Need recommendation for house battery monitor/status meter

[brophyl]

I have a 1991 Sportsmobile, Dodge Ram Van, penthouse style. The house battery is a Trojan SCS225 house battery, 130Ah, which tests out great and has been serving fairly well. The built-in charger/converter for the house battery is not a "smart charger" so to charge it, I've been removing the sofa and the battery cover to attach a freestanding smart charger (Schumacher SSC-1000A). It's a big job (hard to remove sofa, hard to work with the battery cover which has 4 screws that are easy to drop and hard to retrieve) and I'd like to avoid it.



The only battery meter I have (other than the freestanding smart charger’s) is a simple status meter (maybe provided with the van?) that plugs into the cigarette lighter in the house. It has red, green and striped white/green sections. The meter gives no numeric information about input or output voltage or percent charge, and it seems to be really inaccurate. The “charging system” never displays anything above the red “low” section, even when charged into 110V power. After fully charging the battery to 100% using the smart charger, this little meter registers “low” (red) in the “battery” section. During a weekend camping, it seems to randomly move between red and green striped sections rather than steadily dropping. The meter doesn’t register any increase in battery status after hours of driving (which should completely recharge the battery, I believe).



I'd really like to have more information than this little meter shows -- like a numeric display showing percent charge for the battery, input voltage, output voltage and maybe an estimate of how much time is left on the battery before it needs recharging. (Pardon if I'm not using correct terminology -- I'm no electrician...). I know there are lots of meters out there with a big range of prices & complexity but just have a couple brief Qs:

Can a digital battery meter plugged into the cigarette lighter in the house provide accurate information on battery percent charge, input voltage and output voltage, and remaining time? Or does the meter need to hook up directly to the battery itself to provide this information?

Can someone recommend a relatively simple battery monitor for a non-solar system, one battery, not very technical user? I did review the topic "looking for new/upgraded voltmeter" (viewtopic.php?f=40&t=1894&hilit=battery+meter&star t=0) but the installations look too difficult for me, plus most of the links to voltmeters are defunct. I guess I could have a local shop install the meter if I knew which was the best one for my purposes.

Thanks to anyone who can help!

[Viejo]

You don't need to connect directly to the battery for metering, the cig lighter outlet works just fine.
I've been having good luck with this meter I found on Amazon...

http://www.amazon.com/gp/product/B000EV ... 00_s00_i00

This meter will tell you the input voltage while on charge and the output voltage while under load.
As for percent charge remaining, use this chart...

% charge | Voltage
100 12.70
95 12.64
90 12.58
85 12.52
80 12.46
75 12.40
70 12.36
65 12.32
60 12.28
55 12.24
50 12.20
40 12.12
30 12.04
20 11.98
10 11.94

I have that chart taped to the wall under my meter.

No meter can show time remaining because the load varies as appliances and lights are turned on and off. That is also the reason you analog meter seems to be erratic. For instance, when my refrigerator comes on the voltage drops and when it shuts off the voltage comes back up a bit.

You should use only the top 50% of your capacity and if you do draw the battery lower than about 12.1v, recharge it ASAP. Drawing down a battery and leaving it down is the quickest way to kill it.

To quickly go from novice to expert on 12v systems, read this page - The 12 volt side of life.

http://www.marxrv.com/12volt/12volt.htm

The site is down today and if it's down permanently I sure hope someone has grabbed the content.

Your charging method needs improvement but I'm not qualified to advise you on that.

[Ultrasport12]

I have the same meter as Viejo. I also got it from Amazon. It works great for me. Its a modern version of the one you have.

I too think it might be time for a new charger at the least. A lot has changed in the past twenty years with battery charger technology. With a newer unit that has three step charging you can just plug it in and forget about it, no over charging ever.

If you dont need an inverter you could just buy a new charger.
I think you could still use your old inverter if you wanted to.
Or get one of each an inverter and a charger.
Or just get a newer combination unit.
Everything today is more efficient in creating and using power plus much easier on your batteries and electronics.
Other benefits are smaller, lighter, running cooler and quiter.

...Jamie

[brophyl]

Thanks so much, Viejo and Ultrasport12. Ultrasport12, you mentioned I could just install a new charger if my existing inverter is good... I think it's probably fine since we had the whole electrical system checked out and they said "everything's working fine." So... do you have a specific recommendation for a charger? Do you think it would fit in the existing space under the sofa? I guess it would be wired in between the existing converter/charger and the battery? I'd probably have it professionally installed to make sure the wiring is done right, unless it's really simple.

[LenS]

I have an inexpensive digital voltmeter hard wired into my house battery and the meter is mounted on a van wall. $6. Meets my needs. Got the volt meter at Micro Center.

[Viva]

I recently bought a Victron BMV600S. This type of monitor gives good information on a battery/bank. I've used similar (but different brand) ones in years past, but chose the Victron this time around because I like the "plug and play" wire leading to the display and (other models you have to make more wiring connections and there is no "plug") and it got good reviews from people whose experience I trust. They cost ~$150.

You can see details here:

http://www.victronenergy.com/battery...nd%20bmv-602s/

[larrie]

Originally Posted by Viva

I recently bought a Victron BMV600S.

I also am using on of the Victrons and am very pleased with it. It is very easy to install. Hook the house battery ground to one side of the the included shunt, the house electrical panel ground to the other side of the shunt and the power wire from the shunt to the positive side of the house battery. Then plug in the six wire phone cord into the shunt and the meter and you are ready to read volts, amps being used, etc.

[Ultrasport12]

Originally Posted by larrie

I also am using on of the Victrons and am very pleased with it. It is very easy to install. Hook the house battery ground to one side of the the included shunt, the house electrical panel ground to the other side of the shunt and the power wire from the shunt to the positive side of the house battery. Then plug in the six wire phone cord into the shunt and the meter and you are ready to read volts, amps being used, etc.

Hey larrie what kind of charger did you just install that might work for bropyle.
How do you like your BMV600S?
Did you look at any other brands?
Did you find a solar panel yet?

I dont know what kind of onboard charger I would use these days, I have solar and don't need to charge anymore. Before I installed the solar panel I alwayed used this charger but its not an on board unit.

http://www.amazon.com/Black-Decker-VEC1 ... ry+charger

We used them at work for years even when they were called Vector before Black and Decker bough them out and they were great. My home unit is three years old and works great.

I the past I have always used Guest boat chargers with good results so I would use one of them I guess. I was going to do an onboard chager but now I guess I dont need to.

Here are some available from Amazon.

http://www.amazon.com/s/ref=sr_nr_scat_ ... a54e2684cb

Chargers are easy to hook up just one wire to positive and one to ground. Since you already have and inverter charger you can just hook it to the big cables on that I would think. You only need a single bank unit unless you want to charge the starting battery at tthe same time.

I hope that helps...
...Jamie

[daveb]

Originally Posted by brophyl

I have a 1991 Sportsmobile, Dodge Ram Van, penthouse style. The house battery is a Trojan SCS225 house battery, 130Ah, which tests out great
Can someone recommend a relatively simple battery monitor for a non-solar system, one battery, not very technical user? Thanks to anyone who can help!

High end battery monitors can be installed quite easily. Expensive but there are good ones out there. This Xantrex monitor has a link to the installation instructions. They do have added capabilities you're looking for. That said they are "more technical" to use than a standard voltmeter. You can google for info about them.

http://www.xantrex.com/power-products/p ... nitor.aspx


You claim the battery tests out great but it almost sounds like your isn't up to par. It looks like you have a standard wet cell deep cycle battery. Did you use a hydrometer on each cell and have you done a true load test? Battery sulfation can make a battery fail to take a full charge that should be exposed during the correct test. Even a battery with a 70% life left will seem OK if your load usage is minimal.

If the battery is good, and the monitor you're using is faulty, that might be a reason it's jumping around or there might be a poor connection between where you plug in the tester and the battery.

I also see you are using a 1000A charger. Batteries, especially a small wet cell battery like you have can be damaged by high amp charging. A long low amp charge won't buckle the plates like a high amp charge can. Myself, I would rather charge a single battery like you have longer at 5 amps rather than a quick 12 amps but would never charge at a higher rate than that. That is where a good 3 or 4 stage charger is worth the investment.

Hopefully your battery is good and you find a voltmeter that suits you. Even a good handheld voltmeter will work fine. Good luck.

Dave

[larrie]

Originally Posted by Ultrasport12

Hey larrie what kind of charger did you just install that might work for bropyle.
How do you like your BMV600S?
Did you look at any other brands?
Did you find a solar panel yet?

Jamie,

The inverter/charger I got is a 30 amp WFCO Ultra II. It is a three stage charger (absorption, bulk and float). Seems to be working very well. I looked at some other brands but this one seemed to match up best to the unit that failed. Plus it has space for three 120v breakers. Am strictly 12V with no inverter.

The BMV600S is nice. Very simple to install and less expensive that the Xantrex. It allows me to read volts, instantaneous current, consumed energy, state of charge, and time to go. It also has an alarm feature. I need to post write up on the install.

Ah solar. I have the components picked out and just need to find the time to see if there is someone local where I can purchase them. You would think that with the State of Oregon pushing solar as the great solution to the worlds problems there would be more locations to purchase the components. The other thing that is holding me back is the penthouse top bolts. They need to come off so I can run the wires through the canvas/penthouse interface. Am waiting for Gooseberry to go into production on his tee nut solution.