# Jumpstarting DIY controller



## piotrsko (Dec 9, 2007)

the only down side that I can see is that the starting subpack on the beginning of the conga line tends to become depleted faster than all the other packs. Perhaps physically rotating the lower numbered packs every couple of charge cycles?


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## CPLTECH (Sep 14, 2007)

The issue I would be concerned about is that the individual batteries are discharged at different rates. Now, how do you get each battery charged back up where it is supposed to be each night? That is where a PWM controller excels since it draws power from the whole pack. Is this the ideal place for a BMS?

I am slowly getting my pack into shape after a 2 day power outage & used 4 of the 20 to run the freezer.


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## ga2500ev (Apr 20, 2008)

I will address both issues.

The subpacks are not numbered. They are individually measured for voltage and the lowest voltage pack in a group is swapped out while the highest voltage subpack in the group is swapped in.

As for uneven discharging, the packs are checked/swapped at 100 Hz. So a subpack that currently loaded will quickly by rotated out. The bottom line is that the energy consumption of the subpacks are pretty even, though not exact like a PWM controller.

Finally for charging with lead acid, nothing is simpler than Lee Hart's zener regulators across each battery. When a battery comes fully charged, the regulator will bypass power to light the lamps, thus saving the battery from overcharging. A simple and effective BMS for lead acid.

The subpack management issue seems to be well thought out. I'm trying to figure out the construction complexity and parts costs.

ga2500ev


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## order99 (Sep 8, 2008)

That's...interesting. Sadly, my current knowledge of Electronics consists of "don't stick the fork in the toaster"  but sounds pretty nice on paper. Is this prototype going to be released for Sale or will it be Open Source ? Also, can it be adapted for the different types of Motor out there, or is the design best on one type (series, sep-ex etc)?


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## ga2500ev (Apr 20, 2008)

order99 said:


> That's...interesting. Sadly, my current knowledge of Electronics consists of "don't stick the fork in the toaster"  but sounds pretty nice on paper. Is this prototype going to be released for Sale or will it be Open Source ?


Anything I produce will be Open Source.


> Also, can it be adapted for the different types of Motor out there, or is the design best on one type (series, sep-ex etc)?


I would guess series.

ga2500ev


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## Oiladdict (Nov 9, 2008)

It looks like that site hasn't been updated since 2003. I wonder if his system is still in use. 
I don't have an electronics background either, but this looks like a great concept. 
I will be reading this thread and helping out where I can.


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