It's time for me to upgrade my EV transportation. I've been running VRSLA for
the last five years or so. In my current EV, a 2003 Gizmo, I'm running a
comfortable 25 mile range in ordinary temperatures. Unfortunately, it's been
rather cold here in the frozen south and I'm also wanting to have an increased
range overall.
Clearly the answer to this is LiFePO4, at least in my alleged mind. David
Nelson, also a Gizmo owner, has a rack of TS cells and his experience is good.
I'm not so sure about TS cells though and would like to ensure my investment
remains as healthy as possible over time. I envision five thousand miles or more
a year, almost exclusively flat ground.
My envisioning also includes the ability to record each cell performance during
operation and charging, similar to the information that the PakTrakr provides
now in my pack. I'm thinking I should also have some low voltage and high
voltage protection during discharge and recharge, respectively. Bluetooth output
to an alleged smart phone, android-based would be a bonus, although ordinary
RS232c via netbook is acceptable.
My current pack is eight Deka 8G31 batteries, wedged pretty tightly in the
battery box, tightly enough that the top flange on each battery prevents the
pack from sitting flat in the box. I've solved that by putting floor-foam-tiles
under alternating batteries, those things that you can put down for play areas
or just something comfortable on which to stand. The factory battery box is the
only location in which to place batteries and I do have a bit of leeway in terms
of height, but that's about it. I'd like to have as close to 200ah as possible.
The pack in place now provides nearly that figure, ignoring the Peukert effect,
of course and the fifty-percent discharge limit.
As David Nelson has discovered, our controller and DC/DC converter can both
handle 60v, so I'm aiming for that figure, more or less. I'll have to confirm
the numbers to be more certain, but it means that it's likely that 20 TS type
cells should work. David worked within the physical constraints of his battery
box by using 2x100ah cells in a 2p20s configuration. I'm not sure of the
terminology, but it's pairs of cells in parallel, strung in a series
arrangement.
My pack is currently four batteries in serial, duplicated. I'm thinking that
David's is two batteries in parallel, twenty times in serial. Is there a reason
to not string 20 cells in serial, then parallel another pack of 20 with it?
As part of my objective, I'd like to have some form of equalizer or balancer or
dare I use that term BMS? I'm running PowerCheq equalizers on my pack now and
have had it on the long-gone Xebra and attribute the long life of the packs to
those devices, along with my strict limitation to fifty percent DoD. I'd like to
keep that capability in the next chemistry.
This is more-or-less a request for quote, in a less-formal manner. I'd like to
hear from vendors especially, to have them make me an offer I can't refuse, as
long as the general consensus agrees with the conclusions provided by the
vendors. I would also want a charger "tuned" to the pack, even though I
understand that mine is capable. I don't want to have the vehicle out of service
by the additional time required to ship the Zivan out for reprogramming.
Comments, suggestions and proposals are welcome.
Onward into the fog...
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the last five years or so. In my current EV, a 2003 Gizmo, I'm running a
comfortable 25 mile range in ordinary temperatures. Unfortunately, it's been
rather cold here in the frozen south and I'm also wanting to have an increased
range overall.
Clearly the answer to this is LiFePO4, at least in my alleged mind. David
Nelson, also a Gizmo owner, has a rack of TS cells and his experience is good.
I'm not so sure about TS cells though and would like to ensure my investment
remains as healthy as possible over time. I envision five thousand miles or more
a year, almost exclusively flat ground.
My envisioning also includes the ability to record each cell performance during
operation and charging, similar to the information that the PakTrakr provides
now in my pack. I'm thinking I should also have some low voltage and high
voltage protection during discharge and recharge, respectively. Bluetooth output
to an alleged smart phone, android-based would be a bonus, although ordinary
RS232c via netbook is acceptable.
My current pack is eight Deka 8G31 batteries, wedged pretty tightly in the
battery box, tightly enough that the top flange on each battery prevents the
pack from sitting flat in the box. I've solved that by putting floor-foam-tiles
under alternating batteries, those things that you can put down for play areas
or just something comfortable on which to stand. The factory battery box is the
only location in which to place batteries and I do have a bit of leeway in terms
of height, but that's about it. I'd like to have as close to 200ah as possible.
The pack in place now provides nearly that figure, ignoring the Peukert effect,
of course and the fifty-percent discharge limit.
As David Nelson has discovered, our controller and DC/DC converter can both
handle 60v, so I'm aiming for that figure, more or less. I'll have to confirm
the numbers to be more certain, but it means that it's likely that 20 TS type
cells should work. David worked within the physical constraints of his battery
box by using 2x100ah cells in a 2p20s configuration. I'm not sure of the
terminology, but it's pairs of cells in parallel, strung in a series
arrangement.
My pack is currently four batteries in serial, duplicated. I'm thinking that
David's is two batteries in parallel, twenty times in serial. Is there a reason
to not string 20 cells in serial, then parallel another pack of 20 with it?
As part of my objective, I'd like to have some form of equalizer or balancer or
dare I use that term BMS? I'm running PowerCheq equalizers on my pack now and
have had it on the long-gone Xebra and attribute the long life of the packs to
those devices, along with my strict limitation to fifty percent DoD. I'd like to
keep that capability in the next chemistry.
This is more-or-less a request for quote, in a less-formal manner. I'd like to
hear from vendors especially, to have them make me an offer I can't refuse, as
long as the general consensus agrees with the conclusions provided by the
vendors. I would also want a charger "tuned" to the pack, even though I
understand that mine is capable. I don't want to have the vehicle out of service
by the additional time required to ship the Zivan out for reprogramming.
Comments, suggestions and proposals are welcome.
Onward into the fog...
-------------- next part --------------
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| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
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| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
