Talentcell 24V Lithium ion Battery PB240B1, Rechargeable 42980mAh 156Wh Li-ion Batteries Pack with DC 24V/12 Volt and 5V USB Output for LED Light Strip, CCTV Camera, Smartphone and More

What I liked about this battery:1. physical on/off switch prevents parasitic drain, so the battery stays charged when not used.2. dual voltage out, 12v regulated and direct pack voltage tap of 29.4-21v eliminates conversion inefficiency for 24v CPAPs. 12v still is bucked down to a regulated 12, but it's still quite efficient.3. the form factor is great, about the size of three iphones stacked.4. Standard 5.5x2.1mm in/out plug takes standard DC connectors.5. BMS successfully prevented over charge and over discharge.6. Actual measured capacity over five nights of use was 134.2 watt hours. From a 156wh stated capacity, getting within 20 watt hours of stated capacity was acceptable at 86% of stated capacity under load. I call that a success.7. The battery comes with a matched charger that works well and charges slowly. Slow charging means better saturation and longer cell life.What could be improved:1. The 12v out plug is an oddball size, but the included adapter cable converts to 5.5x2.1, but the adapter cable has a male at the other end, necessitating bringing a Female to Female Power Jack Barrel Adapter to convert to what the DreamStation cable needs. I expect that the mfr had to use a different standard to reduce user error. Putting a female end on the jumper cable would be a simple, no-cost fix.2. The LED indicator lights still had two bars lit when less than one night's sleep remained on the pack. Having the LED lights map better to state of charge would help the user know how much is left. Better yet would be a push button activated volt meter instead of the vague bars that don't provide actionable data.Sleep testing for this battery. Note all tests conducted with no humidifier, tube heating off, airplane mode to minimize power demand.Night 1. ResMed AirMini with direct 24v cable. 19.7wh for 7.75 hours of actual sleep. This works out to an estimated 20.3 wh per 8 hour night. Start voltage 29.0, finish voltage 28.35.Night 2. Philips DreamStation with direct 12v cable. 25.8wh for 7.9 hours of actual sleep. This works out to an estimated 26.24 wh per 8 hour night. Start voltage 28.2, finish voltage 26.8.Night 3. ResMed AirSense 10 with direct 24v cable. 33.8wh for 8.6 hours of actual sleep. This works out to an estimated 31.44 wh per 8 hour night. Start voltage 26.97, finish voltage 25.37v.Night 4. ResMed AirSense 10 with direct 24v cable. 34.1wh for 7.63 hours of actual sleep. This works out to an estimated 35.76wh per 8 hour night. Start voltage 25.38, finish voltage 23.07v.Night 5. ResMed AirSense 10 with direct 24v cable. Start voltage 23.42. Battery self-protection circuit cut off the power at 4.6 hours into sleep. Partial night est consumption 20.83wh.My final analysis is that this is an excellent battery system that is well matched to the DreamStation, AirMini and AirSense 10 CPAP machines when additional precautions are taken to minimize power draw. I removed humidifiers, turned off tube heating and put them all in airplane mode. I'm completely confident that I can take any of these CPAP machines camping with only this battery and reliably get 3-4 nights of use without worry between recharges.Solid product, well done.

I got this to serve as a UPS for my modem, router and Yolink hub. I leave this with the charger constantly connected to the 24 volt socket, the modem and router connected to the 12 volt socket ( a constant 11.8 volt by my meter) and the hub connected to the USB socket. I fully charged the battery and then left everything running with the charger disconnected. I measured the current at 12 and 5 volts and the full load on the battery was 16 watts. At the start, the 24 volt connection showed 28.6 volts, and this declined slowly. After 9 hrs 45 mins, the last bar went out on the battery, and the 24 volt connection was at 20.5, so I reconnected the charger. That is exactly how long it should have lasted, since it is rated at 156 watt-hours (16 watt x 9.75 hrs). So, if I have a power outage, my network will stay up for almost 10 hours, and if power is restored earlier, the battery starts recharging, and there is no interruption in network service. I expect, though I haven't tested this, is that if no one is here and the power goes out for over 10 hours and the battery shuts down, it should come back on when power is restored, and also start recharging the battery.It would be better if the unit beeped when the battery was almost exhausted, so I could shut things down in a controlled manner before the power cut out. But overall, this unit works very well for this sort of application, and is much cheaper than any regular UPS with a comparable watt-hour capacity. I wish TalentCell offered this type of system with their larger capacity LiFePO4 batteries.Those who need 24 volts should realize this is NOT a regulated voltage (like the 12 volt output), but whatever the battery potential is at. This will vary from 28 to 20 volts as the battery discharges-all batteries drop in voltage as they discharge. If your "24 volt" device can't handle that variation, consider getting a 24 volt buck/boost voltage regulator.I tested it again after 9 months use, with two PB240B1's connected in parallel, and the power was sustained for 19 hours-see graph. Very good performance.And a year after the purchase, the two batteries kept my system running for 19 hours. I keep it "charged" all the time with a 4 amp charger that maintains 29.2 v. I am happy that it has retained this much capacity after a year.

We use these to power up equipment that is being worked on. They need 24v to power up the PLC and also disengage the motor break when the equipment needs to be moved around.We have some other units that allow multiple voltage outputs. If someone isn't paying attention and they do a long press instead of a short press when trying to turn the battery on, they will accidentally feed the wrong voltage into the machine. I've been called over multiple times when people can't figure out why the machine isn't working when they plug in the battery.This battery pack solves all of that. It only puts out 24v which is the only voltage we need. It's idiot proof so you can't fry anything with the wrong voltage. I personally also love that is has a switch, it will set there and put out 24v all day long no matter how small the load is. You don't have to worry about it powering itself down if the idle current on your load is super small.For me that is a plus, but Apparently it's too difficult for some people to remember to turn the battery pack off when they are finished using it. Because this device lacks the smarts to turn itself off, it's up to the operator. On several occasions I have went to go use the battery and found it setting in it's storage location, totally dead with the power switch still on.You'll have to decide what is more important for your use case. Do you want a battery that shuts itself off, or do you only want it to shut off if you turn it off. That will help determine whether this battery pack is right for you.