Jackery hooked up to isotherm fridge?

Ghannan

Has anyone installed a 12V auto receptacle and plugged a 12V to 12V cable to a jackery for extending boondocking in deep shade?  We ran critically low on our 100Ah lithium battery last year after a couple days.  Power Watchdog detects a ground fault when the RV power cable is plugged into the Jackery.

Ghannan

FYI:  2023 tab 400, isotherm (130?) 12V fridge.

Grumpy_G

It's also more efficient to connect to the 12V side directly rather than going through the converter. My setup is very similar except my trailer is an older 320 so I have a 12V socket inside and a solar connector at the front tub already. I haven't needed to use my Jackery yet though. 

Cherokee

Indeed, I connect my portable solar system directly to the battery posts with large alligator style clips 

brianb

Did that exact thing on our 21 320S with our Jackery 1000. Fridge is either powered by our 100ah lithium or the Jackery. Added a rocker switch and 12V outlet next to the converter by the dinette. Made up a 18" cable with cigarette lighter plugs on both ends... Jackery to outlet.  Jackery lives under our bed as we leave it setup that way for most vacations. If needed we can take our Jackery to be charged somewhere, which rarely happens. And as a bonus we have 120V available to power a small appliance like the spouses coffee grinder!

Ghannan

Are the wires from the new outlet just spliced into the existing 12V fridge power wires, or are the new wires attached at the back of the fridge somehow?  Does the rocker switch just control the new wires, or does it disconnect the original power wires in addition to making the connection to the new 12V outlet, also?

AnOldUR

Assuming that your 400 has a cigarette lighter type outlet somewhere inside, all that you would need is a male to male extension cord to plug into the Jackery and that outlet. The cigarette ports are two way. You can back feed power into your trailer through them. When doing this you should turn the main battery switch off so that the two batteries don't balance which would leave both at less than optimal condition.

As for your Power Watchdog detecting a ground fault when the RV power cable is plugged into the Jackery, this is a workaround.

edit to add that we seldom need or use the small propane generator that we'll carry on longer trips, but I've bonded the ground and neutral internally. It has not presented any problems with our T@B.

Ghannan

I've read in some places that the Jackery has internal circuitry to reduce risk of shock (in the absence of a true ground), and the ground neutral plugs could be problematic for the Jackery, RV, or both.  I have to do more digging on that issue.  
I have thought about the 12v socket in the tab 400.  The isotherm seems to have a separate 7.5 amp circuit to it (control module in fridge?).  I'm not sure that would get power from the 12v plugin.  I suppose all 12v service would still be powered off of the one 12v input from the jackery??

brianb

I located and removed the wire going to the fridge on the terminal strip on the floor behind the WFCO converter and soldered to middle of the rocker switch. Soldered the existing yellow fridge wire from converter to rocker switch Soldered new wire from 12v cigarette lighter socket to the rocker switch. Drill holes to right of converter half way down from cushions for switch and 12V socket.

This was my solution to having extra battery capacity instead of my original plan of installing a second 100ah lithium battery. This was the right move for us and no regrets after 2 summers of use. Bonus we can use the 1000W Jackery for other uses and power outages.

Exert from my drawing of the electrical system on our '21 320.....

Ghannan

Thanks!  I will check this out .......

AnOldUR

Interesting approach @brianb. It might be helpful for anyone worried that they'd forget to turn off the battery switch when plugging their Jackery into an existing 12V port. The only downside that I see is that if you had a low power condition with your house battery, this setup will not power the other devices in your trailer like using an existing 12V port will.

Ghannan

Plugging in the Jackery 12V output into the 12V cigarette socket did power up the fridge, radio, lights, CO detector, etc.  with the lithium trailer battery disconnected.  With nothing powered on, but on standby, the Jackery was sending 6 watts to the 12V equipment via the fuse panel.  Turning on the Alde control panel drew 6 additional watts.   Lights drew a few more watts, except for the "accent lights", which drew upwards of 20 watts.  The fridge, when compressor was running, drew  about 46 watts.  In use, it has run for about 20 of every 60 minutes, for an average of about 15 watt-hours per hour, or nearly 1.3 amp-hrs per hour.  So, a 500 W hour Jackery (Explorer 500) should power all standby and fridge for roughly 500/20 = 25 hours!  My goal is emergency fridge power for 12 hours, so I think it will work for that.  
Thanks, all, for your help.

ColMag

Keep in mind the current (Amps) limitation of the 12V plugs and wire, and of the trailer outlet and trailer wiring. The spec'd safe limit is likely 10A. (And 10A is likely the limit from the Jackery outlet anyway? My non-Jackery similar power pack has a 10A limited 12V output). From the full Watts case you indicated you're up to about 6.7A. the Alde screen was on but maybe not the Glycol circulating pump?---That may draw a couple more Amps? In addition, the water pump may draw still a couple more Amps? The total may be over 10A when all is ON. Now, at least no wire insulation can overheat, since only 10A can come from the power pack anyway. But can the fridge or pumps be hurt if they can't get enough current? I don't know this, but if yes, I think one could put a 9A fuse in line from the power pack, so at least the fuse would blow before anything was hurt from being starved of current. Any electricians out there?

pthomas745

@ColMag The USB/12V ports are connected to 15 amp fuses in the converter.  This should give us a 180 watt "theoretical" limit on the 12V ports. I have plugged in small Viair compressor that is rated at 15 amps, and the 12V port handled it just fine. 

ColMag

That's good. But what about the limited 10A supply from the external power pack? If the fridge or pumps get starved of current, does that result in damage to them?

AnOldUR

@ColMag The Jackery Explorer 500 is fused at 10 amps to protect the circuitry. That is where damage would occur. Not in the device that it is powering. You will never be able to "starve" anything. Wiring somewhere before the device would fry if the fuse didn't blow.

edit to add that I just found that it's not actually a fuse:

The Jackery Explorer 500 does not have a user-replaceable fuse for the 12V cigarette lighter port. Instead, it uses an internal electronic protection system to prevent overcurrent and short circuits.

Reset the unit – Power off the Jackery, wait a few minutes, then turn it back on

ColMag

Ok then, so the Jackery cuts off the supply completely if more than 10A is attempted to be drawn. That would be the only protection needed for the trailer then. (Unless you still wanted to add your own backup 9-10A fuse for a margin of safety/redundancy.) I was thinking it just limits it to 10A and holds it at 10A continuously even if more than 10A was attempted to be drawn. I'll have to test my own non-Jackery power pack's 12V output to see if it behaves like that too. Thanks!

Ghannan

Good points, ColMag.   I don't know about dc motors, but I wouldn't want to run an ac motor on low voltage for fear of overheating it.  I know the water pump alone draws maybe 6 amps,not so, so that would be something to be concerned about if any lights, fans (including Alde fan and pump, which are rated at 1.9A/~24W).  If I go through with this as an emergency (keep the fridge running, I will need to make sure to not use the water pump unless the fridge is temporarily shut off.  Yes, the Jackery shuts off when the load exceeds 10A.  Of course, brianb's wiring/switch setup isolates the Jackery from other circuits (and vice versa, when Jackery is switched off near the fuse panel

pthomas745

I've read about "regulated outputs" on the Jackeries and various kinds of devices like this.  Honestly, this is all a bit over my head.  It seems, however, the newer "batteries in a box" have voltage outputs higher than 12V, in the 13.3 or so range. 

I'm not sure if this video changes anything about the discussion here, or the capabilities of the Jackery in the discussion. 

https://www.youtube.com/watch?v=ZXGYF1Ay0kU&t