Charge controller ?

[Muddydogs]

I don't guess I completely understand what my charge controller does and doesn't do so here is a question.

I have a PWM solar controller hooked up to 200 watts of solar and 2 group 24 battery's, controller is adjustable for shut off volts.Do I need to worry about changing the shut off volts while in storage or does the controller take care of the battery's and won't over charge them?

Say I have the controller set to shut off at 14.4 volts while I'm using it, should I change the shut off to 13.4 volts in storage?

Also where should I set the top end shut off, 14.4, 14.6 or ?

Thanks, Jim S.

[Almot]

Muddydogs wrote:

I just wired up a 750 watt inverter and ran wire into the trailer for a dedicated inverter plug so I could power the TV and DVD player off the batterys but see no since in using it to charge phones, besides I leave the wall plugs at home and have chargers in the truck for phones so its easy to grab a charger out of the truck and use it in the trailer.

Yes, you can use 12V chargers for cell phones, this would require enough cig lighter receptacles for all your 12V chargers. Normally there is only one such receptacle, while 110V receptacles are all over.

Or you can charge your cell phones off the same 110V inverter plug that you use for TV/DVD, or another 110V plug in parallel. Get a few spare wall warts, second hand stores will have those for $2. Low-wattage inverters don't - usually - need a lot pf power for their own circuitry, so it won't make much difference from using 12V chargers.

[Muddydogs]

Almot wrote:
I think the easiest way to charge small electronics is via their OEM wall wart and a cheap inverter like this one. Doesn't matter day or night.

I have an inverter in my trailer but why when you have 12 volt powder running throughout the trailer would you bother with an inverter and wall plug. I wanted to be able to charge phones or grand kid games things so I hooked a 12 volt plug into a run of led lights in the cabinets in the living area. I was either going to use the charge controller in the bed room or hook into the led lights above the bed to get powder to run a 12 volt plug. When power is a premium while dry camping the last thing I would want to do is powder an inverter and charge phones all night. Just the wiring for an inverter isn't worth it when 12 volt power is right there.

I just wired up a 750 watt inverter and ran wire into the trailer for a dedicated inverter plug so I could power the TV and DVD player off the batterys but see no since in using it to charge phones, besides I leave the wall plugs at home and have chargers in the truck for phones so its easy to grab a charger out of the truck and use it in the trailer.

[Almot]

Muddydogs wrote:
my controller also has Floating charging voltage adjustment I don't understand.

Floating voltage adjustment is - mostly - for when you change the battery to a different brand/model/type.

Muddydogs wrote:
Another question you brought up, I was planning on using the load terminals off the controller to hook up a 12 volt plug to charge cell phones at night. Controller is in the bedroom and I would like to charge my phone at night so I was thinking the easiest way would be to hook into the controller load terminals then to run more wire.

I think the easiest way to charge small electronics is via their OEM wall wart and a cheap inverter like this one. Doesn't matter day or night.

[mena661]

Golden_HVAC wrote:

The 14.2 volt cut-off is to allow the voltage to be high enough that it will break up any sulfites on the battery plates. Storage or not, they still need to come off.

Yeah but that doesn't need to be done everyday.

[Muddydogs]

BFL13 wrote:

Muddydogs wrote:
I'm wired up with around 6 feet of 4 gauge between controller and battery's. Controller seems to be showing the same voltage as my voltage meter but I will keep an eye on it to make sure its not running a little hot.

Eventually I will pick up some group 27 battery's but do to certain events and my lack of paying attention I ended up with 2 24's. Learned another lesson in life.

Thanks for the help guys.

The controller's voltage display and ammeter display are accurate on mine. It is the voltage adjustment setting that has the index error mentioned.

To be clear, you set whatever and let it run till voltage stops rising and stays there. The difference between that actual voltage and what you set it at, is the index error to correct for.

Ok I understand now, thanks for the heads up.

[Golden_HVAC]

I think that it should shut off at 14,2 volts while camping or in storage.

The 14.2 volt cut-off is to allow the voltage to be high enough that it will break up any sulfites on the battery plates. Storage or not, they still need to come off.

You might need to add a little more water with the 14.2 volt setting, but overall it really does not matter than you need to add a few ounces of water every 2 months anyway, what is 1 extra ounce of water?

Group 24 battery is pretty small. I use a pair of 67 pound golf cart batteries. They offer a total of 220 amp hours at 12 volts.

Your RV will use a total of about 35 amp hours per day to run the CO meter, propane detector and refrigerator. Anything else that you run will be on top of those basic loads.

Good luck!

Fred.

[BFL13]

Smk, the programming may be "weak" but it beats the heck out of other $30 controllers. This one even has an ammeter and displays battery voltage and solar amps where most of them that price range have just a row of red lights to show charging progress.

[time2roll]

3.4.9 Over Voltage Disconnect Interface
The value displayed in this interface is the value at which the charge controller will stop charging the battery.
When the battery voltage reaches this voltage, the controller will disconnect the charging solar panel(s) to
prevent the battery from overcharging. After the battery voltage drops below the Over Voltage Disconnect
value, the controller will reconnect the charging solar panel(s).

NOTE: To change the OVD value, press the ‘MODE’ button for over 5 seconds until the number starts to
blink / flicker. The controller will enter the adjustable mode, where you can use the ‘UP’ and ‘DOWN’ buttons
to adjust the parameter. After the value has been set, press the ‘MODE’ button for over 5 seconds to exit the
adjustable mode and store the setting

As it appears this is the only set point I certainly recommend a lower voltage for storage. 13.2 - 13.4 volts would be better. Apparently you also need to keep a watch on actual voltage for a few days so that you know what this controller is actually doing.

Battery still need to be fully charged before you lower the voltage.

BTW I don't like this controller as the programming is weak.

[BFL13]

Muddydogs wrote:
I'm wired up with around 6 feet of 4 gauge between controller and battery's. Controller seems to be showing the same voltage as my voltage meter but I will keep an eye on it to make sure its not running a little hot.

Eventually I will pick up some group 27 battery's but do to certain events and my lack of paying attention I ended up with 2 24's. Learned another lesson in life.

Thanks for the help guys.

The controller's voltage display and ammeter display are accurate on mine. It is the voltage adjustment setting that has the index error mentioned.

To be clear, you set whatever and let it run till voltage stops rising and stays there. The difference between that actual voltage and what you set it at, is the index error to correct for.

[pianotuna]

Hi,

The float voltage is a bit high for storage, but probably fine for when in use. 13.2 may be better for storage.

I would not use the load terminals for charging.

[Muddydogs]

I'm wired up with around 6 feet of 4 gauge between controller and battery's. Controller seems to be showing the same voltage as my voltage meter but I will keep an eye on it to make sure its not running a little hot.

Eventually I will pick up some group 27 battery's but do to certain events and my lack of paying attention I ended up with 2 24's. Learned another lesson in life.

Thanks for the help guys.

[NinerBikes]

Rough rule of thumb for stuff like group 24 batteries, which can be a PIA to get top charged... Set your unit at 14.8V when charging while camping, and I'd set it at 13.4V when you completely disconnect the battery from the camper, but leave just the solar panel connected while in storage.

14.8V camping
13.4V storage

The Chinese are banking on you being cheap, and running thin gauge copper wire from the charge controller to the battery, which will create DC voltage losses, depending on the length of the copper wire run and how close the controller is or isn't to the battery.

Don't be cheap, run fat wire, your battery will last a lot longer running the fat wire and staying top charged like it should

[BFL13]

The P30L is a Solar30. I have a Solar30. The one voltage you set is the charging voltage which is also the floating voltage. That is, the controller lets the batteries get to that voltage and then holds that voltage there the rest of the day until the light fades and it can't maintain that voltage anymore.

While camping I set mine to 14.8 volts. For not camping (storage float battery maintaining only) I would set it at 13.4 or whatever depending on ambient temperatures at the time--80F is 13.2v, 50F is 13.8v eg.

EDIT: first time out, check the actual battery voltage when the controller gets to the voltage where it stops rising. My Solar30 overshoots a little on the setting (so does Niner's) so to get it to stop at 14.8 I have to set 14.3. Once you know the amount that's it, it stays the same for any setting. I can get mine to to go to 15.5 when the max setting is 15, eg.

I suppose you could run loads like that but you can also just use the 12v socket in the Winegard TV panel. If you have an inverter, you can use that with whatever charging adapter your gizmo uses. Some inverters have USB for that. When on whole house inverter you can stick one of those 120v-to USB adapters in any 120v receptacle in the rig and use that.

[Muddydogs]

BFL13
Yes I now I can adjust the load voltage but my controller also has Floating charging voltage adjustment I don't understand.

Another question you brought up, I was planning on using the load terminals off the controller to hook up a 12 volt plug to charge cell phones at night. Controller is in the bedroom and I would like to charge my phone at night so I was thinking the easiest way would be to hook into the controller load terminals then to run more wire. Good idea or not?