|December 1, 2023
Universal lithium ion battery pack, industrial version with outputs 5V to 19V. DC UPS capable
| Useful energy storage 60 watt-hours
PST-MP3500-I with cord and PST-MP3460 add-on pack
| The output
voltage of this unit is DIP-switch selectable. This locks in the voltage. There
is a helpful label on the back of the unit that shows how to adjust the
voltage. This industrial version also has more voltages selectable.
This powerful little battery pack is very flexible, it can act as a 5 volt battery or a 19 volt battery with 14 steps in between. Outputs at 5V , 5.5V , 6V , 6.5V , 7.5V , 8.4V , 9V , 10V , 11V , 12V , 13V , 14V , 15V , 16V , 18V , or19V. It can also be charged with voltages as low as 9 volts and as high as 24VDC.
This portable rechargeable battery pack consists of a 60 watt hour lithium ion battery assembly and two DC/DC converters. The first DC converter allows the pack to be charged with a wide range of voltage inputs. The second allows the pack to deliver a user settable voltage to run equipment requiring 5 volts to 19+volts. All this is built into the sleek black battery case.
For example, this industrial model is used by OEMs to be their battery back-up to add UPS features to their equipment as well as portability. You can run the system from the included charger through the battery pack. When the AC power fails the battery takes over with no interruption in service. This is called a double conversion UPS with DC output.
Special Features :
DC UPS configuration. The power input can be the included AC adapter or any DC voltage between 9V and 24V, such as a car's cigarette lighter power point or solar panel.
This picture is on the back of the unit, showing how to adjust the output voltage:
Typical run time calculations
Voltage versus time discharge curves. You can see that, unlike plain batteries, the output voltage is precisely regulated until the battery runs out of stored energy.
You can see that unlike plain batteries this pack delivers exact regulated voltage until the pack runs out of juice. This is very helpful for instruments, cameras, thermal cameras, lights, and other applications that work best with regulated power. For comparison, most laptop batteries use 14.4 volts and 2.2 AH, so this can run a laptop longer than the built-in battery.
Many laptops can be run at lower voltage than the manufacturer's power pack would indicate, they just can't charge the battery at lower voltages. In this case it is a good idea to run the battery pack at 12 to 14 volts so no power is wasted charging the laptop's internal battery. However, you can't always use this trick, my ACER won't run at all unless I give it the full rated voltage.
Click here to download a quick-start PDF graphic manual that shows how to use these external battery packs.
Questions and Answers
Q: Is it legal to take these spare batteries on airplanes?
A: The PST-MP3500-I has about 3.2 grams of equivalent lithium, and the combination of the PST-MP3500-I and PST-MP3460 contain about 6.4 grams of equivalent lithium, so they are OK to take in carry-on luggage. See the government web page https://www.phmsa.dot.gov/safe-travel/batteries-safe-travel-flyer for more details.
Q: I have a 60 watt laptop, will this 50 watt battery pack work with it?
A: Yes, the 60 watts is the maximum that the computer can use, including charging the internal battery. For the most efficient use of the stored power it is recommended that the PST-MP3500-I be used when the laptop's internal battery is full or removed. Some computers will also run fine on lower voltage (12V, 14, or 16V) which will prevent the internal battery from being charged, if you don't waste energy charging the internal battery you will get you even more run time from the external battery pack. In addition the PST-MP3500-I can supply up to 60 watts when the laptop needs peak power.
Q: The AC charger that is included, is it a peak charger? So that it switches off the charging process when the battery is fully charged?
A: The charging circuit is actually built into the battery case. So the charger that comes with it is just a power supply. In fact any voltage between 9VDC and 24VDC can be used to charge it. The internal charger is a smart charger, it will not overcharge the battery. In fact when I am on a trip I leave the battery connected to the computer and run the "charger" into the battery. That way I only have to bring one power supply with me.
December 2006. I have been using one of these packs since July of 2006, first on a trip to China and then on several smaller trips and also in the lab to create the curves shown above. It was very nice to be able to run my 60 watt Acer laptop as long as I could stand to work on the bus and the plane rides. You can also see the impressive voltage regulation and run time from the curves.
I have also been impressed that it will recharge from voltage sources as low as 9 volts, I have recharged mine at 5 volts, 9 volts, 12-14 volts (car cigarette lighter), at 14, at 16, 19, and even 24 volts. The data sheet now says 9V, because at 5 volts the charge rate is too slow for practical applications. I am sure that it will charge at any voltage above 9V and less than 24V. I have a little solar charger that I would like to try, but my office window faces north toward the mountains and I don't get much direct sun.
I wrote a WordPerfect macro to time how long it took for the computer to shut down due to running low on battery power. Then I ran my Acer a couple of ways to measure how much more time the MP3500-I gives me.
Harry M: I would like to say that this is the BEST UPS appliance I've come across with and I'm very pleased with the product itself. I'm planning to buy more in the near future for other experiments.
Gary Z: I have a Celestron alt-az mount, and use the MP3500I to power it. This battery pack is awesome. I love using it.
Mary L: I have a portable photography set-up to photograph and digitize rare books. I use a MP-3500I to operate the LED floodlights, which require 9V. The steady voltage keeps the light level constant. Sagging illumination was a problem I had with the rechargeable batteries the lights came with.
Mark C: These power supplies have been doing a great job for us for several years now, supplying uninterruptible power to sensitive broadcast equipment. The OEM offered a battery pack but one cant use it and charge it at the same time, so we bought Powerstream's MP3500.