Buggy For Emergency Power?

[yurtle]

After watching Puerto Rico's power woes, I thought about this.

If I lose power for an extended time, I would unplug my DPI, but if I'm out of town, would the DPI discharge the batteries if left on float without power?

Second question. My Dell Inspiron 15 7559 laptop has a charger that is 120 VAC to 19.5 volts DC @ 6.7 amps output. Sure I can use an inverter to get 120 volts, but using a somewhat inefficient inverter to step up to 120 VAC, then another switcher to step down the 120 VAC to 19.5 VDC seems like a waste, given both have heat sinks.

Does anyone know if a laptop could be safely run on +/- 18 volts? At full charge, 3 - 6 volt batteries would be at 19.11 volts, but over time would slowly discharge. I can easily charge my phone with my USB adapter, and can tether it to get internet on my laptop. I know, why not just use my smart phone instead of the laptop. Well, I just like a full sized keyboard.

thanks

[BobBoyce]

Originally Posted by yurtle

After watching Puerto Rico's power woes, I thought about this.

If I lose power for an extended time, I would unplug my DPI, but if I'm out of town, would the DPI discharge the batteries if left on float without power?

Second question. My Dell Inspiron 15 7559 laptop has a charger that is 120 VAC to 19.5 volts DC @ 6.7 amps output. Sure I can use an inverter to get 120 volts, but using a somewhat inefficient inverter to step up to 120 VAC, then another switcher to step down the 120 VAC to 19.5 VDC seems like a waste, given both have heat sinks.

Does anyone know if a laptop could be safely run on +/- 18 volts? At full charge, 3 - 6 volt batteries would be at 19.11 volts, but over time would slowly discharge. I can easily charge my phone with my USB adapter, and can tether it to get internet on my laptop. I know, why not just use my smart phone instead of the laptop. Well, I just like a full sized keyboard.

thanks

I would go with a decent 48V true sinewave inverter that runs from the entire pack. By using a true sinewave inverter, you avoid the 20% losses caused by running equipment that requres sinewave power on a modified sinewave inverter. The true sinewave inverter costs more, but you can use it to power a fridge, or your computer, ect. in an emergency. A 48V inverter is more efficient than a 12V inverter.

[yurtle]

Originally Posted by BobBoyce

I would go with a decent 48V true sinewave inverter that runs from the entire pack. By using a true sinewave inverter, you avoid the 20% losses caused by running equipment that requres sinewave power on a modified sinewave inverter. The true sinewave inverter costs more, but you can use it to power a fridge, or your computer, ect. in an emergency. A 48V inverter is more efficient than a 12V inverter.

My laptop works fine on a 120 volt square wave interter. It is then fed to a 120 to 19.5 volt switching power supply. Super stupid for powering a DC source.

Again, this an "end of the world" situation, not a daily/monthly/yearly/etc. event. I don't need food, fridge, water, etc. That's all taken care of. I just wanna be able to power a laptop, but if that ain't possible, I gots me a smart phone. That will only work as long as the cell towers can get backup diesel for their gennies. Most diesel will go to hospitals, water and sewer treatment plants, dialysis clinics, etc. I used to be in the biz.

[LVCJ]

Originally Posted by yurtle

My laptop works fine on a 120 volt square wave interter. It is then fed to a 120 to 19.5 volt switching power supply. Super stupid for powering a DC source.

Again, this an "end of the world" situation, not a daily/monthly/yearly/etc. event. I don't need food, fridge, water, etc. That's all taken care of. I just wanna be able to power a laptop, but if that ain't possible, I gots me a smart phone. That will only work as long as the cell towers can get backup diesel for their gennies. Most diesel will go to hospitals, water and sewer treatment plants, dialysis clinics, etc. I used to be in the biz.

Nice idea but I wonder why you would need a laptop in a true "end of the world" senerio?
Especially since chances are there would be no wifi/Internet anyway.

[JohnnieB]

Originally Posted by yurtle

After watching Puerto Rico's power woes, I thought about this.

If I lose power for an extended time, I would unplug my DPI, but if I'm out of town, would the DPI discharge the batteries if left on float without power?

-----------------------

Without AC power, the DPI won't be in Float charge mode.

The battery discharge rate of a powered down DPI would be the reverse biased leakage current through a pair of SCR's, so it wouldn't be very much. Probably far less than the self-discharge rate of the batteries themselves.

DPI doesn't mask the part# on the SCR's, so you can look up the reverse leakage, or stick an ammeter in the charging loop and measure it.

As for the other stuff, I don't know, I use a gasoline powered inverter type generator to power critical electrical stuff during power outages and keep enough fuel on-hand for 2-3 weeks of operation.

[yurtle]

Yeah. I don't have a generator, and when I lived on the Georgia coast, during hurricane/tropical storm outages, there were none to be found.

Just bored pondering. I still may try my laptop on pure 18 +/- DC, once it's beyond its useful life. Hate to kill a gaming machine that's only a couple of years old.

[BobBoyce]

Originally Posted by yurtle

Yeah. I don't have a generator, and when I lived on the Georgia coast, during hurricane/tropical storm outages, there were none to be found.

Just bored pondering. I still may try my laptop on pure 18 +/- DC, once it's beyond its useful life. Hate to kill a gaming machine that's only a couple of years old.

You would be much better off using an isolated power supply. What you desire to do carries extreme risks for the laptop. If the cart ground ever gets connected to hot or ground, and an accessory or grounded connection on the laptop comes in contact with something grounded to the frame, your laptop will be toast. We had a few people that were hacking their controller programming do damage to their computers by allowing unknown ground loops to occur with their computers and carts. It was mostly laptops that this happened to because manufacturers do not isolate ports on laptops from the electrical ground of the power input.

[yurtle]

Yeah. It was much easier back in the old day when AC could vary +/- 10% and everything would be fine. In fact, 110 was the norm in my neck of the woods. Over decades it incrementally crept up to 120.

Luckily, my smart phone has a USB female adapter, so I may be able to use a real keyboard with it. Never tried, as I don't have one.

My cable modem would have to be powered by 12 volts DC, and can be a backup wifi to my phone's 4G, which depends on their diesel generator backup.

[BobBoyce]

Originally Posted by yurtle

Yeah. It was much easier back in the old day when AC could vary +/- 10% and everything would be fine. In fact, 110 was the norm in my neck of the woods. Over decades it incrementally crept up to 120.

Luckily, my smart phone has a USB female adapter, so I may be able to use a real keyboard with it. Never tried, as I don't have one.

My cable modem would have to be powered by 12 volts DC, and can be a backup wifi to my phone's 4G, which depends on their diesel generator backup.

So true. The power outages after the hurricanes were bad enough, but as the backup generators that supplied network services, cellphone towers, and other infrastructure began running out of fuel... The house of cards collapsed. Those in charge had decided that since most power outages are short term, they failed to take long term outages into consideration when planning their backup power systems.

I've not relied on grid power in decades. I feel that is better than relying on it, then trying to compensate when it goes down. I find myself timing my use of power so I can use more mostly when the power system batteries are fully charged and there is excess power to use. I charge my RXV during that time.

[yurtle]

I have a paper library, which my son - 27 - makes fun of. In the event I have to survive for a while on my own, I'm covered.

I got an old school hand crank megger, that I can charge a cell and maybe a laptop from, with a little circuitry. I also have a '94 Accura, which I can cannibalize to rig up a bicycle and alternator...

I think I'm drifting off topic, into the crazy survivalist mode. I was really just thinking about weeks or months. Puerto Rico is beyond that.