EV Works BMS with PFC-20

[Rob Trahms]

Hi all -

I am still researching LiFePO4 BMSs that will work with my (soon-to-be) 144V lithium pack and existing PFC-20 and Z1K-HV.

I have heard about EV Works' BMS-MCU-TS90-EV2 control unit.  Seems reasonably inexpensive, and achieves balancing with its associated cell modules:

http://www.evworks.com.au/index.php?product=BMS-MCU-TS90-EV2

Who has worked with this unit, and what are your experiences?

Two questions:
1) the unit has a manual reset, which would trigger (I think) if current goes beyond what the balancers can shunt after the cells are fully charged.  If my PFC-20 is properly tuned to taper at the proper voltage, this reset should rarely be needed, right?  I don't want to push that button every time I have to charge the pack.

2) Beyond the (barely) audible alarm, this system would not help me with the over-discharge condition, but my Zilla already has that protection as the low voltage limit.  Can I rely on my Z1K low voltage limit to protect from this over-discharge condition?

Thanks,
Rob

[Willie McKemie-3]

On Wed, Nov 04, 2009 at 06:13:08AM -0800, Rob Trahms wrote:

> Two questions:
> 1) the unit has a manual reset, which would trigger (I think) if current
> goes beyond what the balancers can shunt after the cells are fully charged.
> If my PFC-20 is properly tuned to taper at the proper voltage, this reset
> should rarely be needed, right?  I don't want to push that button every time
> I have to charge the pack.

That's correct; if your charger will cut back to 500 ma or less at the
proper pack voltage and your pack is balanced, you will achieve steady
state with the charger running forever and the balancers eventually
dissipating all the energy.  That's the desired scenario.  The BMS
shutting down the charger is a fail-safe mechanism and indicates a
problem that needs to be corrected.
>
> 2) Beyond the (barely) audible alarm, this system would not help me with the
> over-discharge condition, but my Zilla already has that protection as the
> low voltage limit.  Can I rely on my Z1K low voltage limit to protect from
> this over-discharge condition?

The Zilla is seeing pack voltage and the BMS alarm is in response to
low voltage on a single cell.  The BMS will tell you if there is a
problem with a single cell and your Zilla will likely not.  You will
likely damage your pack if you discharge it until the Zilla notices
low voltage.  The purpose of the BMS low voltage alarm is to notify you
of a single cell problem; you should not encounter the alarm condition
if your pack is in good condition and you do not over discharge it.

For avoiding over-discharge of the entire pack, I think it is
desirable to rely on a meter such as the TBS.  Using my TBS, I have
never encountered an un-expected low pack.  That's only in the less
than 7K miles of my experience, though.  I had brief experience with
lead and gauging energy remaining was an art rather than anything
else.  With lithium, you can measure how much energy you put in
(charge) and how much you take out.  Knowing or guessing the capacity
of your pack, you then know at ANY time how much energy you have
available in the pack.  I have found that the TBS gives me a very
accurate and reliable measure of remaining energy.

Incidentally, I've been exploring chargers that are suitable for
lithium.  More specifically, suitable for lithium with the EVPower BMS.
The Zivan is ok if you learn to adjust it.  But the Zivan is a single
input voltage device.  I've explored Elcon and Chinoz which are very
attractively priced, but they seem to be either not adjustable or are
difficult to adjust.  I've asked about how a Russco might be used, but
haven't gotten a response from them.  I have no experience with
Manzanita, they look very promising though a bit costly.  I do worry
about bumping a very precisely adjusted knob; is that a valid worry?


--
Willie, ONWARD!  Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime  690 days  6 hours 26 minutes

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[Rob Trahms]

Good information.  I was looking at the TBS meters - interesting!
I assume I would have to use one with the 10:1 prescaler for a voltage
of (now) 170V pack, right?

Rob

Willie McKemie-3 wrote:

On Wed, Nov 04, 2009 at 06:13:08AM -0800, Rob Trahms wrote:

> Two questions:
> 1) the unit has a manual reset, which would trigger (I think) if current
> goes beyond what the balancers can shunt after the cells are fully charged.
> If my PFC-20 is properly tuned to taper at the proper voltage, this reset
> should rarely be needed, right?  I don't want to push that button every time
> I have to charge the pack.

That's correct; if your charger will cut back to 500 ma or less at the
proper pack voltage and your pack is balanced, you will achieve steady
state with the charger running forever and the balancers eventually
dissipating all the energy.  That's the desired scenario.  The BMS
shutting down the charger is a fail-safe mechanism and indicates a
problem that needs to be corrected.
>
> 2) Beyond the (barely) audible alarm, this system would not help me with the
> over-discharge condition, but my Zilla already has that protection as the
> low voltage limit.  Can I rely on my Z1K low voltage limit to protect from
> this over-discharge condition?

The Zilla is seeing pack voltage and the BMS alarm is in response to
low voltage on a single cell.  The BMS will tell you if there is a
problem with a single cell and your Zilla will likely not.  You will
likely damage your pack if you discharge it until the Zilla notices
low voltage.  The purpose of the BMS low voltage alarm is to notify you
of a single cell problem; you should not encounter the alarm condition
if your pack is in good condition and you do not over discharge it.

For avoiding over-discharge of the entire pack, I think it is
desirable to rely on a meter such as the TBS.  Using my TBS, I have
never encountered an un-expected low pack.  That's only in the less
than 7K miles of my experience, though.  I had brief experience with
lead and gauging energy remaining was an art rather than anything
else.  With lithium, you can measure how much energy you put in
(charge) and how much you take out.  Knowing or guessing the capacity
of your pack, you then know at ANY time how much energy you have
available in the pack.  I have found that the TBS gives me a very
accurate and reliable measure of remaining energy.

Incidentally, I've been exploring chargers that are suitable for
lithium.  More specifically, suitable for lithium with the EVPower BMS.
The Zivan is ok if you learn to adjust it.  But the Zivan is a single
input voltage device.  I've explored Elcon and Chinoz which are very
attractively priced, but they seem to be either not adjustable or are
difficult to adjust.  I've asked about how a Russco might be used, but
haven't gotten a response from them.  I have no experience with
Manzanita, they look very promising though a bit costly.  I do worry
about bumping a very precisely adjusted knob; is that a valid worry?


--
Willie, ONWARD!  Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime  690 days  6 hours 26 minutes

_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev

[Willie McKemie-3]

On Wed, Nov 04, 2009 at 08:40:40PM -0800, Rob Trahms wrote:
>
>
> Good information.  I was looking at the TBS meters - interesting!
> I assume I would have to use one with the 10:1 prescaler for a voltage
> of (now) 170V pack, right?

I THINK so.  My 45 cell pack uses a 5:1.  Xantrex is apparently
re-branding the TBS as a "LinkPro" but not offering the prescalers:
http://is.gd/4NLbe
However, Belktronix is offering a very attractively priced 10:1
prescaler for it:
http://belktronix.com/LinkProAdapter.html

--
Willie, ONWARD!  Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime  691 days 19 min minutes

_______________________________________________
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Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev

[tomw]

That's correct.  The 5:1 prescaler works for packs up to 132V.  I contacted Xantrex to purchase the gauge and prescaler, but they said they only sell the gauge and could not or would not order the prescaler.  I verified with TBS a few months ago that there were no other U.S. dealers at that time, although they said they were looking into some.  I purchased it from evworks in Australia.  I don't know why no U.S. ev suppliers carry it, as combined with some inexpensive shunt regulators like Voltblochers it gives you SOC, battery V, I, and HVC/LVC signals with shunt regulation for much less than other "bms" systems.

TomW

Rob Trahms wrote:

Good information.  I was looking at the TBS meters - interesting!
I assume I would have to use one with the 10:1 prescaler for a voltage
of (now) 170V pack, right?

Rob

Willie McKemie-3 wrote:

On Wed, Nov 04, 2009 at 06:13:08AM -0800, Rob Trahms wrote:

> Two questions:
> 1) the unit has a manual reset, which would trigger (I think) if current
> goes beyond what the balancers can shunt after the cells are fully charged.
> If my PFC-20 is properly tuned to taper at the proper voltage, this reset
> should rarely be needed, right?  I don't want to push that button every time
> I have to charge the pack.

That's correct; if your charger will cut back to 500 ma or less at the
proper pack voltage and your pack is balanced, you will achieve steady
state with the charger running forever and the balancers eventually
dissipating all the energy.  That's the desired scenario.  The BMS
shutting down the charger is a fail-safe mechanism and indicates a
problem that needs to be corrected.
>
> 2) Beyond the (barely) audible alarm, this system would not help me with the
> over-discharge condition, but my Zilla already has that protection as the
> low voltage limit.  Can I rely on my Z1K low voltage limit to protect from
> this over-discharge condition?

The Zilla is seeing pack voltage and the BMS alarm is in response to
low voltage on a single cell.  The BMS will tell you if there is a
problem with a single cell and your Zilla will likely not.  You will
likely damage your pack if you discharge it until the Zilla notices
low voltage.  The purpose of the BMS low voltage alarm is to notify you
of a single cell problem; you should not encounter the alarm condition
if your pack is in good condition and you do not over discharge it.

For avoiding over-discharge of the entire pack, I think it is
desirable to rely on a meter such as the TBS.  Using my TBS, I have
never encountered an un-expected low pack.  That's only in the less
than 7K miles of my experience, though.  I had brief experience with
lead and gauging energy remaining was an art rather than anything
else.  With lithium, you can measure how much energy you put in
(charge) and how much you take out.  Knowing or guessing the capacity
of your pack, you then know at ANY time how much energy you have
available in the pack.  I have found that the TBS gives me a very
accurate and reliable measure of remaining energy.

Incidentally, I've been exploring chargers that are suitable for
lithium.  More specifically, suitable for lithium with the EVPower BMS.
The Zivan is ok if you learn to adjust it.  But the Zivan is a single
input voltage device.  I've explored Elcon and Chinoz which are very
attractively priced, but they seem to be either not adjustable or are
difficult to adjust.  I've asked about how a Russco might be used, but
haven't gotten a response from them.  I have no experience with
Manzanita, they look very promising though a bit costly.  I do worry
about bumping a very precisely adjusted knob; is that a valid worry?


--
Willie, ONWARD!  Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime  690 days  6 hours 26 minutes

_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev

[Willie McKemie-3]

On Sat, Nov 07, 2009 at 06:07:21AM -0800, tomw wrote:
>
> That's correct.  The 5:1 prescaler works for packs up to 132V.  I contacted

My 5:1 prescaler works fine on a 45 cell pack that goes up to around
165v

> Xantrex to purchase the gauge and prescaler, but they said they only sell
> the gauge and could not or would not order the prescaler.  I verified with
> TBS a few months ago that there were no other U.S. dealers at that time,
> although they said they were looking into some.  I purchased it from evworks
> in Australia.  I don't know why no U.S. ev suppliers carry it, as combined

http://belktronix.com/LinkProAdapter.html


--
Willie, ONWARD!  Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime  693 days 14 hours 23 minutes

_______________________________________________
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Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev

[Nancy Loo]

We're ElCon PFC charger manufacturer.

It is not the only way to have BMS for Lithium battery.
The Battery Protection Board is another option. It is much cheaper that BMS.  We can set the fixed maximum voltage before delivery.  When the charger is powered on, it begins charging if there is external control single from battery protection board. When the charger is working, it employs constant current in the beginning, and then constant voltage. In the constant voltage, when the current reduces to a specific value,  the charging period ends. If control single cuts off at any time, the charging will end.  There are two control lines. It needs to connect 5V~12V. The current 10mA is required.

Any query please inform us.

[e-mail]

www.hztiecheng.com

Willie McKemie-3 wrote:

On Wed, Nov 04, 2009 at 06:13:08AM -0800, Rob Trahms wrote:

> Two questions:
> 1) the unit has a manual reset, which would trigger (I think) if current
> goes beyond what the balancers can shunt after the cells are fully charged.
> If my PFC-20 is properly tuned to taper at the proper voltage, this reset
> should rarely be needed, right?  I don't want to push that button every time
> I have to charge the pack.

That's correct; if your charger will cut back to 500 ma or less at the
proper pack voltage and your pack is balanced, you will achieve steady
state with the charger running forever and the balancers eventually
dissipating all the energy.  That's the desired scenario.  The BMS
shutting down the charger is a fail-safe mechanism and indicates a
problem that needs to be corrected.
>
> 2) Beyond the (barely) audible alarm, this system would not help me with the
> over-discharge condition, but my Zilla already has that protection as the
> low voltage limit.  Can I rely on my Z1K low voltage limit to protect from
> this over-discharge condition?

The Zilla is seeing pack voltage and the BMS alarm is in response to
low voltage on a single cell.  The BMS will tell you if there is a
problem with a single cell and your Zilla will likely not.  You will
likely damage your pack if you discharge it until the Zilla notices
low voltage.  The purpose of the BMS low voltage alarm is to notify you
of a single cell problem; you should not encounter the alarm condition
if your pack is in good condition and you do not over discharge it.

For avoiding over-discharge of the entire pack, I think it is
desirable to rely on a meter such as the TBS.  Using my TBS, I have
never encountered an un-expected low pack.  That's only in the less
than 7K miles of my experience, though.  I had brief experience with
lead and gauging energy remaining was an art rather than anything
else.  With lithium, you can measure how much energy you put in
(charge) and how much you take out.  Knowing or guessing the capacity
of your pack, you then know at ANY time how much energy you have
available in the pack.  I have found that the TBS gives me a very
accurate and reliable measure of remaining energy.

Incidentally, I've been exploring chargers that are suitable for
lithium.  More specifically, suitable for lithium with the EVPower BMS.
The Zivan is ok if you learn to adjust it.  But the Zivan is a single
input voltage device.  I've explored Elcon and Chinoz which are very
attractively priced, but they seem to be either not adjustable or are
difficult to adjust.  I've asked about how a Russco might be used, but
haven't gotten a response from them.  I have no experience with
Manzanita, they look very promising though a bit costly.  I do worry
about bumping a very precisely adjusted knob; is that a valid worry?


--
Willie, ONWARD!  Through the fog!
http://counter.li.org Linux registered user #228836 since 1995
Debian3.1/GNU/Linux system uptime  690 days  6 hours 26 minutes

_______________________________________________
General EVDL support: http://evdl.org/help/
Usage guidelines: http://evdl.org/help/index.html#conv
Archives: http://evdl.org/archive/
Subscription options: http://lists.sjsu.edu/mailman/listinfo/ev