Juice Pack and Battery Disconnect Question

[ktreffin]

Hi folks!


Brand new member of the forum and new owners of a 2012 Alpha Wolf 27RK-L. I have a couple of questions concerning the "Juice Pack" and the 12v battery disconnect switch which I haven't been able to find an answer for - When not in use, we keep our 27RKL in storage; when doing this, should the batteries be disconnected, or should the battery disconnect be left in the "on" (not disconnected) position? Will the Juice Pack still charge the battery if the battery is disconnected by the switch? I apologize for a seemingly easy question but I have not been able to find a definitive answer.



Thanks for any and all help. I am glad to be a part of the forum and I have learned a lot from reading through the posts.


Ken

[J_RV]

I had the same question. The answer I received from the dealership was yes the battery will receive the full charge from the solar when the disconnect is in the disconnect position.

[ktreffin]

Originally Posted by J_RV

I had the same question. The answer I received from the dealership was yes the battery will receive the full charge from the solar when the disconnect is in the disconnect position.

Awesome! Thanks for the help. I couldn't for the life of me find a definitive answer on it. Thanks again. I sure do appreciate it.

[TowPro]

what is a juice pack?


if a juice pack is your factory solar, than it should charge the battery when battery switch is turned off.


if a juice pack is the 120V to 12V convertor, then first, for it to work you must be plugged into 120V, and there is a pretty good chance this will not charge your battery if switch is turned off.

[BehindBars]

I’ve lately seen this term “juice pack” used freely as if it is universally known to mean something. Is Juice Pack a formal name for a Forest River option or an aftermarket product? Is is just a generic name for a solar panel system, or is it something else?

If I search the internet on juice pack, the below picture is what I get:

[NMWildcat]

Originally Posted by BehindBars

I’ve lately seen this term “juice pack” used freely as if it is universally known to mean something. Is Juice Pack a formal name for a Forest River option or an aftermarket product? Is is just a generic name for a solar panel system, or is it something else?

If I search the internet on juice pack, the below picture is what I get:

Love it! Made me chuckle.
Looks like it's just an option for Cherokees that is a complete solar system. Guess 'Juice Pack' is just a catchy marketing label.
https://www.rvwholesalesuperstore.co...-rv-spotlight/

[Jim CB]

Juice Pack is Forest River's name for a solar power system.

[TowPro]

in that case, it should be wired direct to solar full time to keep the battery charged in storage. on my MBS it actually first chargers the 2 onboard 27 series AGM's, than switches over to charge the single chassis battery


100W does all this with no problem, but I would not expect that 100w to keep the RV charged while trying to use it camping.

[ktreffin]

Hi Everyone,


My apologies about the confusion involving the "juice pack" name. Here is some additional information that might help clear things up:


Keep Your Cherokee Going with the New Juice Pack Option

Roof Mounted 50 Watt Solar Panel

More and more RV owners are considering aftermarket solar panels for their RVs. This trend has influenced the manufacturers to include “solar ready” wiring to many of the RV models available today. But the new Cherokee Juice Pack option lets you get your new 2020 Cherokee RV with a solar panel already installed. This eliminates the risks and hassles of aftermarket upgrading.
With the Juice Pack, solar energy trickles in to charge the battery all day. This helps keep your battery adequately charged at all times. The solar power harnessed from the Juice Pack is strong enough to keep the 12-volt system ready to use for things like the power jacks and awnings without needing to be plugged in to a power source.


Thanks for all of the replies. I do appreciate the assistance.


Enjoy your day,


Ken

[Bhrava]

They added the "Juice Pack" when they went to the 12v refrigerators. It's an option that is "supposed" to allow the reefer to run all day on solar, and on battery at night. It doesn't though.

For it to actually work, you need two batteries and the second 50W panel connected. I tested it last week when I had to repair the power cables to my barn, so ran the reefer on the solar. It made it over night, but during the day the voltage must have dropped below the reefer threshold and stopped the compressor. When I checked later in the day the battery was at 11.3 and charging, but the reefer was off, and 65* inside. Once I got power restored and the converter back online the reefer started cooling again.

To answer the OP question, the solar connection is wired to the positive battery side of the cut off switch, so yes it will continue to charge the battery when the main is switched off. There is another wire that leads into the trailer from the battery side, but have not determined where it terminates, so there is at least one other item that is powered by the "Juice pack", possibly it is the Reefer, but haven't tried it yet.

[21wolfpupfq]

Originally Posted by Bhrava

They added the "Juice Pack" when they went to the 12v refrigerators. It's an option that is "supposed" to allow the reefer to run all day on solar, and on battery at night. It doesn't though.

For it to actually work, you need two batteries and the second 50W panel connected. I tested it last week when I had to repair the power cables to my barn, so ran the reefer on the solar. It made it over night, but during the day the voltage must have dropped below the reefer threshold and stopped the compressor. When I checked later in the day the battery was at 11.3 and charging, but the reefer was off, and 65* inside. Once I got power restored and the converter back online the reefer started cooling again.

To answer the OP question, the solar connection is wired to the positive battery side of the cut off switch, so yes it will continue to charge the battery when the main is switched off. There is another wire that leads into the trailer from the battery side, but have not determined where it terminates, so there is at least one other item that is powered by the "Juice pack", possibly it is the Reefer, but haven't tried it yet.

I don't understand why it would stop cooling during the day when the solar panel should already be charging. What was the battery voltage when the shore power was disconnected? Where was the ref temp setting set to? I believe I've had mine on boondack/camping power setting for a day or two and never seen the voltage drop below 12v while parked in my driveway and shore power is disconnected.

I also have that setting when traveling(full of food) and have stopped for restaurant dine-in dinner or lunch on occasions with the TV powered off(probably 1.5-2 hrs) and had no issue with cooling or starting the TV. Next trip(6-7 hrs) I'll check the temp before leaving and upon check-in to confirm.

Not arguing or criticizing , just trying to learn. Thanks

[babock]

So hilarious that they think a 50W or even 2 50W panels is going to do hardly anything to allow you to operate a 12V fridge. Nice catchy name for pretty much nothing.

[Bhrava]

Originally Posted by 21wolfpupfq

I don't understand why it would stop cooling during the day when the solar panel should already be charging. What was the battery voltage when the shore power was disconnected? Where was the ref temp setting set to? I believe I've had mine on boondack/camping power setting for a day or two and never seen the voltage drop below 12v while parked in my driveway and shore power is disconnected.

I also have that setting when traveling(full of food) and have stopped for restaurant dine-in dinner or lunch on occasions with the TV powered off(probably 1.5-2 hrs) and had no issue with cooling or starting the TV. Next trip(6-7 hrs) I'll check the temp before leaving and upon check-in to confirm.

Not arguing or criticizing , just trying to learn. Thanks

Well, had I actually read the manual, lol, I would have known to switch it to the off grid setting. Apparently, the Off Grid setting is designed to run off the battery. Will see, we had some bad storms rip through yesterday and knocked the power out in this area for several towns, can't even get gas anywhere locally, so while my house is on generator, the Bulldog won't allow power to the trailer due to the floating ground of the generator, so it is on 12v only. I will go out and check in a bit to see what the battery voltage is at and the fridge status. I have the off grid set now.

[21wolfpupfq]

Confirming that ref's off-grid setting does run/hold the temp while on the road(7 hrs travel each way which includes TV powered off for about 1-1.hrs for lunch). Voltage reading(from panel) never drops below v12.x

[Bhrava]

On a 105AH battery, it lasts about 10 hours with the solar panel helping, when on the off grid setting. It will not last overnight though, by morning 60* interior temps both boxes. I also traced the wires coming off the battery. The solar is connected directly to it and so is the break-away brake circuit, everything else is behind the disconnect, so the only draw would be the brakes if activated, and the panel does charge it fully in a few hours depending on how low the battery is. It went from 11.7 to 12.9 in around 6 hours. The 12v fridge apparently shuts off below 12v and not the 10.5v in the manual.

I also measured the air exiting the bottom and it is 96*.

[babock]

Originally Posted by Bhrava

It went from 11.7 to 12.9 in around 6 hours.

Which isn't even close to being charged.

If you let your battery get down to 11.7V multiple times, time to buy a new battery.

[Bhrava]

Originally Posted by babock

Which isn't even close to being charged.

If you let your battery get down to 11.7V multiple times, time to buy a new battery.

According to this chart it is

Here are no-load typical voltages vs state of charge
(figured at 10.5 volts = fully discharged, and 77 degrees F). Voltages are for a 12 volt battery system. For 24 volt systems multiply by 2, for 48 volt system, multiply by 4. VPC is the volts per individual cell - if you measure more than a .2 volt difference between each cell, you need to equalize, or your batteries are going bad, or they may be sulfated. These voltages are for batteries that have been at rest for 3 hours or more. Batteries that are being charged will be higher - the voltages while under charge will not tell you anything, you have to let the battery sit for a while. For longest life, batteries should stay in the green zone. Occasional dips into the yellow are not harmful, but continual discharges to those levels will shorten battery life considerably. It is important to realize that voltage measurements are only approximate. The best determination is to measure the specific gravity, but in many batteries this is difficult or impossible. Note the large voltage drop in the last 10%.

State of Charge 12 Volt battery Volts per Cell
100% 12.7 2.12
90% 12.5 2.08
80% 12.42 2.07
70% 12.32 2.05
60% 12.20 2.03
50% 12.06 2.01
40% 11.9 1.98
30% 11.75 1.96
20% 11.58 1.93
10% 11.31 1.89
0 10.5 1.75

https://www.solar-electric.com/learn...tery-faq.html/

[babock]

Originally Posted by Bhrava

According to this chart it is

Here are no-load typical voltages vs state of charge
(figured at 10.5 volts = fully discharged, and 77 degrees F). Voltages are for a 12 volt battery system. For 24 volt systems multiply by 2, for 48 volt system, multiply by 4. VPC is the volts per individual cell - if you measure more than a .2 volt difference between each cell, you need to equalize, or your batteries are going bad, or they may be sulfated. These voltages are for batteries that have been at rest for 3 hours or more. Batteries that are being charged will be higher - the voltages while under charge will not tell you anything, you have to let the battery sit for a while. For longest life, batteries should stay in the green zone. Occasional dips into the yellow are not harmful, but continual discharges to those levels will shorten battery life considerably. It is important to realize that voltage measurements are only approximate. The best determination is to measure the specific gravity, but in many batteries this is difficult or impossible. Note the large voltage drop in the last 10%.

State of Charge 12 Volt battery Volts per Cell
100% 12.7 2.12
90% 12.5 2.08
80% 12.42 2.07
70% 12.32 2.05
60% 12.20 2.03
50% 12.06 2.01
40% 11.9 1.98
30% 11.75 1.96
20% 11.58 1.93
10% 11.31 1.89
0 10.5 1.75

https://www.solar-electric.com/learn...tery-faq.html/

Your 50W panel puts out a max of around 2.5A. If it was 100W 5a. That output is if it is tilted. If it is flat, it is 70% of that. You can't charge up a 105AH battery that is at 30% SOC to 100% in 6 hours.

BTW, that voltage chart, only applies if the battery is at rest with no load and any surface charge dissipates over an hour.

So...when were you measuring this 12.9V? Was it charging with the solar still? The battery has to reach over 14V to be fully charged while you are actually charging.

If you are in a southern area like I am, you can get 5 equivalent sun hours. That means the panel is exposed to the sun all day long to get those equivalent 5 hours. Your 50W panel would yield max 12.5AH if it was in the sun all day and tilted towards the sun. If it is flat, will be closer to 9AH...that is for an entire day.

[Bhrava]

It charged with no load, had the main disconnected. Just reporting what the meter showed when I walked out around 2 PM that day. Meter read 11.7 at 8 that morning, 12.9 when I looked at 2 PM. It is what it is.

[babock]

Originally Posted by Bhrava

It charged with no load, had the main disconnected. Just reporting what the meter showed when I walked out around 2 PM that day. Meter read 11.7 at 8 that morning, 12.9 when I looked at 2 PM. It is what it is.

The solar panel is still connected to the battery with the battery disconnect off.

Did you not look at the math I just posted?