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| Remote Diagnostic - Battery - Sept 2021 |
Monitoring a vehicle which is parked off the grid
When I purchased the Roadtrek 210P I stored it at a commercial lot a few miles away. This was necessary because it could not fit in my garage and the Homeowner's Association I lived in had a rule which prohibits RVs on the property.
I investigated several options and decided to purchase a HUM which is owned by Verizon. This included a OBD transmitter to monitor the vehicle and a "black box" which transmits the information to me via the cellular telephone network. It does include vehicle location monitoring, too
To replace power drained by the onboard vehicle computer I was using a small solar panel placed on the dashboard. This proved to be inadequate with HUM upgrades which increased monitoring frequency transmissions. So I upgraded to a 30W solar panel with built-in controller. The new panel was able to keep the battery level up and I seldom got a "battery voltage" alert.
However, with the vehicle battery approaching 9 years of age, the battery would not hold a charge. This resulted in a 12V battery voltage while the solar panel was in the sun. At night the vehicle battery voltage began dropping off. A couple of weeks ago the battery died and the low voltage declined to about 10.5 Volts. Oh, Oh! That's a dead battery. I received several days of alerts and I replaced the battery. I received the alerts because in sun, the solar provided sufficient power to get the battery to about 12.3 VDC, but that is too low a voltage to properly recharge the battery.
There was no indication of an unusual load, but I disabled (turned off) the Battery Separator to be certain it wasn't cycling or powering up. My Roadtrek has two solar panel systems; one for the vehicle battery and another for the coach batteries. So there is no need to connect the two when the vehicle is stored and stationary.
As can be seen in the photo above, the battery voltage is reported as "stable" and during full sun the battery voltage while charging reaches about 13.5VDC. On cloudy days the voltage decreases to about 13.2 VDC. The vehicle was in use until September 14. It has been stationary and off the grid since September 15. The chart above shows the battery voltage during solar charge and also during nighttime. The vehicle is pointed easterly and the solar panel gets direct sun in late morning to early afternoon, if it is a cloudless day. The 12.82 VDC reading above was taken as the sun was rising but obscured by a building to the east. Some solar energy was available, but not full sun.
Overnight the vehicle battery voltage, with no solar available is about 12.75VDC, just before dawn (typical reading 7:00am). A fully charged 12V lead-acid vehicle battery is in the range of 12.5 to 12.7 VDC.
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