Are they reliable? Is there a different one I haven’t listed here that you would recommend? We are looking for cheaper option compared to the ones listed on AndyMark.
The thing that kills you with batteries is the shipping costs, so those Amazon batteries are significantly cheaper than MK. Definitely worth trying out for non-competition use.
However, I agree that it’s not worth cheaping out for competition batteries, and the equipment to adequately test off-brand batteries isn’t cheap either, and I’d be more worried about consistency with cheaper batteries.
If I were trying to save batteries costs for a team, I would buy fewer batteries rather than lower quality ones. I believe the average team only needs can make do with four batteries for competition, and anything more than six is overkill IMO.
I wouldn’t recommend a CA team trying to make a playoff run roll in with anything under 10 (1/qual match then cycle back through for playoffs), and an alliance captain should be looking at 12-14 (…to cover for the average team that brought 6).
This assumes that CA team is already running brushless swerve at an aggressive gearing for their weight, which is the biggest power draw by a significant margin compared to anything with decent engineering on the superstructure. We use the whole battery.
A team bringing a standard geared kitbot on a pair of cims will be fine with four to six. That robot wont use an entire battery every match.
Hmm, yeah perhaps I’m underestimating this need given that we’ve never made a deep playoff run, and our robots have generally not been super power intensive.
What’s actually nice is that even the new “long road” is shorter than going best-of-3 in Quarters, Semis, and Finals which drove our “3[quarters]+3[semis]+3[finals]+1[spare]=10 batteries for Playoffs” math for many years.
The maximum number of matches in playoffs without replays is 8 (if you lose the first round and then play 3 finals matches).
I guess where the numbers are differing is that the average team doesn’t discharge their batteries all the way each match, and also can recharge batteries used in the morning for later matches that day, or even use not fully charged batteries with only a slight drop in on-field performance.
To move the thread back to the original topic, do you think it would be worth gambling on off brand batteries vs buying fewer MKs? I suppose the other possible tradeoff is using our older MK batteries or using newer offbrand batteries?
Through our pretty informal testing they do not have any significant performance difference compared to our MK batteries but this would need to be validated through a CBA.
It was from Amazon and at the time the price seemed too good to be true (something like $36 shipped). That battery is going into our competition rotation since one of our MK batteries puked out its guts last weekend.
Out of curiosity, does the battery have any sort of date/SN stamped on it (I know our MK batteries do). With Amazon, I’m always worried about them mixing stock between different distributors, but the distributor for some of the listings I’m seeing (“AAA Security Depot”) is an official Powersonic distributor so it should theoretically be fine.
The practical concern would be getting an old battery that’s sat on the shelf for a long time.
The Powersonic I tested did come from AAA Security Depot, from Miami IIRC. It currently has our usual competition battery number label stuck squarely over the lot number.
FWIW - We (the OP’s team) did end up buying 6 PowerSonic from Amazon after seeing them recommended as a good budget option by a few different people in this and other threads. They all work great! We will be taking them to our week 4 Iowa Regional.
