Originally Posted by senormechanico
I must be a caveman using LiFePo4
I leave my solar
on all the time (440 watts).
I leave the fridge on all the time (insulated with Aerogel).
I leave my ultrasonic barnacle system running all the time (average 800 ma).
I leave the LED backlight for my MPPT
controller on all the time (mounted in the companionway
steps which makes a great stair nightlight).
I leave indivdual LED cell voltmeters running all the time (under companionway
steps adding to stair nightlight and readable from the V berth).
Total draw average? I really don't know exactly. Maybe 1.5 amps or more, but the 200 aH battery
bank hits float almost every day. 13.8 bulk, 13.8 absorb time zero, 13.2 float.
CleanPowerAuto BMS just sits there doing nada but insurance
This is at the dock
, unplugged for months at a time.
When we're cruising, we have lots of electrical
stuff to use power including radar
, computer, wife's 1650 watt hair dryer, VitaMix (1400 watts for daily smoothies) and an ElectroScan every time we flush.
We never take a shorepower cord, it's just extra weight.
Never a problem for several years.
Are you guys really worried about 5 milliamps?
I actually agree with you on this. I want to use the Blue Sea switch, rather than just an EV200 or equivalent contactor, not because of any millamps saved, but to have the capability to manually switch it and to manually override it at the switch if any of the electronics
fail. I expect (or hope rather) that the HP BMS will work flawlessly forever (not) and I will never have an issue related to it.
I do plan (and hope) that my charger
settings will stop any overcharging (like you do). One of my criteria is whether the Admiral can understand how to use the dadgum system to have battery
power even under emergency
situations. Some of the designs don't do that IMHO.
My complexity has been, admittedly, in reaction to all the discussions of how the system can fail and kill the cells. By far the biggest investment I will have is in the cells. The rest of this complexity is fun in a way to put together for now but complexity is terrible on a sailboat especially while cruising offshore
which is our intention. I plan to install everything with the possibility to wire around the contactors or use them independent of the BMS and just hope that everything else works as advertised.
You and some others who don't bother with all this and have actual experience with it, and it is working fine, give me a lot of comfort that my investment will work as I need it. So my backup is to just remove (in place) the BMS involvement if need be, such as if it fails and I still need to use the boat (a very nice concept).
A question though: You say your BMS is just insurance
. Does that mean you have installed it in its simplest form (relays driving contactors)?
Thanks for your comments. Right now I am trying to be an information sponge before I actually put anything together. I still don't have cells in hand and my recent surgery will delay any installation
for at least a couple or more months. And since I like the intellectual exercise it doesn't bother me if I scrap half of my current
design before I put something in. At least that is what I have consciously decided to do. I have the time and would rather do this than cut grass. Of course I'd rather be sailing but that has to wait too. I am doing several big boat projects in the background and having fun with those too. I did this before - spend time putting together systems that work without constant twiddling after going offshore
. It worked. And the Admiral loved to keep track of the batteries via DC monitors, which will always, always be powered up even when I am not on the boat.