i run over 150 li-ions in parellel, and because of the low cut-off and charging cutoff, and the li-ion charge alogrythm (with the voltage max as opposed to v-drop)
and they act like one big battery, but on that, none of the batts are ever hit hard in discharge or charge.
Even with fat copper connections, i can crack it open and there will be tiny variances in voltages, due to tiny resistance differences between items. but the load and the charge are very small to the whole.
what your doing here is pulling full power out of each one. what is the protection?
see the stacked design though does add issues,
just that small ammount of resistance of the wiring can be a big difference in large amp situations. so when some wires longer than others, even if it dont add up to .001ohm of resistance total, the load on one battery can be Much higher than the others.
(this has nothing to do with series, were talking stacked parellel from what i understand)
so one battery goes down faster , as the huge load is stopped, the high batteries will equalise (cross charge) the low ones.
You already dont want the offset Loading to begin with, have that perfect first even if you use diodes.
i always say dont Chain connection, prefer to 'center connect"
augg did better picture before
|-load-|
|-{ ]-|
|-{ ]-|
|-{ ]-|
see last battery further away by leetel bits, little bits of wire that can make bigger differnces than you would think at high amp loads.
if instead you can run the exact same length of wire to each cell, even if it is unnessisary addition to the short lenght ones.
then the amp draw off each will be similar in resistance, then you have to check the cells every once in a while to make sure all 3 are working and taking part of the load.
myself i would do that, so the resistance of the wire is exactly the same, and would not use diodes. diodes are also one-way, so you would have to choose the way, charge or discharge.
Then i would use good cells (thats a given) then i would check the cells often, then i would have Protection, even on the whole set.
You can doubble up protection for a big parellel pack, took me while to get it working, till i got the resistance same EXACT and minimal, you can use multiple cheaper protections to get to large amps, and still have voltage cutoffs at both ends.
but with your design potentially you could still protect Each cell item, as you bring them up from the base to a central location (with the exact same resistance).
after i did all that stuff, i would not use the diodes. I can see the total reasoning for them, even mabey to add in a purposfull voltage reductions, i would just go the other way and insure i dont need them.
cheap protection can be aquired that does full 4amps (or overrated at 8) with those culminating prior to the load, if you got a big offset or lesser battery, the protection would kick in and tell you something. (of course it will tell non-pros nothing , and they will just think it is broken)
with 4 amp protection, and precision same resistance, if any item was pulling more than its Share of the load (which will offset the set) the whole thing would cut out or flash.
Then you still can have problems with large capacity differences and STILL get cross charging (as can be prevented with diodes) but with 3 good working cells, that will live a good time , shouldnt be a problem. with 3 POS cells from Deal land , maby you should put in the diodes
if your going to be using the High Load (slightly lower capacity for size) 265s they are robust and should work fine for long times.
in simple, connect all the batts with same length of good copper wire
get the wires up top, and plop on 3x 4 amp protection (that is just 8 more solder points)
slip heat shrink around stuff
connect the trio of protection to the driver or whatever and Go.
like that it doesnt sound like a nightmare of stuff complicating your project.
