Arris 18-24 hour backup battery for TM822G TM802G TM722G TM702G BPD066H

I purchased to back up my phone during power outages so thought I would have phone. As another reviewer pointed out if you don't have an old fashion phone connected directly into modem or house jack and only a portable phone you still won't have phone since the cable company uses electric to push their services onto your modem. Also read reviews for arris modems some folks said they never could get voice to work on them. That was my case I bought per internet provider saying an arris TM822 was compatible and then bought this back up battery along with an old fashion phone to have service during the many black outs we get. Well they never could get the phone part of the arris modem to work for voice thus I didn't need the battery. Also was told, at least by my provider, this battery won't help you since they push voice over cable lines via electric off a pole only 5 houses from mine. So in all probability if power is out at my place it is out for voice over cable and thus the battery won't help since the service will be down. I would suggest that you figure out if the Arris modem works and if your provider has power farther from your house source so you may benefit from a backup battery. I bought the battery being naïve and it did fit well but in the end due to the modem not working right I had to return it. It cost me $20 for the battery and $11 to return it! Also it never did show it was charging when inserted into modem. When mentioned to the company to see if they would reimburse the shipping they said it will only charge if the voice part of modem is functioning. I don't believe you will gain anything from having a back up battery just hope your cell phone will work!

Easy to install. Simple connectiveness with Sparklight phone modem. Works with AT&T older corded princess phone in power outages.

I bought this as a backup battery never expecting it to really be put to use but rather as a little peace-of-mind. However, 2 weeks after installation it was tested when mother nature knocked out the power to my area for 17 hours.The back-up battery worked flawlessly helping me make phone calls to the electric company to report the outage. The only downside was the fact that Xfinity (Comcast) has a signal amplifier that has batteries in it that didn't last as long as mine. When they came by and put a generator on their amp I too was up again running on my backup battery.PROS:- Long-life backup battery- Maintains the phone connection at my end for network communicationsCONS:- When the 3 car-sized batteries in the amplifier for the node fail it won't matter if your unit works or not, you will lose connection until utility switches battery or supplies a generator

Put this in a while back and had an extremely unusual power failure that ran for nearly 24 hours. This backup battery kept phone service working with the cable modem for the duration. If your phone requires a wall wart to work beyond a very limited mode, this won't power it and you need at least one PSTN type Touch-tone phone that doesn't require its own wall wart, or one that has its own backup batteries, to at least minimally function. The cable modem can power the ringer, dial tone and the DTMF Touch-tones.If you're expecting this to power the entire modem, it won't. You won't be able to surf the Internet. Arris modem backup batteries are only designed to maintain the telephone portion of the modem to enable emergency phone calls. If you think about it, that's as it should be, so that the battery is conserved to provide phone service for as long as possible.

2018/05/22: It's been running a few days now. As a quick test, I pulled the power on the modem and verified my home phone still had a dial tone and could make a call. Worked perfectly. The real test will come next time I lose power. So far, so good.2018/05/20: I bought the Arris TM822R modem on Amazon. According to a battery spreadsheet on the Arris website, this battery should work with it.Other reviews and questions/answers say it doesn't work with the TM822R, but I took a chance and bought it anyway. It didn't look like it would fit as the battery release is on the opposite end, but it snapped in, feels secure, and the battery LED lit up green. I'll test after it goes through its charge/discharge cycle and update with the results.

Purchase forARRIS Surfboard Docsis 8X4 Cable Modem / Telephone Certified for XFINITY - Download Speed: 343 Mbps (TM822R)My only use for this is the telephone portion. I already have a Arris cable modem. I needed a point near a phone jack which I made with a split in the attic. Then I needed this to cover me through brownouts, black outs, power loss due to storms and hurricanes. This is the largest backup battery made for my device. I've tested power loss, by just pulling the plug. Left it for about 12 hours and it was still okay. Mind I didn't have a lot of call during this, but I did have some.

I had ordered this battery for my modem. Unfortunately it didn't fit. But they were gracious enough to refund my money. Great customer service.

This is the backup battery for the Arris cable modem. When the power is out, I can still place a telephone call through the modem just like the old land line phones. The phone can't be a cordless phone, just a regular land line phone.