Hi Running Isolated 12|12V 30A charger from engine on 2007 Tacoma V5, specs say 130amp alternator, using Victron Smart BMV and smartsolar charger. This is a newer system so haven’t run the engine with the battery state much less than 94%. Today with the system at 73% At first the system showed 12 am into the battery, at this point solar panel was registering ~4amp out, then over the next hour driving constantly at hwy speed, it stair stepped down to about 1-2 amp from the battery charger. I checked this by turning off the solar. Voltage on the battery was never above 13.5 the whole time. And the DC charge was in bulk mode. I looked back to the previous day and a similar pattern appears. Any ideas what may be going on here?
The Orion could be getting hot and reducing current to regulate its temperature. Is it somewhere well ventilated or is it next to something warm.
The alternator output voltage could be falling as it warms up or regulates voltage down if it is a smart alternator and as the Orion input voltage falls it will regulate current down.
It could be voltage drop on the input, especially if you have a cheap resettable thermal breaker.
Show us a few screenshots of the status screen and your settings including engine shutdown.
Get your multimeter out to check start battery voltage when this occurs.
Thanks for your input. things are pointing to Alternator voltage drop as it warms up. This is an 07 Tacoma with 250k miles. Since I became aware of this I replaced the battery that was a couple years out of warranty and the symptoms continue. One other thing is I blew the 30amp fuse on the line out from the battery. Wiring to DC charger was installed by camper manufacturer. Pic of system attached. Also today after battery was installed system could not reach voltage to turn charger on. Temperature is around 80F here. Voltmeter applied to the battery was ~13.5 with engine running which agreed with info on Victron app. For some reason phone wont do screen shots but charger settings were default. So, would you agree the next step is to replace the alternator? Any more info you need?
Also uploading interior pics for input on setup for ventilation. And for fun a view of the camper. Note the opening to tiedown brackets is open for air flow. Cabin view is unloaded. When packed with gear charger corner area will have gear around it but will be open at the top. Thinking about adding a little fan down there.
Thanks for all your input
Install location looks OK as long as air can het down to the bottom and then back up but these units do get hot. A 30A fuse is too small, the max output is 30A, the input will be higher due to conversion losses and voltage boost. The manual recommends 60A. See link st bottom. Also see if your wiring is large enough, this needs sizing on voltage drop not amp capacity rating. And while you are there check connections for corrosion. I agree, get the alternator checked at a vehicle electric shop.
So after a bit of digging I found that the '07 tacoma has something like a smart alternator that will drop the voltage to ~ 13.2-13.5 after the engine has warmed up. Reading through the smart alternator settings it seems like those just keep the charger on if voltage drops very low. Is that the case? Or will it make the alternator kick out more volts? It does send 14 volts when the engine is cold. My wiring is 10guage over 16ft so that is another factor that decreases the amps received. Was hoping to get at least 2 -3 amps off the engine. Any tips how I might make the alternator kick out more juice?
You can reduce the cut-off voltage from13.2V to 12.9V in the Orion when recognising the motor. If the alternator actually only regulates to 13.2V, this should be sufficient. If it regulates down even further, you can go even lower. However, you must then also set the cut-off voltage of the Orion to 0.1V less than the motor cut-off voltage. In this case, however, it is advisable to switch off the Orion via D+.
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