If you're looking for a battery-powered amp that will make your acoustic guitar and vocals stand out at any medium-sized venue (indoor and outdoor), I honestly believe the Fishman Loudbox Mini Charge is the best option. It offers the amazing sound quality of the Fishman Loudbox series (obviously not as full and loud as the larger Artist or Performer amps, but still surprisingly good for its size), with the added benefit of portability. The battery will easily last for a longer show (I've played it for 4 hours straight while busking and it still had plenty of juice). If you add the car charger to your shopping list, you could literally take this amp anywhere you want to go. The on-board effects can add some flavour to your sound, although it doesn't give you a lot of fine-tuning options. Combining this amp with some battery-powered pedals or mixers, however you could broaden your sound and even add more than two instruments to the mix.
It's a bit of a pity that the first input only allows for a jack cable, since I like to send my guitar sound through a DI box that outputs to a balanced XLR – the Loudbox Artist has two multi-purpose inputs that allow for both XLR and jack, no idea why they left that out on this version.
The amp does not only sound great, it looks great too. It is also quite sturdy and can absorb a few shocks while transporting it.
That being said, despite its amazing built there is one MAJOR flaw in my opinion... the location of that battery. Fishman opted for an internal rechargeable lead-acid battery (12V 5Ah). After two years of not using the amp (due to the COVID restrictions on busking in my city), the battery had died. Apparently, this can happen to lead-acid batteries when not used for a long time. I ordered a replacement battery on Amazon quite easily and cheaply, but I was astonished at how hard it was to actually replace it.
There are some rather vague tutorial videos on YouTube on how to do this, but all in all it took me a few hours to get the job done. Replacing the battery requires you to turn loose almost all screws on the sturdy housing, take of the tight-fitting top with all electronics, unplug a few cables, take out the grille and the main speaker... before you can finally access the battery. Piecing it all back together was challenging as well. I have absolutely no idea why Fishman made it so hard to replace a battery that they KNOW is going to die sooner or later (since they offer replacement batteries for this amp on their website). Why didn't they just allow easy access to the battery from the back or bottom of the amp?
Compared to similarly-priced products on the market (e.g. the Bose S1 or Roland Cube Street), the Fishman Loudbox Mini Charge has the best sound in my opinion, but you better hope your battery is going to last a long time.... I have been told that occasionally plugging it in to charge when not using it for a longer time will help prolong its lifespan.