nctacoma
nj
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Joined: 02/20/2010
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Hi all,
Bought 2 new agm batteries and a new converter from bestconverter.com
Now I want to know when I need to think about charging them while camping. I would love to have a little battery meter that is hard-wired into my camper that has an alarm that goes off somehow to tell me when the batteries are about to reach their 50% limit and I need to turn on the generator.
I know about the volt-minder which seems like a great little unit for a great price.
I would like to be educated about other options as well.
thanks in advance
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jauguston
Bellingham, WA
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I bought this little meter on E-bay. They are always there. About $15.00. I put a switch above it. It is 0-20vdc
Jim
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skipbee
Glen Arm,Md. 21057 USA
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I use a digital meter that plugs into a lighter receptical. When it shows 12.2 volts I recharge somehow. It would be good to find one with an alarm that could be set to warn of this voltage. I installed the receptical with a short run to the batteries.
skipbee
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All that glitters is not gold. All who wander are not lost. See us on YouTube" Living the Lance Life" 3 of 4.
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jauguston
Bellingham, WA
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I bought this little meter on E-bay. They are always there. About $15.00. I put a switch above it. It is 0-20vdc
Jim
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Raften
Northern Calfornia
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Joined: 01/27/2003
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skipbee wrote:I use a digital meter that plugs into a lighter receptical. When it shows 12.2 volts I recharge somehow. It would be good to find one with an alarm that could be set to warn of this voltage. I installed the receptical with a short run to the batteries.
There is one with an alarm, BigFootFord can tell you the name as I don't recall it, around $25 or $30.
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SJR
Philadelphia, PA
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Joined: 11/07/2003
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Looking at these meters on eBay they have 4 wire connections - 2 for voltage and 2 for power. How do you connect them? I would think that only 2 wires are needed to connect to the battery. What am I missing.
Stephan
2010 Dodge 2500 Crew Cab
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bobndot
NY
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This is a popular unit . 2020 or 2025 . http://www.bogartengineering.com/products/TriMetric
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bigfootford
Fair Oaks, California
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Raften wrote:skipbee wrote:I use a digital meter that plugs into a lighter receptical. When it shows 12.2 volts I recharge somehow. It would be good to find one with an alarm that could be set to warn of this voltage. I installed the receptical with a short run to the batteries.
There is one with an alarm, BigFootFord can tell you the name as I don't recall it, around $25 or $30.
Here ya go...Good old Bestconverter's got it....I have one...
Bestconverter's Voltminder
2000 2500 9.6 Bigfoot,94 F250, Vision 19.5, Mich 245/70XDS2's, Bilstein shocks, air bags/pump, EU2000, PD 9260,Lifeline 100ah, 200W. solar, Morningstar Sunsaver 15A/ display panel, Trimetric, Delorme/laptop, Holux gps rec,led lights, Wave-3 heat.
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bigfootford
Fair Oaks, California
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nctacoma wrote:Hi all,
Bought 2 new agm batteries and a new converter from bestconverter.com
Now I want to know when I need to think about charging them while camping. I would love to have a little battery meter that is hard-wired into my camper that has an alarm that goes off somehow to tell me when the batteries are about to reach their 50% limit and I need to turn on the generator.
I know about the volt-minder which seems like a great little unit for a great price.
I would like to be educated about other options as well.
thanks in advance
Good for you. Take good care of those AGM's!!! I would not regularly discharge to 50%...I would do between 30-40%...Which is 60% to 70% full. (State of Charge SOC).
If you have spent the $ for all that you should invest in a Trimetric meter from Randy.....Then there will be no guess work.
If you set an alarm at 12.2 and you use your jacks your alarm may go off because your battery voltage drops with a load and recovers/goes up after the load goes away...
Here is a little chart to get you started with understanding your AGM's voltage levels, they are different than the Flooded wet cell batteries.
From this link: Lifeline charging procedure
SOC (%) vs. OCV
the battery State Of Charge vs battery's Open Circuit Voltage
An easy method to estimate the State of Charge (SOC) of the battery is by measuring its Open Circuit Voltage (OCV). This measurement should be made after the battery has been at rest for a minimum of four hours with the battery shut off from its charging source and load. The voltage is listed as Volts/cell and for a 12V (6 cell) battery at 25°C (77°F).
State of Charge (%) OCV per 12V battery
100 13.0 or greater
75 12.6
50 12.2
25 11.8
0 11.4 or less
Enough confusion for now?
Jim
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skipbee
Glen Arm,Md. 21057 USA
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Hi Ya bigfootford,
Thanks for the heads up. I can see the problem with the alarm and a big 12 volt draw. I'll stick with my simple little system, I've never had a problem in 7 years. I had a Trimetic type system on our sailing yacht where we had a lot of navigation, radio and refrigeration gear, I just can't justify the expense for what I think is more of a toy that a needed tool. I did install a remote starter for the diesel when we went to Alaska so that I could fire 'er up in the morning if needed but I never had to use it. I have never had dead batteries,ever. We usually do start the generator in the morning, when boondocking, to make coffee, and let it bring the batteries up.
* This post was
edited 09/28/10 07:24am by skipbee *
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