
It started as a stain on the page in.....
hyjacked topic
Go for it...
Here is my circuit again just to start the topic here.
NOTE. Transistor used in final version was KSH127
acmotor wrote: All important.
0 Safe... excludes bipolar /fet junction directly across cell ! and resistor whose power rating is exceeded by full on pwm from micro.
I think is both simplest and best. (hard to stuff up)acmotor wrote: 8 can be just visual at the cell ?
I saw a4x4kiwi contactors which split his pack into 12 x 48V packs and a 24V pack for charging. It made sense for me to join them all in parallel to 1 48V pack for use with a big charger.acmotor wrote: 9 interesting... are you thinking of this while pack powered down only ? Just use a mechanical SPDT switch ? can be AC rated as it will not be operated with live DC.
Change-over 600VDC relays may be expensive.
48V Bus + ---O O--- + 48v block - ---O O--- - 48V Bus / \ prev 48V block ---O O-----(bypass)-------O O--- - next 48 V blockWhen the contactor was energised (show), the blocks join together to make the 600V chain, when unenergised, they join onto a common 48V bus for charging.
I think a4x4kiwi is testing that for us at the moment!Johny wrote:Do eCrazymans's chargers work OK with the zener-resistor system?
woody wrote: Same site has links to about 15 differnet BMSes available, in progress.
Johny wrote: Are there any specs on the chargers - like current required for float switch? I'll assume not so how hard would it be to gently test a couple of them to determine what the current at switch point is? I suspect this might have to involve a longish time (a few seconds at each current) unless they don't bother to "smooth" the current reading.
My concern is that the zener-resistor system is near the threshold and some switch but some don't - result, unbalanced 600V pack.