Charge voltage needed for 24 V system

[sdold]

...and have wired 2 12v panels in series. Open voltage of the panels is 24 v

A typical 36-cell "12v" solar panel open-circuit voltage will be around 20 volts. If you have two of them in series you should be seeing an open-circuit voltage of over 40 volts, not 24V.

[littleharbor]

In a nutshell. how many panels and what's their Voltage? That's very low voltage for anything over a single 12 volt panel. I've seen panels put out substantial voltage with a towel over them.

[Anger Managment]

No wired in series just very overcast and snowing quite a bit when I posted that comment

[littleharbor]

15.4 volts. Sounds like your panels are parallel wired.

[SunEagle]

And what is the death voltage you speak o🤔

The death voltage would be something that exceeds the rated Maximum DC input voltage rating of the CC.

As Mike stated, the cheaper CC's have lower DC input voltages which can be exceeded if you wire too many panels in series and on a cold morning the voltage spikes beyond what the CC can handle.

[Anger Managment]

And what is the death voltage you speak o🤔

[Anger Managment]

As previously stated I have the panels wired in series and they are producing 15.4v now with sky clearing. So this should start to charge the batteries I'm hoping

[Mike90250]

If your panels are in full sun and aimed, well, I would wire them in series, avoiding the death voltage of the controller.

Small controllers may go to 50V, Mid size 75V, Read the specs carefully for max voltage and the Voc of the panels.

[Anger Managment]

Thanks for quick answer to my question, here's another from a solar newbie😌 I have purchased a MPPT charge controller and have wired 2 12v panels in series. Open voltage of the panels is 24 v and I'm going to charge 12v battery on a cloudy day like today the voltage of panel array is 9.8v so I am under the voltage to provide a charger to the batteries is this correct? Or will this lower voltage act like a trickle charge? I'm not really sure if this voltage will charge the batteries and with 2 12v batteries does the voltage get split between the batteries?
I am in the process of purchasing 6 panels from another gentleman who is moving and can't take his system with him, 4 panels are 12v and 2 are 24v with the option to configure them to 12v by removing a diode jumper.
Would it be better to wire the panels to 12v or 24v ?
I guess this is more than one question and for that matter not a quick question.
Thanks in advance

[Mike90250]

I'm just coming into this conversation a bit late but are you saying that A 12v solar panel is unable to charge a 24v battery? thanks for your reply to a newbie in the solar world 🌎

Correct. A 12V battery, on occasion, needs 15-16 V for proper charging, A "12v" soalr panel often provides 21V to charge a 12v battery. Run that through a charge controller, and you loose a couple more volts in the controller.

Double all the 12v requirements for a 24v battery

[Anger Managment]

I'm just coming into this conversation a bit late but are you saying that A 12v solar panel is unable to charge a 24v battery? thanks for your reply to a newbie in the solar world 🌎

hi ..need a little help .. i have 2 solar panel probably more the 100 watt each the are the same but i don't know the model .
i have connected them in series to aw solar charge controller CS5024Z to 2 batteries (AGS 200) i don't know whether they are 12 volts or 24 volt .. can you tell me should i connect the panels in series or change it to parallel and also when we need high voltage and when we need high amp.

[Mike90250]

You need to have at least 35V for full charging and equalizing functions, so you have to wire 2 panels in series to get 64V. and then use a true MPPT charge controller to charge the batteries.
This would give you 3 strings of 2 panels. With 3 strings, you need to use a solar Combiner Box when you wire the 3, 64v strings in parallel

[bronola]

I have 6 32 volt solar panels and want to have a 24 volt system. what do I need ?

[KyMtMan]

New to this forum and the reason I joined is the knowledge that some members posses is phenomenal. I recently installed 6.3kw system with Enphase inverters and I have 8 ea. of 255 watt panels yet to install in another array. I purchased 2 1200 watt inverters from China but could not find but little reviews on them. My system is a grid tie system. I need a battery backup so I purchased a 1800 pound battery from a fellow near by. The battery appears to be in good working order. It holds a charge very well and the specific gravity is at 2.1 which is a bit low but was informed that the batteries will last longer with a low sg. I hooked a 255 watt 30+ volt 8a panel and it is charging well I think. The battery is 875 amp hours and requires 20amp to charge. will this be enough to charge the battery and how long will it take is my question? Any advise would be greatly appreciated....