Sorry for the delays, but this time of year, my time is not my own.
Nick, if you want all functions, physically on the bike, I think the full BMS is what you will need. This is not quite available yet, but should not be too far behind the rest of the balancers, etc. The current issue is how we do the LVC function, opto-based, or with the "ladder" type implementation. It really depends on whether we include a option for active cutoff or not. If we stick with the simple "pull-down-the-throttle-signal" implementation, to remove the load, the opto-based circuit we've always used makes the most sense. We are looking at active cutoff options, but you can't simply cycle the full pack power on and off, as an LVC circuit trips, and then resets, as the controller won't be happy. Instead, we are looking at combo cutoff function that uses the pulldown method on the throttle, to handle cases when the LVC is tripping due to high loads, and then uses active cutoff only for the cases where a controller was left on, for instance, and the cells are slowly being drained down. Anyway, we are close to sorting this out, and as soon as we do I'll add it to the PCB layouts for the full BMS, and get them submitted.
I'm just about done with the instructions and the BOMs for all the different CellLog-based balancers. In addition to the 12-channel version there will be variants for 8, 16 and 18 channels. I hope to get this finished up before the end of today, or at least before the end of the weekend, and then make them available.
As I've mentioned, I'm also looking at adding an HVC capability back into the LVC/parallel adapter boards, to handle the case, primarily for LiPo setups, where the cells are still fairly well balanced, so just a bulk charge needs to be done. I'm really only comfortable doing this, however, as long as the HVC function is present, to act as a failsafe against damaged cells overcharging and running the risk of thermal runaway. For my first cut at this, I thought I'd kill two birds, and implement Randomly's active cutoff circuit, and make use of his matching LVC circuits. I did this, and added HVC to this as well, but there were a couple of hiccups. The problem is that Randomly's "ladder" based circuit that replaces the optos, requires that the first and last channels be different than the rest. I was able to do the 6-channel boards in a way that allowed any of these boards to be used as the first board in the string, the last board in the string, or one of the ones in between. To do this, jumpers are used, a couple parts added and a couple are omitted. If you are making one big pack, this is not really a problem, but it became a showstopper for my own setups. On my main bike, I have two identical 12s3p Turnigy packs, that are connected in series on the bike. I have a third 12s3p pack that will eventually become part of an identical 24s3p setup on my wife's bike. For now, I've been rotating the three packs on my bike. In any case, it isn't really practical for me to designate one 12s3p pack as the "first" one, and the second as the "last" one. I want to keep these identical.
The other "hiccup" I have is like I've mentioned above, I just don't think it is wise to cycle power on the controller when the LVC trips, so I want to wait until we have a suitable "dual-mode" active cutoff function, before making use of this on my own setups. In any case, I was back to square 1, in terms of still wanting to add an HVC capability for bulk charging without the CellLogs/balancers connected. I still have some of my previous LVC.HVC combo boards, so I could use those, but frankly I just don't feel like ripping my packs apart again, to swap out the LVC-only boards for the LVC/HVC variants. Instead, my laziness has generated an idea to do a very simple, HVC-only board. What I will do is uses a couple of these and attach them to one of the 14-pin VAL-U-LOK plugs that is the same as what I use with the 12-channel balancer. I'll shrink-wrap this assembly all together and simply plug it into the same connector coming from the pack I use when with the balancer. The other end of this will be the 2-wire HVC pigtail that will attach to the MeanWell charge controller (or to a standalone Charge Controller...). Here's what these boards look like:
These will work equally well with any of the existing LVC boards, and also with Geoff's new SMD-version of the same LVC circuit. For new setups, I'll also do an updated version of the combined LVC/HVC boards, both 6-channel and 8-channel variants, and I'll probably do an 8-channel version of the HVC-only board as well, just for completeness. Functionally, it makes no difference if the HVC is combined, or if it is separate. When balancing is required, the CellLog unit provides the HVC function.
Anyway, back to work...
-- Gary
