Battery protection automatic cut-off

[ermsk8er]

it would need about 100ma. to function

Thanks for answering my questions, sir..
Can i use this solar-charger.jpg as my protector? While my panels rating 12v @ 200ma.
If so, could the battery remain on charging while i load it? (the load connected to the battery). Thanks!

[Sunny Solar]

Your charge controller circuit in post#31 would need a minimum of 12v and 6w actual output. So it would need to be rated at about 12v and 10w. As there are losses through the LM317 and the resistor and zenner diode.
Also you cant use my voltage switch powered off one supply to control another supply. And that goes for any voltage switch.
You are going to find it very difficult to get a voltage switch to disconnect a 4.8v battery that has dropped below that voltage as most ICs will need at least 5 v to operate.. and its hard to find a 5v relay that will have enough current carrying ability to disconnect the load from the battery.

[ermsk8er]

Your charge controller circuit in post#31 would need a minimum of 12v and 6w actual output. So it would need to be rated at about 12v and 10w. As there are losses through the LM317 and the resistor and zenner diode.
Also you cant use my voltage switch powered off one supply to control another supply. And that goes for any voltage switch.
You are going to find it very difficult to get a voltage switch to disconnect a 4.8v battery that has dropped below that voltage as most ICs will need at least 5 v to operate.. and its hard to find a 5v relay that will have enough current carrying ability to disconnect the load from the battery.

tsk tsk tsk...hhmm.. where can i find a controller circuit to this (solar panel 12v @200ma my battery is 6v @ 4.5AH)? please....thanks! 12v battery is to heavy for me..

[Sunny Solar]

solar panel 12v @200ma . Have you ever measured its output ? or is that its rated specs? If its its rated specs its only likely to put out 100ma. About half the min you would need to keep that 4.5ahr x6v battery charged.Assuming its almost never discharged more than 1ahr.

[ermsk8er]

solar panel 12v @200ma . Have you ever measured its output ? or is that its rated specs? If its its rated specs its only likely to put out 100ma. About half the min you would need to keep that 4.5ahr x6v battery charged.Assuming its almost never discharged more than 1ahr.

yes sir it is its rated specs. Is this kind of set up needing a protection to the battery? if so, do you have a circuit controller that will suit to my set up.. i need it badly, it bothers me to much..

[Sunny Solar]

There is no nice way to tell you this.. Your 12v 200ma panel is just about useless for anything.. It could power a LED in the midday sun but not much else.. It has just about enough output to recharge a "D" size rechargable battery..

It certainly would not overcharge a 6v battery . Just connect it to the battery ,you dont need a charge controller or there be no output from the controller...

I dont know what you are powering from that battery but it wont power much either,or it will have a short unhappy life..
its useful output is 6w for 2 hrs.Before it needs to be recharged.

[ermsk8er]

There is no nice way to tell you this.. Your 12v 200ma panel is just about useless for anything.. It could power a LED in the midday sun but not much else.. It has just about enough output to recharge a "D" size rechargable battery..

It certainly would not overcharge a 6v battery . Just connect it to the battery ,you dont need a charge controller or there be no output from the controller...

I dont know what you are powering from that battery but it wont power much either,or it will have a short unhappy life..
its useful output is 6w for 2 hrs.Before it needs to be recharged.

2 hrs? its ok for my small project.. so i connect the battery directly to the panel. Hhmm, what would be the charge time for that, sir?

[Naptown]

There is no nice way to tell you this.. Your 12v 200ma panel is just about useless for anything.. It could power a LED in the midday sun but not much else.. It has just about enough output to recharge a "D" size rechargable battery..

It certainly would not overcharge a 6v battery . Just connect it to the battery ,you dont need a charge controller or there be no output from the controller...

I dont know what you are powering from that battery but it wont power much either,or it will have a short unhappy life..
its useful output is 6w for 2 hrs.Before it needs to be recharged.

You will need to at least install a blocking diode to prevent the battery from draining into the panel if they stay connected at night or during non sunny hours.

[Sunny Solar]

Most panels have a blocking diode installed .But if yours does not then a diode needs to be inserted into the + wire. a 1n4004 would be ok ,cost about 10cents.
Recharge time would be about 4 days for that discharge..

[ermsk8er]

Most panels have a blocking diode installed .But if yours does not then a diode needs to be inserted into the + wire. a 1n4004 would be ok ,cost about 10cents.
Recharge time would be about 4 days for that discharge..

thank you very much, sir solar! Last question. Can i connect a load to battery while charging? The load is 12v @ 0.30A. Thanks again..

@naptown
thanks, sir!

[Sunny Solar]

yes of course you can connect a load to the battery while its charging. its even better to use power while the battery is recharging as it reduces the load on the battery.. Just like your motor vehicle charges the battery while you driving and using lights etc..

[ermsk8er]

yes of course you can connect a load to the battery while its charging. its even better to use power while the battery is recharging as it reduces the load on the battery.. Just like your motor vehicle charges the battery while you driving and using lights etc..

Thank you so much sir.. God bless! Take care!

[choyak]

About 9 months ago, I made this little thing that has a bidirectional relay, and tweakables, with op-amps used as comparators. I tweaked it to switch off at 24.8 and on at 26.1 so as the battery drained, the relay clicked off. It worked pretty good, however now, my MPPT charger has a relay to set the voltages, (and it is better)


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