I'm designing an active LIPO balancer for a hybrid power system that
recharges from a gas generator, so it needs to be a lot different from a
passive/resistor type balancer you'd have on a normal battery charger. For
starters, my battery pack (a 12Sx3.3volt battery built from A123 26650
cells - 39.6 total stack voltage) will never (not from the generator
anyway) be allowed to charge above more than about 70 percent SOC, and
never allowed to drain below about 40 percent SOC before the charging
generator comes back on.
Obviously I need the ability to actively and precisely balance the
voltages during heavy discharge and charging both, and I'll never (or rarely) get
the opportunity to do a top or bottom balance like normal chargers do.
It's worth it to me to spend good money on the best and most efficient
design I can do on this balancer so as to lower the fuel consumption of
the generator engine.
My current design I'm drawing right now, is based on two chips from
Linear Technology. The first is the LTC 3300-1 balancer controller.
I'll need two of these to do a 12S stack of batteries. The second chip
is the LTC 6804-1 or-2 which is a battery voltage monitor that
integrates with the LTC 3300-1.chip. This setup allows me to use tiny,
low cost, off-the-shelf flyback transformers I can buy instead of having
to make a custom transformer(s).
I will have connect my own micro-controller to this setup and provide
my own software to control it, which will be written especially for the
charging needs (staying between 40-70 percent SOC) of a series
gas/hybrid charging system. Charging above about 70 percent is too
wasteful with gas.
Now that you know the story, my question is this:
Do other companies besides Linear Technology make controller chips similar to what I'm already planning to use, or do these two represent the current state of the art in actve LIPO balancer design? Is there some other better idea than using flyback transformers to build an active LIPO balancer? I'm interested in taking a sort of survey on what's available so I can compare features. If anyone makes a single chip that does the functions of both the LTC 3300-1 and the LTC 6804-1, I'd really like to hear about it.
Thanks an advance for any help.
Meadows.
recharges from a gas generator, so it needs to be a lot different from a
passive/resistor type balancer you'd have on a normal battery charger. For
starters, my battery pack (a 12Sx3.3volt battery built from A123 26650
cells - 39.6 total stack voltage) will never (not from the generator
anyway) be allowed to charge above more than about 70 percent SOC, and
never allowed to drain below about 40 percent SOC before the charging
generator comes back on.
Obviously I need the ability to actively and precisely balance the
voltages during heavy discharge and charging both, and I'll never (or rarely) get
the opportunity to do a top or bottom balance like normal chargers do.
It's worth it to me to spend good money on the best and most efficient
design I can do on this balancer so as to lower the fuel consumption of
the generator engine.
My current design I'm drawing right now, is based on two chips from
Linear Technology. The first is the LTC 3300-1 balancer controller.
I'll need two of these to do a 12S stack of batteries. The second chip
is the LTC 6804-1 or-2 which is a battery voltage monitor that
integrates with the LTC 3300-1.chip. This setup allows me to use tiny,
low cost, off-the-shelf flyback transformers I can buy instead of having
to make a custom transformer(s).
I will have connect my own micro-controller to this setup and provide
my own software to control it, which will be written especially for the
charging needs (staying between 40-70 percent SOC) of a series
gas/hybrid charging system. Charging above about 70 percent is too
wasteful with gas.
Now that you know the story, my question is this:
Do other companies besides Linear Technology make controller chips similar to what I'm already planning to use, or do these two represent the current state of the art in actve LIPO balancer design? Is there some other better idea than using flyback transformers to build an active LIPO balancer? I'm interested in taking a sort of survey on what's available so I can compare features. If anyone makes a single chip that does the functions of both the LTC 3300-1 and the LTC 6804-1, I'd really like to hear about it.
Thanks an advance for any help.
Meadows.
