12 volt questions

[kb0zke]

1. Until this morning, every time I looked at the percent of charge it was near 100%. This morning, though, it was less, and was dropping during the day. When the sun came out around noon the charge started going back up. As soon as the sun set, though, it started heading back down. Currently (7:30 p.m.) it is at 73.3%. We are plugged into shore power, and various 120 V items are working, so I would think that I'm getting shore power. So why aren't the batteries (I have two Li batteries) charging? Isn't there a converter in here somewhere that is supposed to charge them? Where might it be hidden?

2. The cabinet under the sink is very dark, and it would be nice to have some light under there. Is there a source of electricity (preferably 12 volt) that I can easily tap into?

[jkwilson]

Check your battery disconnect switch and then the breaker panel first for a tripped breaker. Your converter is likely behind the breaker panel and I think you get to it through the hutch on your trailer.

[Hoopy Frood]

You say "Until this morning", but how long are we actually talking about? 1 day, 1 week, 1 month... Yes, you have a converter that will charge your batteries when plugged into shore power. First thing to do is to make sure your Battery Disconnect Switch has not been accidentally turned to "OFF". It happens sometimes. After that, check converter supply circuit breakers, and then the converter itself.

[SilentService]

1. Until this morning, every time I looked at the percent of charge it was near 100%. This morning, though, it was less, and was dropping during the day. When the sun came out around noon the charge started going back up. As soon as the sun set, though, it started heading back down. Currently (7:30 p.m.) it is at 73.3%. We are plugged into shore power, and various 120 V items are working, so I would think that I'm getting shore power. So why aren't the batteries (I have two Li batteries) charging? Isn't there a converter in here somewhere that is supposed to charge them? Where might it be hidden?

2. The cabinet under the sink is very dark, and it would be nice to have some light under there. Is there a source of electricity (preferably 12 volt) that I can easily tap into?

I will try to answer #2 first:
Typically your converter is located behind the false wall in your cargo bay near the water control panel. I'm curious if you changed out your converter to one that can charge lithium batteries at a higher voltage? most stock converters will charge them but only around 75% SOC. Also the cold will have some effect on the SOC. If that is the case, it may be the answer to question #1 .
I'm not an expert so hopefully someone else will chime in.

[kb0zke]

Looks like I have some things to check in the morning. To answer some of the questions above, we got the trailer Monday afternoon. We spent Monday night in it on the dealer's parking lot. Tuesday they fixed a few things, and we spent Tuesday night in a commercial campground a couple of blocks away. Wednesday we came home. Today (Thursday) is when I noticed the problem.

Tomorrow I'll go looking for the converter.

[SilentService]

Looks like I have some things to check in the morning. To answer some of the questions above, we got the trailer Monday afternoon. We spent Monday night in it on the dealer's parking lot. Tuesday they fixed a few things, and we spent Tuesday night in a commercial campground a couple of blocks away. Wednesday we came home. Today (Thursday) is when I noticed the problem.

Tomorrow I'll go looking for the converter.

We bought our then new trailer 6 years ago and I'm still learning. The only way to learn stuff is to research, ask questions on the forum, and jump in and start exploring your trailer. YouTube is a great resource as well. What helps us learn more is your response to your actual fix so keep us posted.

[SolarPoweredRV]

1. Until this morning, every time I looked at the percent of charge it was near 100%. This morning, though, it was less, and was dropping during the day. When the sun came out around noon the charge started going back up. As soon as the sun set, though, it started heading back down. Currently (7:30 p.m.) it is at 73.3%. We are plugged into shore power, and various 120 V items are working, so I would think that I'm getting shore power. So why aren't the batteries (I have two Li batteries) charging? Isn't there a converter in here somewhere that is supposed to charge them? Where might it be hidden?

2. The cabinet under the sink is very dark, and it would be nice to have some light under there. Is there a source of electricity (preferably 12 volt) that I can easily tap into?

I will try to answer #2 first:
Typically your converter is located behind the false wall in your cargo bay near the water control panel. I'm curious if you changed out your converter to one that can charge lithium batteries at a higher voltage? most stock converters will charge them but only around 75% SOC. Also the cold will have some effect on the SOC. If that is the case, it may be the answer to question #1 .
I'm not an expert so hopefully someone else will chime in.

I agree with SilentService's answer above.

When you are plugged into Shore power, your Converter should keep your batteries at 100% as well as provide all the power you need for your 12v lights and accessories.

Some newer coaches have an "auto sensing" Converter which will sense that you have Lithium batteries. However, the WFCO Converter that Grand Design uses has had problems with the "Auto Sensing" part and often reverts back into "Lead Acid" mode which may explain your 75% SOC (State of Charge).

I am assuming from your description that you also have a Solar system installed. Having Solar would explain why your batteries charged up to 100% later in the day. Your Converter is only able to maintain a 75% SOC and your Solar system is able to properly charge (top off) your batteries because your Solar Charge Controller is properly set for Lithium batteries.

If your Converter is not the auto sensing type, or you continue to have problems keeping it set to Lithium mode, I would recommend replacing it with a Converter from Progressive Dynamics, probably with one capable of charging at around 90 amps (OEM Conveters are usually 35 to 55 amps). This will allow you to charge your batteries almost twice as fast as the OEM (WFCO) Converter.

[SolarPoweredRV]

2. The cabinet under the sink is very dark, and it would be nice to have some light under there. Is there a source of electricity (preferably 12 volt) that I can easily tap into?

With regard to your dark/missing under cabinet lighting, you have two options, install 12v lights and find a power source, or you can find some battery operated lights that you could install. Some of the battery powered lights even have motion sensors for whenever you are working on the countertop.

[Redapple63]

1. Until this morning, every time I looked at the percent of charge it was near 100%. This morning, though, it was less, and was dropping during the day. When the sun came out around noon the charge started going back up. As soon as the sun set, though, it started heading back down. Currently (7:30 p.m.) it is at 73.3%. We are plugged into shore power, and various 120 V items are working, so I would think that I'm getting shore power. So why aren't the batteries (I have two Li batteries) charging? Isn't there a converter in here somewhere that is supposed to charge them? Where might it be hidden?

2. The cabinet under the sink is very dark, and it would be nice to have some light under there. Is there a source of electricity (preferably 12 volt) that I can easily tap into?

Hi David,

We have the same rig.

A couple of things for you to check.
1. Make sure the battery disconnect is turned off meaning it won’t s connected to the system and the converter can charge when plugged in.
2. Make sure you are getting voltage from shore power into your rig with a digital multimeter.
3. Check the ac circuit breaker for the converter to make sure it’s not tripped.
4. Your converter and a behind the grill for the little hutch. It takes about 8 screws and it’s there (picture attached). There are two fuses in the converter, make sure they are not blown.
5. Now that you have access to the converter measure the output voltage. In bulk charge mode for lead acid you should get approximately 13.6..



I hope this helps.

Bill

[huntindog]

The factory battery LED/percent of charge is just a volt meter. It doesn't work well with standard batteries, and is useless with lithium. A standard LA battery is fully charged at 12.8 volts. A lithium is fully charged at 14.5 volts. Your factory percent gauge will show 100% at 12.8 volts..... That is close to empty with a lithium battery. You need a lithium convertor, to properly charge your battery and a shunt style battery monitor to accuratly display it's state of charge.