Using volt meter to show battery status.

mgarr682

My boat has two batteries, a cranking battery (Interstate 24M-XHD) and a house battery (Interstate SRM-24) wired with a BEP VSR module. My engine is a BF90 with 35 amp alternator. The cranking battery is connected to a volt meter (standard Honda instrument) that comes on when the ignition is on, off when the key is turned off. I am considering adding a volt meter to check the status of the house battery periodically and was wondering if the marine battery monitors on the market are really worth the added expense over simple volt meter.

Any facts, opinions or thoughts on the issue are appreciated.

Sunbeam

BrentB · Posted: Fri Feb 08, 2013 2:21 pm Post subject:

Most folks say a meter has more advantages and low cost to install

Here is an useful article
http://www.pbase.com/mainecruising/battery_monitor

Grumpy · Posted: Fri Feb 08, 2013 2:31 pm Post subject:

I agree. I have found the Victron to be extremely easy to fit and it gives a much more detailed and correct indication of what is happening and how much charge you have left. Much better than simply reading voltage.

M

journey on · Posted: Fri Feb 08, 2013 2:45 pm Post subject:

Get a cheap panel voltmeter, put a 2 way switch behind it and mount it up by your helm. Wire it back to the batteries (hope you only have 2 ea.) so you can read the BATTERY voltage (not the PANEL voltage) and you're good to go.

Batteries being charged: 13-14 Vdc
Charged battery at rest: 12.6
battery at 50% discharge: 12.3
You get the idea.

Radio Shack has 0-15 Vdc for $13, P/N 2200036. Amazon has 0-20 Vdc for $9 (including shipping.) Do NOT get an automotive type.

The Victron is an integrating ammeter, probably includes the Pruess recharge factor and can operate as a voltmeter. While a great device and I'm envious, for C-Dory use a simple voltmeter is all one needs. We're not as cruising sailboat sailor who wants to run the diesel only when needed. Our outboard always is running when the boat is moving.

You're welcome, Boris

mgarr682 · Posted: Sat Feb 09, 2013 10:52 am Post subject: Thanks for the input.

My electrical needs aren't great as I don't use a lot of electrical devices when not underway. Mainly I want a way of checking the house battery before dropping the hook for the night to be sure the house battery has charged up enough through the day when the engine is run to power the anchor light, cabin lights for short periods and my single burner Wallas stove/heater over night without discharging the battery to the point that it's being damaged.

Over the long run I'll be switching incandescent light bulbs for LEDs which should make a big dent in the over night power load. My concern is that during the day when fishing I'll often only be running the engine for short periods or at low rpm's when trolling which may not give me enough of a recharge considering the devices that will be drawing current then (VHF, chart plotter, fish finder, cell phone charging, etc.).

I'm thinking I may just take along a hand held volt meter for checking the battery voltage to get an idea of its charge state and if that proves sufficient install a simple volt meter. If that doesn't give me a good enough indication of battery state then install one of the more expensive monitoring systems.

Thanks again for the input!