I was contacted a while back by the good people at XTAR, a company producing new rechargeable high capacity lithium batteries. They wanted feedback from people like me that go through a lot of batteries for my job.
I used to use single use Energizer lithium batteries because of the fact that I could depend on them lasting a whole 12 hour day in my wireless mics, which at the time was Lectrosonics SMQVs (requiring two AA batteries) at 100mW transmission power.
But times have changed, and the restructuring of the wireless spectrum by the FCC back in 2020 meant that I needed to get new wireless mics, because my beloved SMQVs were single block transmitters, and I now needed wide band transmitters so that I could be more versatile as the wireless spectrum could vary wildly depending upon the location I am working in.
After a couple of trials I ended up going with Wisycom because I was impressed with their ultra wide band capabilities, as well as the various steps in transmission power, and ability to pack a lot of channels into a small amount of spectrum if needed. Not to mention the sound quality and exceptional range.
So I got my first four transmitters, which were the MTP40s dual battery versions. Because I could get roughly the same range at 20mW as my old Lectros at 100mW, that meant that the power consumption of the transmitters was actually a lot less. And with the rising prices of single use lithium batteries, I decided to explore rechargeable options.
So I went with black Eneloop Pros because a lot of people in my industry recommended them on various forums and online groups. And to be honest, I’ve been pretty happy with them, though they don’t hold their charge very well if they’ve been lying around unused after a new charge.
Not long after my first four Wisycoms were being put to use, was the release of a new line of transmitters, the MTP60. So I ordered a set of four of those to square out my package with a full eight channels. However what I noticed is that the MTP60’s were struggling with giving me an accurate readout of the telemetry, and my batteries, even Energizer lithiums, would jump down to displaying a low charge rather quickly, which, in the heat of a job, would cause me to panic and change batteries out quite often. I didn’t realize that it was the readout and not the batteries themselves. After testing I had found that a newly charged set of batteries would go from 100% charge to 0% very fast, but would hang on that 0% for about as long as the battery should actually last. Needless to say, that didn’t help my anxiety. So I’ve mostly been using the MTP40s’ on my jobs, as their telemetry readout is much more accurate, and most of my jobs have required four wireless or less in the past few years.
But this isn’t a history in my experience with Wisycom so much so as it is a background to give you context with my findings with XTAR batteries with my Wisycom transmitters.
So like I mentioned before, the folks at XTAR wanted my feedback on their batteries in my equipment. Naturally I was happy to oblige.
They sent me eight 2700 mAh 1.5V (AA CLR 4300) rechargeable lithium batteries, and eight 3000 mAh 1.5V USB-C (AA LR 3000 USB-C) rechargeable lithium batteries (complete with multi USB-C breakout cables), and an eight bay charger, the L8 Pro.
I’d first like to point out that the eight bay charger is really compact, compared to other chargers that I have. This is great for traveling or if you are building out a charging case. It is powered via USB-C, and comes with a cable, but no charging block. The only USB-C charging block that I currently have is for my cell phone, so they have to take turns.
I tried charging the LR 3000 USB-C with their breakout cable, but I found that, although it is an interesting idea, I can see myself not wanting to fiddle with the delicate connectors in the heat of battle. Charging them with the dedicated charger is a lot more streamlined for my workflow.
Charging time for both types of batteries seems to be quicker than my Eneloops in their charger, but by how much I don’t know, I haven’t timed them out.
But how do the batteries perform? Well this is where I have to apologize to XTAR for taking so long to come up with my results. It seems that finding a day to run 12+ hour tests is harder than it seems. And I wanted to do multiple tests to be sure about my findings.
So since these are lithium batteries, I ran them with the transmitters in Lithium mode. But I was also told I should try Alkaline mode, since these batteries apparently don’t quite behave like single use lithiums. XTAR shared a lot of technical information with me on how their different batteries behave, and without going into those details myself (you can see that information complete with graphs on their web site), I will just share a rundown on how they behaved with my equipment.
All tests were run at 20mW transmission power.
Lithium Mode:
MTP40s 2700 mAh 1.5V (AA CLR 4300)
100%@11h, dropping a step every 20min over the next 2h. Total ≈ 13h with medium drop off.
MTP40s 3000 mAh 1.5V USB-C (AA LR 3000 USB-C)
100%@6h, drops step every 20min for 6h, hangs on at 12% for 3h. Total ≈15h with long tapered drop off.
MTP60 2700 mAh 1.5V (AA CLR 4300)
100%@1h, dropping a step every 1-1.5h for 10h. Total ≈ 11h w/long drop off.
MTP60 3000 mAh 1.5V USB-C (AA LR 3000 USB-C)
Unit would not power up.
Alkaline Mode:
MTP40s 2700 mAh 1.5V (AA CLR 4300)
100%@14h, dropping a step every 20min over the next two hours. Total ≈ 18h w/steep drop off.
MTP40s 3000 mAh 1.5V USB-C (AA LR 3000 USB-C)
100%@8h, 87%@3.5h, 75%@1h, 62%@1h, dropping a step every 20min for the next 2h, hanging on at 25% for the next 3h or so. Total ≈ 18h with long tapered drop off.
MTP60 2700 mAh 1.5V (AA CLR 4300)
100%@1/2h, 90%@9h, dropping 10% every 20min for two hours. Total ≈ 12h w/ medium decline after holding high charge for 9.5h.
MTP60 3000 mAh 1.5V USB-C (AA LR 3000 USB-C)
Unit would not power up.
Conclusion:
In both tests, the MTP40s 2700 mAh 1.5V (AA CLR 4300) lasted an extremely long time at full capacity before taking a couple hours to run down. A quicker drop off might lead to the batteries dying before you notice them losing their charge, as we are used to with single use lithiums. But I still feel that there is enough grace period while the charge declines to notice and predict easily.
The MTP40s 3000 mAh 1.5V USB-C (AA LR 3000 USB-C) lasted just as long but with a more steady drop off, which could be helpful in being able to foresee when the batteries will need to be changed.
The MTP60 2700 mAh 1.5V (AA CLR 4300) held onto their charge pretty well for a long period of time before having a reasonable drop off in charge. It would seem that the MTP60 is a bit more power hungry than the MTP40s.
And in both cases the MTP60 3000 mAh 1.5V USB-C (AA LR 3000 USB-C) the unit would not power up.
According to Karl Winkler at Lectrosonics, he cautions people not to use 3000mAh batteries in their transmitters, and although they worked fine in the MTP40s’, the MTP60’s don’t seem to like them.
So my takeaway is that for MTP40s’ either battery works fine, and you’ll get a similar duration of charge, just with different readout results. But for the MTP60, stick with the 2700mAh versions. Either way these are impressive results for rechargeable batteries. The only thing that remains to be seen is how long the batteries last over time. I’ve read what XTAR says, but how they actually perform will take time know for sure.
That said, I’d like to thank XTAR for trusting me with your products and allowing me to test them out for you. And again I apologize for taking so long in getting this review done.