Talentcell Lithium ion Battery Pack NB7102, Rechargeable 17500mAh 64.75Wh Li-ion Power Bank with DC 24/19/5V and USB-C 5/9/12/15/20V Output for Laptop, Notebook, Smartphone, Camera and More

Bought it for my Spark 40 amp. The longest I’ve ever used it was about 4 hours and it’s never even come close to running down.

Charges well

I needed something to extend the battery life of my projector in a spot that has no access to power. Nice to find one in an unusual voltage like this in a nice well though out package.

I purchased this pack to allow portability of my Positive Grid Spark guitar amplifier. The first pack I received either had defective cell(s) or a defective charge/analyze circuit. All led’s of the 4 step led charge indicator would illuminate when the pack was charging, but only 2 or 3 would illuminate when the charger was disconnected from the pack, even after 5 days of charging. Amazon did send out a replacement pack immediately. The new pack displayed a 75% charge upon arrival, I was worried, but after a few hours of charge time all 4 led’s illuminated as expected. I haven’t used the Spark for more than 2 or 3 hours at a time but so far the battery pack has worked great and the portability aspect is great. I’ll update the 3 star rating in a few months after more testing and use. I’m always leery of “unusually named” crappy Chinese lithium battery products and their very optimistic rated vs. actual capacity. LolBy the way, the magnetic phone mounts work great and far better than I expected as an option for mounting the battery.One year later…Replacement pack does not fully charge and dies after adding only 20% charge to my iPhone 14 Pro Max.I maybe have 15-20 hours of use with the Spark amp. Really disappointed. I’ll take it apart eventually and replace the cells.Update….Who cares……This pack, yep #2, is an absolute POS. I’ve made multiple attempts to reach the seller!!!😂😂😂😂Who am I kidding. Great idea, but super crappy execution. I look forward to a proper, tear down and analysis! Ordinarily wouldn’t take the time but I’m almost irritated enough to add it to the list of projects!

I recently purchased a Spark 40 guitar amplifier. Browsing the internet I found many people are using the NB7102 battery to power the amplifier instead of using the A/C power adapter.I purchased an NB7102 battery from Amazon. When I tried to charge it, it didn't seem to be charging. I returned the battery to Amazon and they in turn sent me a new battery. This one appears to be working much better. The amplifier works great with the NB7102 battery. I have not used it enough to tell for sure, but other people report the battery lasting 4-6 hours on a charge while using the Spark amplifier.The people at Talentcell reached out to me to make sure my return was being handled properly. They also gave me tips on charging, and using the battery indicator button. I am very please with their response, and will make future purchases from the company.

So far so good. Get good playing time on my amp. We will see how long it's life service is. I'm happy with it.Update.... I fully charged the battery. When I went to take it on a trip the battery had dropped to half without me using it. This doesn't seem right. Should stay charged when not in use.

I use the product for my Spark amp. It does what it needs to do and lasts for days. For reference, i use the amp for about 30-45 minutes each day. I don't need to recharge for about a week. Even when I do need to recharge, I only need to recharge it for a short amount of time before it's back at full charge.

I used this battery to power my Spark 40 guitar amp, but it has quit taking a charge. Great while it lasted, but I expected a long life! I held off posting a review hoping it would come back to life, but no luck.Update: The manufacturer is sending me a replacement - I couldn't ask for better service. I'm changing my rating to 5 stars. Good company!