SiO2 Batteries and High Amp Draws

pianotuna wrote:
High draw on LiFePo4 is limited by the battery management system. It depends on what the maker sets it at. Anyone know what is most common? 100 amps (1c)???

Seeing as my goal is a battery bank of at least 400 and possibly 700 amp-hours, the speed of charging of Li is not useful to me--as my fastest charger maxes out at 127 amps @ nominal 12 volts.

Efficiency also does not concern me as I want to float the batteries between trips. SiO2 float nicely. Li, not so much.

For me, the most important factor is full charging not required on each cycle. My understanding is that both Li and SiO2 are quite happy, if they are fully recharged once every 30 days.

1C seams to be the most common set up on a 100Ah battery. in your 200ah single batteries yoyu se 100, 125, 150 depending on who makes it. the way to get around it is to build your setup like you would in a normal setup. if you want 400AH of storage use two 200AH batteries or four 100AH batteries . if you go the later you can have a 400Amp draw, the first anywhere from a 200 to a 300Amp draw. in the camper I did a single 300ah battery and I used a 125amp draw BMS but I have nothing tht takes anywhere near that, I think if I leave my water pump runing ll my lights on the furnace on and the fridge on 12V I might be drawing 18amps... but I did build it so I could add a microwave later if the wife wants one and a small one is about 80amps i believe. in the 5th wheel when I get that set up I will be building three of what I have in the camper so 900AH capacity which will give me a draw capability of 375Amps which is more than enough to handle my 2000 watt inverter. there are BMS that have capabilitied of 250amp draws and such but I felt that even using a 1C discharge rate was likda useless on any battery, like look I can do a big draw, but my battery is dead in one hour.... the draw with out the ability to sustain it to me is useless, but ya I can see where the capability for shirt bursts would be desiriable.

I also float mine and they seam to like it with no issues so far, but I do float at a voltage that would indicte a charge level of 90%, so I bring them up to 100 on a full charge voltage then the float kicks in and they taper to 90% it all depends on your gol. if you want to get the absolute most lige say 7-8000 cycles then ya you have to jump through some hoops but if you want to get just the advertised 3000 ish then there pretty good to go and easy to manage. the issue your going to have is cold weather and where the batteries are. it is easy to get the 700+ AH requirment but what level of discharge do you need? this will tell you how many different 4 cell batteries you need to build and what kinda BMS you need.

Steve