I have a Tundra and the "temperature compensating" was causing issues charging my AGM due to the constant low voltage. There are a lot of threads on the Tundra forums with people that have the same issue, some people were actually putting there truck on a charger every night to top the battery up. They ended up finding that Toyota use one of the fuses to detect the voltage that regulates the alternator output, they put a diode inline using an add-a-fuse holder to increase the voltage. I ended up buying a replacement fuse that had the diode in it to trick the alternator. A company in Australia makes a couple of models, two are a fixed voltage increase and the other has an adjustable voltage increase. I bought the adjustable one, but honestly I haven't changed it since I got it and the setting I ended up using I think is the same voltage increase as the non-adjustable ones. I was a little leary about ordering something from Australia, but it arrived almost 30 days later. Here is their website if your interested, https://www.hkbelect.com/products/toyota/?model=tundra&year=2012I tested this today. The alternator is a "temperature compensating" type. Initially voltage was 13.9V and dropped to 13.4V once the engine was nice and warm. I'll have to check the spec but I think that is normal.
I have a Tundra and the "temperature compensating" was causing issues charging my AGM due to the constant low voltage. There are a lot of threads on the Tundra forums with people that have the same issue, some people were actually putting there truck on a charger every night to top the battery up. They ended up finding that Toyota use one of the fuses to detect the voltage that regulates the alternator output, they put a diode inline using an add-a-fuse holder to increase the voltage. I ended up buying a replacement fuse that had the diode in it to trick the alternator. A company in Australia makes a couple of models, two are a fixed voltage increase and the other has an adjustable voltage increase. I bought the adjustable one, but honestly I haven't changed it since I got it and the setting I ended up using I think is the same voltage increase as the non-adjustable ones. I was a little leary about ordering something from Australia, but it arrived almost 30 days later. Here is their website if your interested, https://www.hkbelect.com/products/toyota/?model=tundra&year=2012
Well that's aggravating. I thought one of the reasons to use a DC-DC charger was to compensate for voltage drop between the power source and the target battery.My issue was too much of a voltage drop between the alternator and the DC-DC charger for the house battery because I was using 8awg wire, causing the charger to not produce full output. I did a test using 6awg and 4awg and the charger did produce full output. So the takeaway for me is to keep the voltage drop between the alternator and charger to under 3%.
Well that's aggravating. I thought one of the reasons to use a DC-DC charger was to compensate for voltage drop between the power source and the target battery.
Well that's aggravating. I thought one of the reasons to use a DC-DC charger was to compensate for voltage drop between the power source and the target battery.
Yes! Use #2 wire and connect directly to the starter battery, and the Orion will be happy. The starter battery acts like a big "spike-snubber", and its voltage will be relatively stable, so it's a good point to connect to IMHO (as opposed to wiring to the alternator). We use use an MRBF fuse right at the battery terminal.The charger can and does compensate for a lower input voltage (being a buck-boost converter), but it expects that input voltage to remain fairly constant over its range of output, hence the <3% voltage drop.