Home battery on Jeanneau 795 nc

[sasha]

Hello and happy to be here. We just got a brand new Jeanneau 795 nc and we have many questions.
So far, we are learning hard way 😂, but I hope to get some answers here.
On our first trip, the home battery has died and , of course garmin, bow thrusters and other stuff went off.
We had to go to some marina and get it charge with the included marine power cord.
Here are come my first two questions:

1. How to see (on Garmin??) the current status of the home battery?

2. Is the home battery supposed to get charged from the engine battery?

If yes, then how and why this didn’t work for us?

Appreciate any help ❤️

[rene460]

Hi Sasha,

Welcome to the forum, and congratulations on your purchase. You have many years of fun filled adventures ahead.

You will find many friendly like minded people here, and a wealth of valuable information in the archives, well worth browsing in your reading time. The search function works well on the forum and separate boards. Remember that many systems are similar across the model range, so don’t limit your searches to your particular model.

On your specific questions, first, the easiest way to check the battery voltage is with a digital voltmeter, use it to measure the voltage at the battery terminals. You can also buy self contained voltage displays that plug into the 12 V outlets on your boat (and car). Your Garmin instruments may have an option to read the voltage at the instrument terminals but I am not familiar with the Garmin instruments, I hope some other forum members will join in with more information. My Raymarine instruments do have a function to display the voltage at its terminals and Garmin may have similar. Just be aware that there are a number of reasons that this is not an accurate indication of battery voltage.

Second, most of our boats are supplied with a relay that connects the house battery to the engine battery when the engine is running. This means that the engine does charge both batteries, providing it runs at sufficient rpm for sufficient time, but the house loads do not flatten the engine battery when you stop, thus preventing you starting the engine.  I expect yours is similar.  It is not recommended that you make a practice of running the engine specifically for battery charging, but it can get you out of a hole if absolutely necessary.

On your specific issue, a likely cause is running the fridge overnight, along with your other loads such as lighting and instruments, and not running the engine long enough during the day to recharge the batteries, however to diagnose the problem more information is required.

Could you please tell us what house battery capacity you have, and whether your document package includes a copy of the electrical schematics? Also can you tell us about your cruise and whether my suggestion looks likely. Many of us get caught out by this one early on, but once understood there are some logical solutions that are relatively easy to implement.

Rene460