Trimetric owners: how many AH does it take to...

My philosophy of using a battery monitor is that it has one task, and that is to keep the batteries above 50% SOC (state of charge). Our situation is different and I am using a Victron rather than Trimetric. It is set to display SOC any other function may be entertaining but...

I use a three meter homemade DC MONITOR that monitors the DC VOLTAGE of my two selected BATTERY groups and the total DC CURRENT being pulled from the two selected Battery groups. The DC CURRENT meter also shows me how many DC AMPs is being demanded from the on-board Converter/Charger unit when charging the selected battery groups.



This is wired into my DC SYSTEM like this...


The only thing I would gain by using the TRIMETRIC model would be the settable DC ALARM when the DC VOLTAGE would drop to a particular DC Level. Presently I have to watch the DC MONITORING panel to determine when it is approaching 12.0VDC when being used.

My DC MONITOR PANEL only provides me information as to the status of my battery groups so that I will not let them get below their approximately 50% charge state. When I see 12.0VDC on the selected Battery Group I will stop using the batteries until I get them charged back up to their 90% charge state.

In my case this is all planned to happen around 8Am each morning when I am allowed to run my 2KW Honda Generator. Most all of the places we go to has generator run-time restrictions in place...

Roy Ken

If you have deep pockets and do not camp in the cold consider LI chemistry batteries rather than lead acid.

I am not a fan of amp hour counters, with the exception of the smartgauge because all the others drift out of calibration whereas the smartgauge gets more accurate over time.

Hi,

I have a motorhome, and the jacks draw about 40 amps for only a few seconds to level it, so if run a full minute at 40 amps draw, it would still be less than 1 amp hour.

The pump draws about 7 amps per hour, while pumping 2 GPM or 120 gallons. So water pump is also insignificant. (unless you have a 120 gallon tank, then it would be about 2 AH per day)

What really consumes the power is the refrigerator, CO meter and propane leak detector. Together they draw 0.8 amps and 1.2 amps while the refrigerator is on. This works out to about 35 AH daily.

If you are really concerned about the amp draw while loading the camper, try to plug it into the truck for as much time as possible, and the alternator will supply all the power, and charge the battery slowly at the same time.

Chances are that the truck to camper battery wire is really tiny. Maybe #12 wire? Perhaps #14 wire? Upgrading to #8 wire and a twistlock 30 amp power plug (so it will not accidentally get connected to household power) will allow the alternator to fully charge those large golf cart batteries in less than a 5 hour drive. With #12 wire, the amp might move at 12 - 15 amps per hour, or a 10 hour drive can take them from 30% state of charge up to around 70% full. 10 HOURS!.

My real recommendation is to install some solar panels. A pair of 140 watt solar panels will put out 8 amps to the batteries several hours per day, figure each one will put back about 40 AH daily with a PWM controller. Don't expect a lot more with the much more expensive MPPT controller, the amps back into the battery will only be about 5% more per day.

With the solar panels, all trips will start out with full batteries, and you might use say 100 AH daily. Instead of discharging them over 2 days, you will take out 100 AH, put back 40 - 80, then take out 100 AH, and put back 40 - 80. You can keep doing this for several days before needing to run a generator.

Another thing to help heat the camper is a Olympic Catalytic heater. It does not consume any 12 volt power, but you do need to leave a roof vent and kitchen window open a bit, just like when you are cooking with the stove.

Have fun camping!

Fred.

pianotuna wrote:
If you have deep pockets and do not camp in the cold consider LI chemistry batteries rather than lead acid.

I am not a fan of amp hour counters, with the exception of the smartgauge because all the others drift out of calibration whereas the smartgauge gets more accurate over time.

Is this the meter that you prefer:

http://www.defender.com/product3.jsp?path=-1%7C328%7C2289954%7C2289950&id=2388351

Thanks

Hi,

Yes.

TheCabin wrote:

pianotuna wrote:
If you have deep pockets and do not camp in the cold consider LI chemistry batteries rather than lead acid.

I am not a fan of amp hour counters, with the exception of the smartgauge because all the others drift out of calibration whereas the smartgauge gets more accurate over time.

Is this the meter that you prefer:

http://www.defender.com/product3.jsp?path=-1%7C328%7C2289954%7C2289950&id=2388351

Thanks

My family of four lives in our TC full time and it is my opinion that having a battery SOC meter is an indispensable tool... I wouldn't be without one! The model I have chosen is the TriMetric 2025-RV.

i don't much care about your example of the energy used to operate the jacks to load the TC into the truck (no offense intended!). This is because shortly after the loading the TC I would most likely be starting the truck's engine... and my alternator replenishes the energy used very very quickly.

However, I do pay attention to the power we use at night while the solar panels are sleeping; My DC fridge consumes 40-50 Amp-hours between sunset and sunrise, and I usually make water for my coffee and the kids' oatmeal in the microwave early in the morning which is another 10A/h. Then I watch the battery SOC slowly creep back up to 100%... or not, depending upon weather conditions.

I have used the TriMetric's data output to log some specific discharge and charge characteristics, but for me battery monitoring isn't about tracking how much power any individual appliance is using, rather it gives me a general idea of my total energy sue and the status of my battery bank. Most importantly, it provides me with a good indicator of if I can simply let the solar do it job... or if I need to think about firing up the generator or starting the truck.

Hope this helps.
Cheers
-Mark

I am with Mark.
any loading electric cost is put back in batteries by truck charging system.
I guess if you unload at a boondock site it would cost electric.

also since I already decided on the Bogart I used there controller for the solar system. it integrates with the TriMetric and allow precise control of voltages while charging from solar. Plus you can go into the unit to program what type of batteries you have so it knows how to charge. I wish the TriMetric could control the voltage of the onboard charge system, but I only use that while campground camping. sitting at home my 200w solar system keeps the two 90ah AGM's fully charged without plugging it in.

as far as charging time (per AH) this changes with sun angles, cloud covers, etc.

Do the meters mentioned measure the condition due to age of my batteries? I have a Trimetic, it shows the solar panels voltage coming up from my panels, voltage after the batteries are charged and
as they go down while being used etc.

This all looked normal but I noted as the batteries aged, even though the meters showed normal after charging they seemed to run out of
power more quickly with the same appliances being used.

Is there anyway to tell the condition of the battery as it changes from new to more aged...


The only way I could tell was when the fridge would not run all night
and it did so easily when they were new.

I changed the batteries to new and all seemed well, now I have to wait
to see how long they last, meters or no meters???

RoyB: where, may I ask, did you purchase your digital voltage read-out's?