Is 1ah load to small to hunt down?

[Blewett]

I had a trimetric on my last rig. Pretty sure it always pulled .2 or .3 amp when it was on. I had the kill switch between the battery and everything except the meter.

This way there was no chance anything can draw while the kill switch is in the off position. I have verified that with the display off there is less than .1 volt of amp draw from the meter. I would be curious what the amp draw is for the solar charger if it is not getting anything from the panels.

[chin_k]

The Mark 15 manual is here: https://www.chinookrvforum.com/viewtopic.php?t=2140

According to it here is the number that you want:

Current Consumption
Quiescent (Tare) Milliamps 8.8
Charging (with LED Bar-graph off) Milliamps 12.8
LED Bar-graph Milliamps per LED 5

So it depends on the setting. If there is no sun, it is drawing 8.8 mA, and you add 5 mA for each LED that it is driving.

[68camaro]

It appears I unknowingly found the .7 ah drain problem, but no idea how. Below is chronology of battery upgrade with charger.

First, installed lithium batteries on Thursday, reprogrammed the TriMetric battery monitor to set for lithium batteries per TriMetric suggested recharging parameters, these parameters are different than batteries data sheet so I will need to reprogram to match what manufacture wants.

Installed DC/DC charger with breaker. After install we reset the Power Center for lithium batteries to 14.56 volts to charge at battery manufacturers recommendation so as not to void warranty.

After test, I found in Store mode I was only losing between O and .1 ah, down from .7ah, so no complaints here. Not sure what change or upgrade solved this issue. With battery switch turned on, the battery drain was only like .3 ah, which appears to have been the lp and carbon monoxide alarms.

Chin, I removed the Mark 15 and replaced with TriMetetic several years ago.

[Scott]

The Mark 15 manual is here: https://www.chinookrvforum.com/viewtopic.php?t=2140

According to it here is the number that you want:

Current Consumption
Quiescent (Tare) Milliamps 8.8
Charging (with LED Bar-graph off) Milliamps 12.8
LED Bar-graph Milliamps per LED 5

So it depends on the setting. If there is no sun, it is drawing 8.8 mA, and you add 5 mA for each LED that it is driving.

How many watts would that be?

[chin_k]

Scott, W = A * V, so if the voltage of the battery is not complete full, and it only light up 7 LEDs, then the current will be 8.8+7*5 = 8.8+35=43.8 mA
Let's assume 7 LED means 12.1 V, then 43.8 mA * 12.1 V = 529.98mW or 0.53 W

[68camaro]

Is my math correct below, I am trying to find out how long it will to take to charge my coach batteries with the 30 amp DC/DC charger installed:

300ah battery bank
X 12v System
equals 3600 watt hours of battery total

So, with one 30 amp DC/DC charger will it take 10 hrs to charge? 30 amp charger x 12v = 360 watt hrs; so 3600 total battery bank watt hrs /360 DC charger max = 10 hrs?

If I add a second 30 amp DC/DC charger can I get the recharge time down to 5 hours using simple math?

Also, do people find battery monitor set to show Amps hours or Watt hours most useful?

[BobW9]

I do everything in amps and hours, never watts unless I'm trying to determine something related to an appliance. 300ah batteries becomes very simple, just your 30 amp charger times 10 hours, like you have.

I have my monitor usually either showing amps being used, or amp-hours down. If I'm not plugged in somewhere, then I keep it on amp-hours down, so a quick glance tells me if the batteries are getting low and I need to think about doing something special to get them charged up (e.g no sun, no shore, do I need to kick in the generator, or do I expect to leave soon and can charge while driving). I never bother with watts, as it really tells me nothing useful.

In theory, yes, two 30A chargers should halve the time to full charge from empty. But I'm not really sure what happens in real life when you have two chargers pumping up the voltage at the same time while they charge. Will they both stay in bulk/aborb the same, or will one go into float early, maybe? Possibly it might end up being 5.5-6 hours to full charge?

If you do end up getting another 30A charger, please let us know how it works out after you've gone through a few deep discharge/charge cycles.

[Scott]

If you have a 300ah bank and a 30 amp charger, then 10 hours would be the hypothetically correct time to charge from zero to 100%. But you probably won't be discharging a bank that size to zero, most likely, and I would be surprised if the DC-DC unit + alternator will push a consistent 30 amps (maybe it will, let us know!). There are other factors involved such as temperature, what your actual SOC is, etc. My advice is don't worry about it unless you plan to track down micro values in the half watt range as seen in the calculation a couple posts up. Again, adding a second DC-DC charger won't really help you here since the weak link is your alternator, and more specifically its ability to reject heat. For your last question: It's entirely personal. Generally I prefer watts because it accounts for both volts and amps, making it easier to grasp what an appliance is consuming or a charge device is producing. I like to think of state of charge simply as a percentage, like a fuel gauge (voltage alone is useless from a practicality standpoint).

[Blewett]

In theory, yes, two 30A chargers should halve the time to full charge from empty. But I'm not really sure what happens in real life when you have two chargers pumping up the voltage at the same time while they charge. Will they both stay in bulk/aborb the same, or will one go into float early, maybe? Possibly it might end up being 5.5-6 hours to full charge?

If you do end up getting another 30A charger, please let us know how it works out after you've gone through a few deep discharge/charge cycles.

This was my initial thought. I assume you are talking about charging it off your alternator. I believe the Dc-dc chargers have an amperage limit to protect the alternator from burning out.

[BobW9]

I was just thinking about having two chargers in parallel, wasn't really considering the B2B off the alternator part.

I actually have an upgraded 200 Amp alternator and a Sterling Power B2B charger, the "Pro Batt Ultra" BB1260, 60 Amp 12volt charger, with the optional Remote Control / Display.

URL for it is
https://www.sterling-power-usa.com/Ster ... arger.aspx