Talentcell24V 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.

This battery pack and charger work very well. One charge lasts for a long time, and provides plenty of power for cell phones and small electronic devices. Worth the money.

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.

I am updating my original 1 star review because their customer service was incredible. I started having issues, and we came to the conclusion that I believe I was using the wrong charger. If you read their pictures, you have to make sure you’re using the right type of charger. Nonetheless, I called the number on the account and no one answered so I just figured I would never get to or get it resolved because the number was weird. Next thing I know I got a text, couple hours after someone following up with a reason for my call. Next thing I know they had a new one in the mail shipped to my house. Wow. I feel like you don’t get customer service like that anymore.

I bought this battery in Nov 2021. When i received it I noticed that out of 4 lights indicating how much the battery is charged only 2 were working. I put the battery to charge, but no matter how long i charged it there were only 2 lights working out of 4. However i did not do anything with it as I did not use the battery till February. February i used this battery for about one hour to set up the station for which it was designated and pilot how all this is working. The battery was working. I put this to charge over night. After few days when i actually needed to perform the battery did not work anymore and no matter how much i would charge them it was not working and there were no lights .I wrote to the company 5 days ago telling them the situation but till now no answer.