Desired systems approach to DC charging - discussion thread

[thomasow]

As suggested by:

Originally Posted by GoingWalkabout

. . . . Why don't we all draw up a wish list of what would be the best kind of interface and control technology for a simpler almost plug and play system for a choice or mix of input power sources. Draw up the specs and lets see if it can be built.

in a different thread, am starting a new one to open discussion. Several folks seem to see problems with what is currently offered to the Marine marketplace with regards to DC power - though problems likely a combination of real and perceived. Likewise, several folks see quality offerings in the marketplace by long established venders - again likely a combination of truth as well as marketing drive perception.

Perhaps this thread can shed some light on things. Myself I am rather new to the forum (at least in posts), but have been a boater for many years, and a 'full time cruiser' for going on 6 years now - where we are away from shore power for 8mo or so out of the year. We truly live on our batteries and charging sources. I also think what is sold to the marketplace and installed on a boat which sees perhaps 2-3 weeks of usage a year, and has ready access to shore power is at times a poor fit for a vessel which is much more self contained and used. And this is not restricted to electrical items

Aside from the classic reliable, two things I have noted with existing charging solutions which cause me concern are:

1. A almost industry wide pervasiveness to undercharge batteries - resulting in shorter lifespan – at least for Pb based technologies.
2. A fun and interesting 'king of the Hill' osculation between multiple charging sources (e.g., alternator and solar panels) where each has a different set point voltage, and perhaps idea on when to transition charging states.

I have my own ideas on these, and solution - and should disclose I have developed / am developing some open source components. But before getting to solution space, perhaps will be interesting to see what others have to say.

OK, let’s see if this goes anywhere - points out some opportunities - maybe even leads to something.

[n8kraft]

As a tech I want to have a variety of charging sources, wind and solar and want them to work together to put amperes in the bank, not work against each other. Some chargers don't work together so if solar is on then wind won't produce.

[tanglewood]

Personally what I think is needed is a distributed/networked control system for the charging sources. Perhaps a lofty goal, but I think that's what it takes to really make it all work properly.

For argument's sake, here's a rough outline of such a system:

- Current and voltage sense device at the battery bank, measuring current in/out of the bank, and providing a single, common voltage measurement for everyone else to use. Connect this gadget to the ship's N2K bus so it is providing this data for anyone and everyone. I believe all the standards exist today for such a device, in fact I think the devices might already exist in suitable form.

- Connect all charge controllers to the same N2K network, and have them use the provided battery reading to control their charge operation.

- By making the actual battery current available to the chargers, they can now correctly end their charge cycle without being tricked by load currents. They can see actual battery return current.

- Charge set points can be sent to all chargers so they are all the same. And by using the same voltage measurement source, they won't be playing king-of-the-hill any more, but rather all be pulling hard or backing off as needed.

Easy to say, but a little harder to do. And do you do it using open standards, or attempt to corner the market yourself?

[zboss]

Originally Posted by tanglewood

Personally what I think is needed is a distributed/networked control system for the charging sources. Perhaps a lofty goal, but I think that's what it takes to really make it all work properly.

For argument's sake, here's a rough outline of such a system:

- Current and voltage sense device at the battery bank, measuring current in/out of the bank, and providing a single, common voltage measurement for everyone else to use. Connect this gadget to the ship's N2K bus so it is providing this data for anyone and everyone. I believe all the standards exist today for such a device, in fact I think the devices might already exist in suitable form.

- Connect all charge controllers to the same N2K network, and have them use the provided battery reading to control their charge operation.

- By making the actual battery current available to the chargers, they can now correctly end their charge cycle without being tricked by load currents. They can see actual battery return current.

- Charge set points can be sent to all chargers so they are all the same. And by using the same voltage measurement source, they won't be playing king-of-the-hill any more, but rather all be pulling hard or backing off as needed.

Easy to say, but a little harder to do. And do you do it using open standards, or attempt to corner the market yourself?

Well, they already have that. Take a look at Mastervolts offerings:

MasterBus | Mastervolt Marine