bit about - this Proper Professional Solar Charger decided to Sacrificed the AP for the sake of the Battery.

They all do. Try and tell me it is not So, and post Proof.

This is *exactly* why SolarTik is better.

SolarTik is designed to do it's best for the battery,
but the AP Must Live - batteries are cheap, Downtime is Bad.

We use 24V panels charging 12V batteries directly across the terminals

That seems like a really bad idea to me.
Everything I ever read said that charging batteries at so much above their nominal voltage damages them seriously.

It seems that SolarTik has basically served to point out that there is no real need for a Solar Charger

That's right. Also, there are many different types of solar panels and batteries that require different chargers.
There is enough solar charge controllers on the market today, no need for you to waste your time making another one.

What we really indeed need is a power controller.

Well, this construction seams sensible, although there are a couple of tons of such circuits in fleabay. One thing they lack is 36 or 48 volt support. It can either be done by more batteries or smps upconverter - say, 24 to 48 volts.
A neccesary feature would be - "power lost" warning - ROS can easily manage that, by either monitoring serial port pins or the voltage - this way we know, when we have lost the power and when to start looking for car keys in case that it doesn't come back.
Most important, this solution should be inexpensive enough to stimulate small ISPs to use it, just like surge protection - noone will be happy to buy RJ45 surge suppressor for 100$ even if the routerboard costs >200$.
Another idea is NiMh controller - smaller batteries - smaller overall enclosure - good for switches and smaller routers.

smps upconverter - say, 24 to 48 volts.

LM2577-ADJ is perfect.

come on guys n gals !

What do you want a super-duper AP power controller to do ?

Even if you think your idea is useful just once in a blue moon, it'd be very nice to have the solution already there and waiting.

FM Radio Reciever with DTMF Decoder to flop the power when your AP locks up.

Jason

Nice one, probably.

what is a DTMF Decoder, and how would you like the unit to use it ?

(i could Google, but maybe you have a specific requirement)

Nice one, probably.

what is a DTMF Decoder, and how would you like the unit to use it ?

(i could Google, but maybe you have a specific requirement)

DTMF = the dial tones on the phone. "Press 1 to reboot AP1, Press 2 to Reboot AP2" and so on.

Nice one, probably.

what is a DTMF Decoder, and how would you like the unit to use it ?

(i could Google, but maybe you have a specific requirement)

Mainly I have a Ham Radio Repeater system that all of my sites can hear. Pass some touch tone commands and when the decoder at the ap hears that over the radio it will flop a relay and power cycle the ap.

you got a good (and cheap) DTMF decoder chip to recommend ?

Many years ago i saw the NE567, but i'm sure there's newer stuff.

I finally got a TCP/IP link over PPP on the mikrotik serial port from my PIC chip.

I can Ping it ! WooHoo !

(MT PPP is a bit arsey, like when it sends 7E - or not. Had to build a protocol analyser to find that out)

Anyway. Happy happy. Progress happens.

Web interface to follow, then the easy bits, like the Entire wishlist.

PowerTik is almost there.

nice cant wait

RS232 interface so it can report voltages etc to the MT

It's here: http://tandem.ck.ua/ups_mtm-eng.php

Hi guys,
Why don't use restlesspowerbox compact,
It has all Features you like to have and Power it from 24v batteries charged by Solar Panels?

http://www.restlesspowerbox.com/index.p ... &Itemid=16

Ks

that one looks good.

see this
http://cgi.ebay.com/10-Wired-Wireless-B ... 45f55bc5f3

Hi guys,
Why don't use restlesspowerbox compact,
It has all Features you like to have and Power it from 24v batteries charged by Solar Panels?

http://www.restlesspowerbox.com/index.p ... &Itemid=16

Ks

You got anywhere that has a price with it? And do you know what GSM Modems it can use?