Podmods, Maintenance, Tips and Tricks: Low Voltage disconnect installation

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Low Voltage disconnect installation

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Forum Name: Podmods, Maintenance, Tips and Tricks
Forum Discription: Ask maintenance questions, share your podmods (modifications) and helpful tips
URL: http://www.rpod-owners.com/forum_posts.asp?TID=15625
Printed Date: 19 May 2024 at 10:53pm
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Topic: Low Voltage disconnect installation

Posted By: Grinkle192
Subject: Low Voltage disconnect installation
Date Posted: 08 Mar 2023 at 3:54pm

I have an RPOD 192, it has a factory battery disconnect switch.

I discovered the hard way that the trailer brake emergency activation is on the battery side of the switch - it is not disabled by the battery cut-off switch. This is fine, makes sense, I just never thought about it. One doesn't want to de-activate the emergency trailer brake system by turning the battery cutoff to "off" after all.

When I winterized, I must have pulled the plunger out of the brake activator halfway - anyway, it was out enough to be active, but not enough for me to see that it was active, it wasn't all the way out and dangling by its cord, just about half-way out.

So when I go to de-winterize, I re-install the battery and there is plenty of sun so I assume the battery will stay charged. The brake activator draws about 6A full time when its active, I found later on in the course of my debugging. Anyway, dead battery, rinse and repeat while I convince myself I really do have a current leak. I drained and home-charged the battery three times before I figured out that I had a current leak and fixed the leak by pushing the brake plunger in all the way. By that time, I had destroyed my battery and had to buy a new one. It took some staring at the wiring to the cutoff switch and pondering - the leak wouldn't change whether the cutoff switch was on or off, so I kept suspecting the cutoff switch itself but it tested find when isolated. I finally noticed the brake plunger connection on the cutoff switch and figured out the plunger was not engaged and it was the culprit.

So I want to install a low voltage cut off as some battery insurance vs some other future mishap that I don't anticipate.

Does anyone have advice on where to install it? Ideally, it should go as close to the output of the battery cut-off switch as possible. I don't want to put it outside because its an active device and its not water-proof. It has the same form-factor and case as the battery cut-off. It might be ok outside, but I'd prefer inside. I see there is a roughly 12"x12" service panel cut out of the underside insulation right behind the battery cut-off towards the front of the camper, and if I take that off I can see what looks like a master-resettable fuse on the 12V line. That is a really cramped space to try and bolt this thing to the frame, but maybe that is just what I have to do.

Anyway, if anyone else has done this or something similar, any advice on where to mount would be welcome.

Thanks!

Replies:

Posted By: StephenH
Date Posted: 08 Mar 2023 at 8:22pm

I know that LiFePO4 batteries come with a battery management system (BMS) that shuts down the battery if the voltage drops down too low. There is likely something for Lead-Acid batteries. Perhaps something like this?

https://www.amazon.com/Battery-Protection-Undervoltage-Controller-Under-Voltage/dp/B07H4T3LS7 - https://www.amazon.com/Battery-Protection-Undervoltage-Controller-Under-Voltage/dp/B07H4T3LS7

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StephenH
Happy is the man that findeth wisdom,...

http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS

Posted By: Grinkle192
Date Posted: 09 Mar 2023 at 5:48am

I'm using this one -

http://www.amazon.com/dp/B00GZOP53M?psc=1&ref=ppx_yo2ov_dt_b_product_details - https://www.amazon.com/dp/B00GZOP53M?psc=1&ref=ppx_yo2ov_dt_b_product_details

I'm looking for advice from someone who's done a similar installation on where in the rig to mount it.

Posted By: StephenH
Date Posted: 09 Mar 2023 at 7:31am

I like the Blue Sea one better. It will take the amperage better than the one I linked.

As for where to mount it, near the battery is best. I expect the setting/override switch will be the bigger problem as wiring will need to be run to an accessible location to mount the switch. In my case, I already have a battery cut-off switch. It would be simple to remove that and put this device in its place. Since it is already inside, I would not need to run much wiring to put the switch in either.

-------------
StephenH
Happy is the man that findeth wisdom,...

http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS

Posted By: Grinkle192
Date Posted: 09 Mar 2023 at 9:08am

Yah, I agree running the switch wire is going to be a pain. The 192 has what can best be described as plastic corrugated cardboard sheets machine-screwed into the frame all along the underside, as a kind of undercoat-plating. Its great for insulation and protection, but lousy for servicing and up-fitting. To make the underside components (tanks, wiring, plumbing etc) visible involves removing a lot of machine screws and plastic panels, (not hard to remove, I expect replacement to be painstaking) but I guess that just going to be part of it.

Posted By: john in idaho
Date Posted: 10 Mar 2023 at 9:24am

It is good you fixed the emergency switch. An easy fix for the battery would be to just take off the pos. battery cable( or the Neg) until you figure out what you are going to do. Don't make it too complicated. I went for several years with no switch and the same two batteries just by taking the cable off. I think I am going to be replacing my two 6v GC batteries this year - noticed that costco has them in stock now. Got 8 years out of the first two, mainly by keeping the water topped up.

Posted By: jato
Date Posted: 10 Mar 2023 at 12:16pm

Originally posted by john in idaho

I think I am going to be replacing my two 6v GC batteries this year - noticed that costco has them in stock now. Got 8 years out of the first two, mainly by keeping the water topped up.

Good for you! Unfortunately batteries don't last as long as they should due to: not keeping the water topped up, drawing voltage below 12.2 before recharging and, keeping the posts clean of corrosion and acid. Curious as to what 'flavor' your two 6v batteries were that you are going to replace. Being in the golf business we have had the best longevity with Trojan batteries.

OTOH I still have an original battery that was purchased 1 month after taking ownership of a 2011 177 back in March 2011. It will be 12 years old next month and still performing well. It is a 12v Interstate group size 24 deep cycle. The original (which came with the 177 upon purchase was retired 2.5 years ago, it was the same type as above. The replacement battery which is now 2.5 years old is a Trojan T-1275, a heavy weight at 85 lbs. and puts out 150 aH, which is great for us who normally boondock. No solar or generator usage.

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God's pod
'11 model 177
'17 Ford F-150 4WD 3.5 Ecoboost
Jim and Diane by beautiful Torch Lake
"...and you will know the Truth and the Truth will set you free."

Posted By: john in idaho
Date Posted: 12 Mar 2023 at 11:02am

Those batteries were Trojans. I don't know how to compare the more expensive Trojans with the good price of Interstates at Costco , with their super guarantee .

Posted By: jato
Date Posted: 12 Mar 2023 at 4:58pm

Looked on the Costco website at the Interstates: They recommend recharging when the battery drops to 12.37v, curious as to why that is because with the Trojan T-1275 it is 12.2v. Also note that the Interstate 6v is rated at 175aH so by pairing two of these together do you still get 175aH at 12v or do you double the aH? A single T-1275 Trojan is rated at 150aH and although by itself the Interstates are a lot lighter at 58 lbs. each you will need a pair compared to a single Trojan at 85 lbs. and yes it is a monster to move around. And the 'super guarantee" is what on the Interstate? Don't get me wrong as my oldest Interstate has been fantastic being a few weeks away from 12 years of reliable service.

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God's pod
'11 model 177
'17 Ford F-150 4WD 3.5 Ecoboost
Jim and Diane by beautiful Torch Lake
"...and you will know the Truth and the Truth will set you free."

Posted By: StephenH
Date Posted: 12 Mar 2023 at 5:14pm

Assuming two batteries of the same type/age:

2 6V GC-2 batteries wired in series: Voltage doubles, amperage remains the same.

2 12V batteries wired in parallel: Voltage remains the same, amperage doubles.

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StephenH
Happy is the man that findeth wisdom,...

http://www.rpod-owners.com/forum_posts.asp?TID=7712 - ouR escaPOD mods
Former RPod 179
Current Cherokee Grey Wolf 24 JS

Posted By: Colt
Date Posted: 19 Mar 2023 at 3:53pm

You can't move the emergency brake to the "open" side of the disconnect? You would not tow with the disconnect open, because you'd want the truck to charge your battery. Then, the emergency brake system would be powered when you needed it.

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John
'16 R-Pod 180

Posted By: Grinkle192
Date Posted: 19 Mar 2023 at 3:55pm

I could, and I don't tow with the disconnect open, your use-case reasoning makes sense to me. Still, thinking about the low voltage shutoff, I want it for general use in any case.