questions on battery charging

[riven1950]

I have a small 110V battery charger, nothing fancy , I think it has 2,6,10 amp selections.

Anyway, I was thinking about hooking short wires to the + and - terminals of my battery permanently and let them stick out of the battery box to make for easy charging. Not sure what you would call them, I'll call them pigtails.

Does this make sense? How would they connect to the charger which has aligator clips on it? Are these commercially available?

Other question concerns charging. I have always disconnected my battery before charging or turned off my battery disconnect switch.

Does it hurt to use a 110v battery charger while the battery power to the trailer is on and the frig is running on propane?

I have a 2017 Coachmen TT with one battery if that matters.

Not a battery expert obviously, just trying to be safe.

Thanks

[riven1950]

Thanks 4x4van,

Since charging time is not an issue I am good with either one.

I will order one this weekend for our trip next month. Saves me some engineering and thinking 🙂

[4x4van]

Puck style

[4x4van]

Here's a pigtail style

[riven1950]

I'll look but think I would rather have a pigtail.

Thanks all

[4x4van]

I just use this small 15A/30A Puck, but I'm sure that a short 15A/30A twist version is available.

[riven1950]

4x4van, I appreciate the input. Actually you have me rethinking. 1- will look for a 30amp twist to 15amp adaptor. Something a couple feet long would be great. 2- I was thinkng charging with the converter would be slower, but if not it would work.

On edit: I quickly found an adaptor online. So I guess if charging time is not an issue then I was really overthinking the thing.

[4x4van]

Whatever. The extension cord is going to be across the street either way, so what is the difference whether it's plugged into a charger or plugged into your shore cord with a 15A/30A puck (like this, for just $2: https://www.walmart.com/ip/Aleko-Rv15M30Fa-15A-Male-To-30A-Female-Adapter-Plug/47200149?wmlspartner=... ) And your built in converter is more than likely a better charger than your simple stand alone battery charger. Probably outputs a full 45A to start, tapering down as needed as the battery SOC comes up. But do what you want; I'm just not seeing an advantage.

[riven1950]

OK, FYI , I do exactly as you say at home. Plug in to 15amp outlet in my shop with a pigtail adapter to my tt 30amp cord.

The situation I asked about comes from visiting my daughters home in Jax. Cannot park in front of their house. I have to park across the street. Will have to run a cord across the street ( after a couple of days of use ) to charge the battery. Will do this at night when traffic is less.

I don't have a short twist 30 amp to 15 amp adaptor cord, which I guess would work. Definitely don't want my 30amp 25' cord sitting out, it might walk off. It is a nice neighborhood but i'd rather just risk a charger and ext cord to theft.

Plus I am thinking the battery charger would charge faster than the tt converter. Is that correct?

[4x4van]

The OP has a 2017 model trailer; I highly doubt that it uses a "cheap" converter. He also wants the fridge on, which means that the battery switch must be on and connected, along with all of the other items you list. Hooking up an external battery charger while leaving the battery switch on isolates nothing, protects nothing, and accomplishes nothing other than complexity vs simply plugging his trailer in.:R

[Lynnmor]

4x4van wrote:
Yes, stand-alone battery chargers, battery tenders, float chargers, etc are great...as are connectors, plugs, pigtails, hookup studs, etc...for a vehicle that doesn't already have a battery charger in it. What am I missing? :h

Some of us don’t want to power up the entire trailer to keep the battery charged. We know that exposing things to power issues like lightning isn’t a good thing. Operating circuit boards in TVs, radios, refrigerators, water heaters and furnaces is a waste of energy and may lead to early failure. Some of us have cheap converters that may not do as good of a job charging a battery as some of the small tenders. Some of us don’t mind doing a few small things instead of always taking the easy way out.

[4x4van]

Yes, stand-alone battery chargers, battery tenders, float chargers, etc are great...as are connectors, plugs, pigtails, hookup studs, etc...for a vehicle that doesn't already have a battery charger in it. What am I missing? :h

[Lynnmor]

Battery Tender has pigtails for their chargers. I have them on seasonal batteries and use them as needed.

I also made connection points from 1/2” diameter copper and #6 copper wire. I used 1/2” NPT PVC male pipe plugs drilled for the wire and 1/2” NPT PVC female pipe caps. This gives me a place to connect my 12 volt air compressor as well as large battery chargers.

[4x4van]

Why is everyone overthinking things? If all you want to do is keep the batteries charged and run the fridge on LPG (control board will use a small amount of 12v), run your 100' extension cord and plug your trailer into it using a 15A/30A adapter (available for about $5), and let the trailer's charger/converter do it's job. You won't be able to run microwave or Air Conditioner, but for what you want, it will work fine.

It's exactly what I have been doing for 28 years and 3 RVs during the week or 2 leading up to a trip, and even running the RV fridge on electric to pre-chill it.

A typical RV fridge uses less than 3 amps on 120VAC; and a 45A converter will only draw about 5A at peak charging.

[riven1950]

Thanks again folks. Looks like the following would work for what I was thinking about. Thinking I could use the 45 amp on the end of the pigtail and also a way to connect / disconnect my chargers alligator clips so I can charge my boat batteries with the alligator clips. What size fuse, if any would be good for the pigtail on the tt battery?

I would suggest these connectors.

120 amp connector.

I even use them so I can disconnect my battery from the trailer.

Or this one for charging only.

45 amp connector