Batteries and Fuses

[Bob Penn]

I retired after 20 years in the US Navy as an electronics technician. I know all about DC circuits and wiring!

It is important that if your trailer is going to be subject to potentially sub-zero temperatures, you remove your battery(s) when not in use during the winter. Being very responsible, I removed my 2 lithium batteries from my Casita last fall for storage in a warmer environment.

This spring, with "pie in the sky" plans for camping, I reinstalled the batteries. Perfect!

On my first trip, one of my 10 amps fuses blew. I checked everything, replaced the fuse and it blew again! Then another fuse blew. What is going on? Then one of the 40 amp main fuses blew! I could not find anything wrong. My electric tongue jack worked. All of the LED lights in the front half of the trailer worked. The exhaust fan on the stove worked.

Hours of testing, researching and still no clue as to my problem. So I purchased an endoscope (a camera on the end of a 16 foot stiff cable used for looking where you are physically unable to view it yourself) to look at the wiring behind my converter/fuse panel and other areas as well to no avail.

My nephew asked "are you sure you hooked up the batteries correctly?" Of course I have the batteries wired correctly. I am an expert! I spent 20 years working in electronics. Half of the DC loads in the trailer work. So, obviously I have the batteries hooked up properly!

More hours of frustration. I am now pulling the trailer apart trying to find that elusive short in my electrical system. I am extremely irritated when someone else says "Did you hook up your batteries correctly?". Of course, and followed with my expert reasoning why the batteries were NOT the problem!

In the mean time, I went to O'Rielly's and purchased enough fuses for my Casita to last you, me and the rest of the world for the next millennium. Remember the run last year on TP?

I am still blowing 40 amp fuses! This is serious! Now, both 40 amp fuses are blowing. Why not before?

In frustration, I decided I would start from the beginning and remove my batteries. As I am removing the batteries, I note that things do not look right.

I have the batteries wired backwards!

The next day, there was a post on Pinterest cautioning people about correctly connecting their batteries in their RV's. Talk about having a lesson hammered into your head loud and clear!

You will be quite pleased to know that everything works great when the batteries are properly installed.

I hope that my sharing my blunders help others to avoid my mistakes. I also provide this narrative in hopes of bringing some cheer to others on this forum, and particularly those other "experts".

[Glenn Baglo]

Originally Posted by Bob Penn

It is important that if your trailer is going to be subject to potentially sub-zero temperatures, you remove your battery(s) when not in use during the winter.

You don't need to remove wet-cell batteries.





The freezing temperature of the electrolyte in a fully charged battery is -92º F (-69º C).


Frequently Asked Questions | Trojan Battery Company

[Jon Vermilye]

You also don't need to remove lithium, although you can't charge them at under 32°F or draw from them at under -4°F. They will only lose a per cent or two of charge per month with no load...

[Bob Penn]

Originally Posted by Glenn Baglo

You don't need to remove wet-cell batteries.


The freezing temperature of the electrolyte in a fully charged battery is -92º F (-69º C).

Frequently Asked Questions | Trojan Battery Company

Thank you for the correction. I am still learning amazingly in my old age.

[Bob Penn]

Originally Posted by Jon Vermilye

You also don't need to remove lithium, although you can't charge them at under 32°F or draw from them at under -4°F. They will only lose a per cent or two of charge per month with no load...

Thank you for the correction and information.

I was told that I may discharge a lithium battery down to minus 4°F and up to I believe the temperature was 115°F. I was also told about the 32°F low limit for charging. I believe there is also a high temperature charging limit as well. Is the high limit for charging 115°F?


With everyone's corrections to my post, I am happy I will not need to remove the batteries from my Casita. It also means I will not repeat my mistake in connecting the batteries in the near future.


I very much appreciate everyone's feedback and information. Thank you.

[lawlopez]

At low temperatures the a led acid battery can not provide much power not can it be charged very quickly.

On balance it also doesn't self discharge very quickly.

So I disconnect the battery in winter and reconnect it on nice days and charge it up.
You only need to disconnect it if you have a parasitic load.
My 1993 toyota pickup is fine, my 1997 Lincoln Town car discharges unless I disconnect it.

I top up the toyota before each snow storm since it is the plow vehicle.

[AC0GV]

Originally Posted by Bob Penn

My electric tongue jack worked. All of the LED lights in the front half of the trailer worked. The exhaust fan on the stove worked.

.

The above items will work. The fan and jack may have been running the wrong way and newer LED lights will light both ways.

We get this every spring when people re-install their battery.
Think living space, like a house. My Scamp has this label.

[Bob Penn]

Originally Posted by AC0GV

The above items will work. The fan and jack may have been running the wrong way and newer LED lights will light both ways.

We get this every spring when people re-install their battery.
Think living space, like a house. My Scamp has this label.

Good points. What was throwing me off were the LED lights. I was not aware the newer ones are able to function regardless of the polarity.

I was and am very aware of the use of household color coding for wiring in an RV. However, when I installed the batteries this spring, my brain was obviously some place else. So the huge mistake. I will be putting labels on both ends of each of the wires so that neither I or anyone else should make the same mistake again. . . well at least that is the theory.

Casita have their battery connections clearly labeled. There is even a label on the battery compartment door making you aware of the color coding. Since my lithium batteries are not in the battery compartment, the label was not present as a reminder when I installed the batteries this spring.

It was not until I discovered I had the batteries connected backwards that I realized that the converter was what was blowing all of my fuses. Again, failure to really think things through. Particularly, when the obvious is right in front of your face.

[Raz]

Yup, stuff happens. I wanted a fuse at the battery so I went with an inline marine quality fuse with red leads. Amazon sells them. Now the positive is red.

https://www.amazon.com/420554-1-Wate...028912&sr=8-19

As for LED's the good ones have a full wave bridge on the input making them polarity neutral and a current source driver to maintain brightness over a wide range of voltages.

[Marv]

Bob,
It is kind of hidden, but the WFCO converter owners manual states that the only thing that can open those 40-amp fuses is connecting the battery backwards. I don’t know what the circuit is that allows them to say that but it must be correct.

[Bob Penn]

Originally Posted by Marv

Bob,
It is kind of hidden, but the WFCO converter owners manual states that the only thing that can open those 40-amp fuses is connecting the battery backwards. I don’t know what the circuit is that allows them to say that but it must be correct.

Marv, obviously you do not live by the mantra "Only read the manual/directions when all else fails".

Thank you for the information. Now that all else failed, I will read all about my converter. . .

[Marv]

Okay

[Huck]

Originally Posted by Bob Penn

Thank you for the correction and information.

I was told that I may discharge a lithium battery down to minus 4°F and up to I believe the temperature was 115°F. I was also told about the 32°F low limit for charging. I believe there is also a high temperature charging limit as well. Is the high limit for charging 115°F?

With everyone's corrections to my post, I am happy I will not need to remove the batteries from my Casita. It also means I will not repeat my mistake in connecting the batteries in the near future.

I very much appreciate everyone's feedback and information. Thank you.

I removed my 2 batteries today and took a picture of them wired up first. The factory didn't use standard color coding, so I figured the odds were pretty good I could screw up when I put the new batteries in. I still might!

[Perryb67]

Originally Posted by Bob Penn

Thank you for the correction and information.

I was told that I may discharge a lithium battery down to minus 4°F and up to I believe the temperature was 115°F. I was also told about the 32°F low limit for charging. I believe there is also a high temperature charging limit as well. Is the high limit for charging 115°F?

When I contacted Battleborn last winter they said, no charging below 32°F, no large draw furnace use preferably below 20°F, but small draw down to -5°F is OK, and if above 115°F the batteries can seriously degrade. This is what Battleborn told me, I believed them, and don't feel like arguing.

We have our camper stored in Minnesota winters when temps are traditionally around 0° F with no AC available. In the summer our batteries are located on the south side of our camper in a seasonal site where the sunny temps can easily get over 110 degrees in the middle of the day. Both situations are lithium no-no's.

We wanted batteries that could handle those situations for us. We purchased a pair of Soneil SiO2 batteries and are very pleased. Like lithium they charge much faster than AGM's and have a long life (cycle) potential, but function down to -40° F and up to 145° F. Their drawback is they weigh the same as standard lead acid batteries, not a problem for us.

I agree that lithiums work for a vast majority of RV owners, but for a few of us they're not the answer. Because of SiO2's weight they'll never be a major player, but for us outliers they'll work in our situations.

Food for thought,

Perry

[jwcolby123]

LiFEPo4 chemistry

Heated LiFePo Battle Born

On YouTube Look up Will Prowse, Off-Grid Garage. Neither are RV specific but tons of good info.

[jwcolby123]

There is no putting the magic smoke back in the bottle!

[skipperclyde]

You should have listened to your nephew, he sounds like an expert.

[Deb Mac]

Originally Posted by Perryb67

We have our camper stored in Minnesota winters when temps are traditionally around 0° F with no AC available. In the summer our batteries are located on the south side of our camper in a seasonal site where the sunny temps can easily get over 110 degrees in the middle of the day. Both situations are lithium no-no's.

We wanted batteries that could handle those situations for us. We purchased a pair of Soneil SiO2 batteries and are very pleased. Like lithium they charge much faster than AGM's and have a long life (cycle) potential, but function down to -40° F and up to 145° F. Their drawback is they weigh the same as standard lead acid batteries, not a problem for us.

I agree that lithiums work for a vast majority of RV owners, but for a few of us they're not the answer. Because of SiO2's weight they'll never be a major player, but for us outliers they'll work in our situations.

Food for thought,

Perry

Same situation here Perry. My trailer is stored outside in BC mountains. We get similar temps in the winter - down to -20-30C and up to +30-35C in the summer. I can leave mine plugged in over winter, but that wouldn't help if I had lithiums. I like to putter inside on the slightly warmer days - I can turn on the heater and work inside.
For the same reason, I got a SiO2 battery from Sonneil. It has the advantages of the Lithium combined with those of LA. Safe, and no off-gassing at all while charging, and can charge and discharge under those cold & hot conditions. Capable of full discharge without damaging the battery. Not as long-lasting as Li-ion, but also 1/3 to 1/2 the price.

They are heavy - Yep, but the nice thing for me is that because they do not off-gas at all, and are non-explosive, they are perfectly safe to keep inside the trailer. I have it under the front bed about 4' back of the hitch, where a fair percentage of that weight is taken off the tongue. I have a Bigfoot, with a dry tongue weight of 380 lb on a 2600 lb dry weight trailer. Add 40 lb of propane and a 75 lb battery and you are at the hitch limits of my TV (500 lb). So to be able to double my useable Ah (108 Ah) and take a bit of weight off that tongue works for me. By balancing my load, I can keep that tongue weight around 400-420 lb, with a trailer weight at about 3200 (I travel light). Which is a respectable tongue to load ratio

I had considered a couple of 6V golf cart batteries, but with no where to put them except the tongue where the old 12V "deep cycle" battery was, that would add a good 70-80 lb to the tongue above the 65 lb that the original battery weighed - which is not included in the dry weights. Would have cost just as much, and wouldn't have given me any more useable Ah than the one SiO2.

[THene1713]

I told the story (recently elsewhere) of LAST YEAR disconnecting coach battery to replace hydraulic electric solenoids, and still had voltage; thinking another solenoid welded shut, disconnected chassis battery; still had voltage; looking perplexed, I told wife my problem and she says "You are STILL PLUGGED IN"... SO I DECIDED I NEEDED TO DO that JOB ANOTHER DAY, LOL :-)

[jwcolby123]

I'm trying to replace my dead lead acid with my shiny new LiFePO.

The old is in a battery box on the front rail of my 1995 19' Scamp. Waaaayyyy too heavy to lift by the straps out of the battery box.

The battery box is bolted down with two bolts / nuts through the bottom of the box. Which bolt is just spinning as i try to remove the nut, thus the box cannot come out (easily).

I have no grinder to cut through the bolt, though there is about 1/2" of thread showing if I did. I could just cut through that bolt, then lift the entire box off the mount.

But no...

Further the wires are a single pair of ... at best about 12 gauge. Which any gauge chart will tell you is good for 20-30 amps. My old Flooded Lead Acid and the wimpy loads presented were no doubt fine with that. But my shiny new LiFePO is rated at 100 amp charge / discharge. Which informs me that new wiring is in order.

All the wires are pulled through the raised floor as far as I can tell?

I'm thinking about just abandoning the current battery location, moving the battery inside (somewhere). The charger, oddly is under the drivers side rear bench seat in the rear dinette. AC comes in the other side. Weird if you ask me.