<div dir="ltr"><br><div>Yes - those protection circuits could likely work for DPRG use cases.</div><div><br></div><div>You can find ready made and protected packs from Tenergy. They're nice, but they're at a premium.</div><div><br></div><div>I understand that most hobby packs don't use them because, e.g. you need 50+ amps peak for cases like drones and planes. I understood those devices run so close to the max peak capacity of the pack, that there's no point in having a protection circuit...</div><div><br></div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Feb 6, 2019 at 8:43 AM <<a href="mailto:deltagraph@aol.com">deltagraph@aol.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><font color="black" size="2" face="Arial, Helvetica, sans-serif">
<div><font size="2">Looking at gizmos to disconnect pack from load<br>
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<div><font size="2">Something like this (only prob did not see price and 1000 units here... )</font><br>
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<div><a href="http://www.all-battery.com/PCBfor11.1VLIPO_Li-Ion_Li-MnNiBatteryPack-32071.aspx" target="_blank"><font size="2">http://www.all-battery.com/PCBfor11.1VLIPO_Li-Ion_Li-MnNiBatteryPack-32071.aspx</font></a></div>
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<div><font size="2">Here $10 -- would assume not getting put in most hobby li-po batteries.</font><br>
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<div><a href="http://www.all-battery.com/PCB11-1V32048.aspx?utm_source=GoogleShopping&utm_medium=GDF&gdffi=fb520bc42d4e46cbab702234d35f7d38&gdfms=035D4896756F4B048ACF314139800B9C&gclid=CjwKCAiAqOriBRAfEiwAEb9oXb6wTFeIxqMP7oYxr6O--SDNpFQJl-caWL56UZPRG4jMzg4eviUjCBoCW0YQAvD_BwE" target="_blank"><font size="2">http://www.all-battery.com/PCB11-1V32048.aspx?utm_source=GoogleShopping&utm_medium=GDF&gdffi=fb520bc42d4e46cbab702234d35f7d38&gdfms=035D4896756F4B048ACF314139800B9C&gclid=CjwKCAiAqOriBRAfEiwAEb9oXb6wTFeIxqMP7oYxr6O--SDNpFQJl-caWL56UZPRG4jMzg4eviUjCBoCW0YQAvD_BwE</font></a></div>
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<div><font size="2">Of course more interest would be simply monitor and disconnect due to discarge, not overvoltage protect during charge since that is managed by charger... <br>
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<div><font size="2">Ron</font><br>
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<div style="font-family:arial,helvetica;font-size:10pt;color:black">-----Original Message-----<br>
From: Carl Ott <<a href="mailto:carl.ott.jr@gmail.com" target="_blank">carl.ott.jr@gmail.com</a>><br>
To: Ron Grant <<a href="mailto:deltagraph@aol.com" target="_blank">deltagraph@aol.com</a>><br>
Cc: DPRG D-List <<a href="mailto:dprglist@dprg.org" target="_blank">dprglist@dprg.org</a>><br>
Sent: Wed, Feb 6, 2019 7:26 am<br>
Subject: Re: [Dprglist] For your next robot - handy dc-dc converters - 3S LiPo to RPi<br>
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<div dir="ltr">These packs show ratings of 8 ~ 20 volts, or 8 ~ 50 volts so, even when starting at a full 4.2v charge, 2S probably wouldn't work, at least not for long...
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<div>In terms of voltage monitors, I've been using one of these for a while - they're pretty nice</div>
<div><a rel="noopener noreferrer" shape="rect" href="https://us.banggood.com/Wholesale-Warehouse-0_28-Inch-2_5V-30V-Mini-Digital-Voltmeter-wp-Usa-974258.html?akmClientCountry=America&rmmds=myorder" target="_blank">https://us.banggood.com/Wholesale-Warehouse-0_28-Inch-2_5V-30V-Mini-Digital-Voltmeter-wp-Usa-974258.html?akmClientCountry=America&rmmds=myorder</a><br clear="none"></div>
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<div>The 2016 club robot came with one of these</div>
<div><a rel="noopener noreferrer" shape="rect" href="https://www.amazon.com/Battery-Monitor-Voltage-Checker-Indicator/dp/B013U1CP08/ref=asc_df_B013U1CP08/?tag=hyprod-20&linkCode=df0&hvadid=167139094796&hvpos=1o1&hvnetw=g&hvrand=8040392104640112483&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9026796&hvtargid=pla-304998738630&psc=1" target="_blank">https://www.amazon.com/Battery-Monitor-Voltage-Checker-Indicator/dp/B013U1CP08/ref=asc_df_B013U1CP08/?tag=hyprod-20&linkCode=df0&hvadid=167139094796&hvpos=1o1&hvnetw=g&hvrand=8040392104640112483&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9026796&hvtargid=pla-304998738630&psc=1</a><br clear="none"></div>
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<div>looks like it can work nicely if your battery has a balancing port. it monitors the voltage on each cell in the pack. you can set the alarm threshold voltage to your preference. But it does beep every time you power it up, and seems to cycle the display through each of the cell voltages - so it looks like a good alarm but is not as simple as a voltage gauge on the entire pack.</div>
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<div>- Carl</div>
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<div class="gmail-m_3815267236815112858yiv8522368316gmail_attr" dir="ltr">On Wed, Feb 6, 2019 at 7:02 AM <<a rel="noopener noreferrer" shape="rect" href="mailto:deltagraph@aol.com" target="_blank">deltagraph@aol.com</a>> wrote:<br clear="none"></div>
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<div><font size="2">Hey Carl/All,</font></div>
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<div><font size="2">Looks nice, but would be nice to have auto disconnect of converter on low voltage -- of course that can be addressed separately, up line at the input of the dc-dc converter.<br clear="none">
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<div><font size="2">Voltage monitoring by MCU (with suitable voltage divider) or display with one of those $1 LED display modules is handy, just thinking more about accidental leaving converter/load connected to battery.</font></div>
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<div><font size="2">Maybe someone can shed some light on how many li-po packs have auto low-voltage shutoff these days.</font></div>
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<div><font size="2">At first I was thinking about this converter being used with a 3 cell pack, wonder if it would work with a 2 cell pack?</font></div>
<div><font size="2">If so, at least the pi would die before the battery. You still would need to disconnect battery, but at least brain death would precede battery death.<br clear="none">
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<div><font size="2">Ron<br clear="none">
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<div style="font-family:arial,helvetica;font-size:10pt;color:black">-----Original Message-----<br clear="none">
From: Carl Ott via DPRGlist <<a rel="noopener noreferrer" shape="rect" href="mailto:dprglist@lists.dprg.org" target="_blank">dprglist@lists.dprg.org</a>><br clear="none">
To: DPRG D-List <<a rel="noopener noreferrer" shape="rect" href="mailto:dprglist@dprg.org" target="_blank">dprglist@dprg.org</a>><br clear="none">
Sent: Tue, Feb 5, 2019 8:07 pm<br clear="none">
Subject: [Dprglist] For your next robot - handy dc-dc converters - 3S LiPo to RPi<br clear="none">
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<div id="gmail-m_3815267236815112858yiv8522368316gmail-m_-5039002557448077184yiv3915880622">
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<div dir="ltr">FWIW </div>
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<div>Found these - should come in handy powering Raspberry Pi from a 3S LiPo pack. Haven't powered them up yet - but the specs look good</div>
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<div dir="ltr">this one is a little smaller, with just Micro-USB out<br clear="none">
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<div><a rel="noopener noreferrer" shape="rect" href="https://smile.amazon.com/gp/product/B00O6RJLQC/ref=ppx_yo_dt_b_asin_title_o03__o00_s00?ie=UTF8&psc=1" target="_blank">https://smile.amazon.com/gp/product/B00O6RJLQC/ref=ppx_yo_dt_b_asin_title_o03__o00_s00?ie=UTF8&psc=1</a></div>
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<div>this one has both a micro-USB and a USB female:</div>
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<div><a rel="noopener noreferrer" shape="rect" href="https://smile.amazon.com/gp/product/B016XI9CZQ/ref=ppx_yo_dt_b_asin_title_o03__o00_s00?ie=UTF8&psc=1" target="_blank">https://smile.amazon.com/gp/product/B016XI9CZQ/ref=ppx_yo_dt_b_asin_title_o03__o00_s00?ie=UTF8&psc=1</a></div>
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<div>it's also branded DROK</div>
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<div>DROK sells a ton of handy modules like this - dc-dc converters of all sizes, I/O, control & display options. I've used them a bunch and haven't been disappointed yet.</div>
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<div>- Carl</div>
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