by resident_genius » Wed Jan 06, 2010 1:37 am
well, the whole system is getting re-done.
i re-worked my master kill box and now each cell has its own 0-5DCV, 0-25 ampere capable driver. so yes, my system is going to use 50 amps.
up front, by me, is the lighted LED master kill switch, 0-25 amp ammeter (total input amps shown here), fuse holder with warning light, and two knobs- the top knob controls cell #1 and bottom controls cell #2. a second box showing the amperes at the cells is going to be mounted in front of my glove box, so i can tell exactly what is going on all within arms reach. ill be able to monitor input amperage, and individual cell amperage.
ordered two 0-30A ammeters and shunts today from all electronics. these are the two going in front of the glove box.
the inner workings of my cells also got re-done. i ordered fazzio steel to laser cut me ten 316 SS 18 ga 4" by 5" plates. $8 a plate. not bad. holes and all, laser cut. booyah. each cell gets five plates. some SS allthread coming in from fastenal.
this should lower my working voltage even further.... i was pushing one of my cells @ 25 amperes with only 2.54 volts, compared to the 3.3V for 40 amps, but both cells. each plate has 4.5 x 4 of active surface area. so with five plates it'll be well within boyce's reccommendations for amperage. even room for expansion with a higher ampere driver! haha.
in the back is where i've got a larger box with single fan cooling both of the cell driver units. again, they are remote controlled via my front control box with adjustment pots. i've been putting many many coats of liquid electrical tape on the unit so theres no accidental shorting.
as you can see i've built up the traces as heavily as possible given the small space to work with. i really should have separated them. ohwell its not too late, if i run into problems i'll just put them on their own board.
well, its all about numbers now innit?! well, lets see here. datasheet from manufacturer says....@ 2.5 DCV output and 25 amps, at a 10 volt input, i'd be using 6.9 amps. but im closer to 14 volt input. so doubling that, thats a <15A input for 50 amps[output] driving my cells. and keep in mind, having my new plates should decrease my cells resistance, lowering voltage further! im guessing its going to be in the 10-12 amp range. prolly more towards ten. we'll see.