So I came across this on EBay... and they are very local to me... but it sounds like a $100 experiment gone bad. The specs on this thing are waaaaaaay different than any other 12V solar panel that I've ever seen.Max V 15.03V?Amps at short circuit 7.92?Vmp... 11.97Could someone with more brain power than me check the specs on this and tell me it would charge a Trojan T-1275 without even the need for a charge controller? What about diodes and sucking juice out of the battery and back into the panel?Thoughts? Funky Spec'd 100 watt panel with huge amps.Do you run this with one of Mex's Voltage buck / boosters, then through a charge controller, so that there is enough V to charge a battery properly at bulk mode, 14.8V and give up a few amps in the process?Need help, guys, but in layman's terms, EE's and above need to dumb it down to terms a Finance major can handle.

Those 24 cell, 15v panels were not much use for battery charging because the battery needs 14.5ish to gas and these panels couldn't do it. ( Not enough spread between 15 and 14.5) So they went to 36 cell, 21v panels instead.

15v panels were the big thing for maintaining remote gel emg batteries many years agoThis would be a good maintainer using series diode protectionIt would offer low level slow recharge,Full top off, would take a very long time, but this could work well as storage..Or weekend extenderA boost gizmo would be a big help .. For weekend camping useBut not for storage use

I await mexicowanderer's input on this also.So if you need 14.5ish-15.0V to gas, you need 29 or 30 solar cells at .5V each to get that? At that point, does a charge controller become optional?The amps rating on this solar panel with PWM looks pretty darn good, if you could get the voltage to a usable level to recharge.Surplus voltage or head room, unless under direct sun, no clouds, looks a bit thin.

"Maximum Power Voltage ( Vmp)11.97V"I don't understand this either. I suspect it's in error.

2oldman wrote:"Maximum Power Voltage ( Vmp)11.97V"I don't understand this either. I suspect it's in error.It is not in error, there are only 24 panels on it, at .5V each. Most 12V Battery charging panels have 36 panels on them at .5V each, for 18 Volts output, under maximum load. They then burn some of it off with a charge controller to get it to 14.8 or 14.4V to charge a battery with.This is more a Power Supply panel for day time use, not a battery charging solar panel.

The 12V power source solar panel | Good Sam Community

49 Replies

BFL13
Explorer II
Oct 19, 2014
KD4UPL wrote:
Not enough voltage to charge a battery by itself. Put 2 in series and use an MPPT charge controller and it will work fine. You could put more than 2 in series depending on what the voltage limit of the charge controller is.

Two with my $13 gizmo limit at 32v almost as good as MPPT? Easier as a portable with two small panels instead of one big heavy one.
KD4UPL
Explorer II
Oct 19, 2014
Not enough voltage to charge a battery by itself. Put 2 in series and use an MPPT charge controller and it will work fine. You could put more than 2 in series depending on what the voltage limit of the charge controller is.
2oldman
Explorer II
Oct 19, 2014
JiminDenver wrote:
Get them cheap enough and you could run them in series.
That's a good idea.
JiminDenver
Explorer II
Oct 19, 2014
Get them cheap enough and you could run them in series.
NinerBikes
Explorer
Oct 19, 2014
2oldman wrote:
"Maximum Power Voltage ( Vmp)11.97V"

I don't understand this either. I suspect it's in error.

It is not in error, there are only 24 panels on it, at .5V each. Most 12V Battery charging panels have 36 panels on them at .5V each, for 18 Volts output, under maximum load. They then burn some of it off with a charge controller to get it to 14.8 or 14.4V to charge a battery with.

This is more a Power Supply panel for day time use, not a battery charging solar panel.
2oldman
Explorer II
Oct 19, 2014
"Maximum Power Voltage ( Vmp)11.97V"

I don't understand this either. I suspect it's in error.
NinerBikes
Explorer
Oct 19, 2014
I await mexicowanderer's input on this also.

So if you need 14.5ish-15.0V to gas, you need 29 or 30 solar cells at .5V each to get that? At that point, does a charge controller become optional?

The amps rating on this solar panel with PWM looks pretty darn good, if you could get the voltage to a usable level to recharge.

Surplus voltage or head room, unless under direct sun, no clouds, looks a bit thin.
MrWizard
Moderator
Oct 19, 2014
15v panels were the big thing for maintaining remote gel emg batteries many years ago
This would be a good maintainer using series diode protection
It would offer low level slow recharge,
Full top off, would take a very long time, but this could work well as storage..Or weekend extender
A boost gizmo would be a big help .. For weekend camping use
But not for storage use
BFL13
Explorer II
Oct 19, 2014
Those 24 cell, 15v panels were not much use for battery charging because the battery needs 14.5ish to gas and these panels couldn't do it. ( Not enough spread between 15 and 14.5) So they went to 36 cell, 21v panels instead.

Forum Discussion

The 12V power source solar panel

49 Replies

About Technical Issues

Related Content

Solar power

Newbie power question

Another solar question.

12 Volt Power Issue

solar powered electric vehicle.