12v solar charger

[whoknows]

I have a 12v solar charger designed to maintain a charged car battery(lead acid). I was wonder if it will charge all types(ni-cad, etc) 12v batteries?

also if I hook up 2 chargers in parallel, would 1 charger be canceled out because of the blocking diode in each of the charger or would they work together and produce more amps?

 

[audioguru]

A 12V solar panel produces a voltage higher than 12V with a low current which drops to the battery's voltage. Its max current is when the sun is extremely bright and depends on its size.
If it has a size large enough to charge a car battery then its excessive current can easily overcharge a Ni-Cad or Ni-MH battery. It can cause a Lithium battery to explode or catch on fire.

Two identical solar panels in parallel produce double the current of one. The blocking diodes will be forward biased during sunshine but prevent the battery from discharging into the solar panels at night.

 

[whoknows]

thanks for the info

Do you think it would be safe to charge a sealed lead acid 12v battery(UPS battery)?

 

[audioguru]

Your solar panel is probably designed to trickle-charge a car battery, not charge it after it is used. After it is used, your UPS battery is probably also much too big to be charged by a small solar panel.
Trickle charging makes up for the small amount of charge that is lost when a charged battery sits, not being used.

 

[HarveyH42]

I have 3 of these solar panels, work great keeping an unused car battery charged. They claim 12v @80mA, but even all 3 in parallel wasn't enough to charge a 12v 1.7AH sealed lead acid battery. One panel barely charges 8.4 volts worth of NiCd AAs...

 

[Nigel Goodwin]

I have 3 of these solar panels, work great keeping an unused car battery charged. They claim 12v @80mA, but even all 3 in parallel wasn't enough to charge a 12v 1.7AH sealed lead acid battery. One panel barely charges 8.4 volts worth of NiCd AAs...

Florida isn't sunny enough to reach their rated output

 

[whoknows]

well I used (1) 12v 120ma solar panel to run a 8v 50mw wireless camera. Now what I want to do is run 4 solar panels into a 317t reducing the voltage to 9v and trying to run 2 cameras during the day and 2 at night. Everything so far is working fine(during the day), I just need to find a way to charge a cell for night recording.

 

[tom muleady]

i HAVE EXTENSIVE time experimenting with solar chargers.I have a 1 kw inverter i bought at a ham radio swap plus two deep cycle batts.I built several charge controllers from designs in qst mag.Dont have the mths but from 1990-2004??I also bought 2 surplus panels no -
load apprx 18-20v with loads of 12-14vts at apprx 1.8 amps Then Ibought a New panel 65wtts .My inverter was a 24 vlt circuit so I put the panels in series to slow charge but,with my charge controllers I could charge any kind of battery ,by adjusting the time on and the current sensed the chargers would cycle on and off,called a hysterisis circuit,.I did this cause i was a caretaker on a indian reservation for about 17 yrs,no elec or telephone,so my needs became very focused even on cloudy days I could get 300-400 milliamps enough to run lights (12)small 12vt tv.So email me ,I would be happy to help you all I can.Iv'e since moved back to the city,gardena,calif,I still use my cells to charge my batterys that I use for my ham circuits and batts.I also know that You probly want more current to charge so lets see what we can do.
tom(leatherman)NE6AO
my other hobby

 

[whoknows]

Thanks for the Info everybody

This weekend I am going to charge 8 AA batteries in series. When the batteries are fully charged I will turn on the cameras and see if the solar panels can keep up with the demand. I will let you know my results in a week or so.

 

[raybo]

If you have a 12 VDC solar panel how do you ever expect to charge a lead acid battery 12 vdc car battery when fully charged is more the 13 -16 vdc with these solar panel even a 1000 in parallel the battery will never be fully charged. i sugest you put them some in series to charge the battery you might suceed. missconception that 12 v is allways 12 v on a car lead acid battery is false. my go to 17 volts when charged fully and drains exponantialy.
Finaly you need higher voltage then the battery and need current flow into them

 

[raybo]

histerisys is not time on and time off but is a dead band created to provide a means of controlling switching as opposed to continious switching without.

i HAVE EXTENSIVE time experimenting with solar chargers.I have a 1 kw inverter i bought at a ham radio swap plus two deep cycle batts.I built several charge controllers from designs in qst mag.Dont have the mths but from 1990-2004??I also bought 2 surplus panels no -
load apprx 18-20v with loads of 12-14vts at apprx 1.8 amps Then Ibought a New panel 65wtts .My inverter was a 24 vlt circuit so I put the panels in series to slow charge but,with my charge controllers I could charge any kind of battery ,by adjusting the time on and the current sensed the chargers would cycle on and off,called a hysterisis circuit,.I did this cause i was a caretaker on a indian reservation for about 17 yrs,no elec or telephone,so my needs became very focused even on cloudy days I could get 300-400 milliamps enough to run lights (12)small 12vt tv.So email me ,I would be happy to help you all I can.Iv'e since moved back to the city,gardena,calif,I still use my cells to charge my batterys that I use for my ham circuits and batts.I also know that You probly want more current to charge so lets see what we can do.
tom(leatherman)NE6AO
my other hobby

 

[HarveyH42]

If you have a 12 VDC solar panel how do you ever expect to charge a lead acid battery 12 vdc car battery when fully charged is more the 13 -16 vdc with these solar panel even a 1000 in parallel the battery will never be fully charged. i sugest you put them some in series to charge the battery you might suceed. missconception that 12 v is allways 12 v on a car lead acid battery is false. my go to 17 volts when charged fully and drains exponantialy.
Finaly you need higher voltage then the battery and need current flow into them

So, a 12v battery is never really 12 volts? But 12v solar panels always are? Gee, how could I be so stupid... Come on now, 12 volts is relative for both, and varies, it's expected. Would it have been more useful to just say 'battery' or 'solar panel'? It's just for reference....

 

[audioguru]

Simply measure the voltages.
My "12V" solar panel is 18V in full sun without a load and its voltage drops down to the battery's voltage when it charges the battery.

My old car battery was not sealed and I had to fill it with water occasionally. It measured 13.8V fully charged while still charging.
My new car battery is "maintenance free" and is sealed. It measures 14.4V fully charged while still charging.

 

[raybo]

you are rambling water is it that you are topping off. no wander your battery is weak. and close this a this thing is giving me a head hache

 

[tom muleady]

ok raybo your splitting hairs useing a comparator circuit,iam measuring sampling voltage all it does is turn a fet on and off which is a switch that allows the solar panels or sometimes my bench power supply on and off to not over charge the load this allows me to have alot of versitility options for what ever load i have.audioguru said it the way it is.

 

[raybo]

defenetly NO if I tell you to shut this off- then that on- is not the same as me saying shut this thing off tomorrow and turn it on day after tomorrow. i am not splitting hairs you guys are doing it but fighting each other i say this he say that. I THINK THIS SHOUL BE TO HELP THE ORIGINATOR NO TO GET YOU GUYS A LIFE.

 

[tom muleady]

ok ok what ever floats ur boat,I definitly meant no disrespect to you that terminology was used in the articles in fet solar charger qst mag.