Jerry Diver

Retra strobe with the battery pack is the same length as a Backscatter miniflash, see below screenshot from their video of the new battery pack where the guy compares it in length. With the battery pack are nowhere near the weight(!) or bulk of larger strobes from Ikelite, Seacam, etc. The protruding battery pack is a very nice handle to position the strobe and a welcome addition in length IMHO. I didn't like that hey shortened the length with the new Booster.

I've gotten at least three emails from Retra for each of their product launches. Show me another underwater strobe where I can choose either 4xAA, 8xAA or a proprietary battery pack... I feel like we should start a whole different topic where we just complain about high prices for just about anything in underwater photography. I have some ideas for starters. Fiber optic cables that probably cost $10 in material, now available at $95: null And what about those trigger boards that cost $20 in electronics, yours for just $695: null

Both batteries need to be replaced so it's $50 and the lifespan in underwater strobe usage is already much less, probably around 150-200 cycles until we reach 60-70% battery health, because underwater strobe battery usage is the exact opposite of ideal battery usage with sharp spikes in battery drain for fast recycle time. Therefore an additional 40% decrease in battery life is a substantial problem and as a result a well tuned battery pack will eventually cost less. The best I can explain is by comparing it to an engine with 2 or more cylinders (battery cells). If one cylinder works perfectly until 4.000 rpm and the others are good to 6.000 rpm we should limit the rpm to 4.000 rpm. However we can't know this unless we measure all cylinders for wear (internal resistance). If we are constantly running the engine at 5.000 rpm the weaker cylinder will get used more and the stronger cylinders too because they will need to work harder to push the weaker cylinder which is producing much more friction and heat. Eventually all cylinders will add friction and simply stop working, turning over, which is the best case. The worst case is the engine has a failure at high rpm (reverse polarity within the battery). Internal protection circuits help reduce this to an extent but if there is a high enough difference the stronger batteries will damage the protection circuit of the weaker battery and itself. Again, the reputable topside strobe brands never combine two or more loose Li-Ion cells (especially not the powerful 21700) and imagine the pressure they have in a much larger market, the ones who would do it would immediately gain an advantage over their competitors. So why don't they do it? Answer is: it presents too big of a risk for them to open their battery compartment to accept large loose Li-Ion batteries and even if the manual says you can only use such and such batteries you have invited users to insert anything they want and the product can't effectively prevent the damage. Yikes, I guess the 30-40% failure rate of the backscatter miniflash was even higher.

It's about measuring how each individual battery performs and then combining them. Constantly using the same pair of batteries together could actually be worse.

https://www.sciencedirect.com/science/article/abs/pii/S0378775313019447

Backscatter is primarily a sales operation, not a strobe manufacturer. Their products are made in Chinese factories and imported to the USA at low costs. They rarely repair products because it’s cheaper to replace them—a Miniflash costs them around $100, and the new HF strobe about $200 directly from the manufacturer. Their Miniflash had a high failure rate (30-40%), but they kept customers semi-satisfied by sending out new units, which only makes sense given the low purchase prices. This approach appeals to consumers who focus solely on price and specs, ignoring the bigger picture. In contrast, companies like Ikelite and Retra manufacture their products in-house, in the USA and Europe, where labor and environmental laws actually apply. One is a powerhouse in longevity, and the other is a true innovator. To my knowledge, Retra is still the only company with a leakage detector in the battery compartment and firmware updates via mobile phone. Personally, I don't need these features, but for some, they are an absolute must-have. There are many strobe options now, so you can choose according to your budget and needs. However, be aware that shiny low prices usually result from cutting corners in areas that might not be obvious when looking at a spec sheet.

Thank you, I have corrected my text.

Already explained in the topic about the HF1, a brief recap: more than one battery requires careful monitoring of discharging as the electrical properties of batteries are always dissimilar and would start damaging each other if not controlled, especially lithiums. There is no "dry" strobe manufacturer, except Yongnuo YN560Li (2x 18650), that does such a thing as combining more than one loose lithium battery in their products. It's either Nimh or proprietary battery pack. This "trend" is completely unique to the new brands in underwater strobe market that want to blow up their spec sheet at minimal cost.

Just examined the battery packs on offer at Backscatter's website: Ikelite battery pack: proprietary batteries with proprietary charger 21.6Wh at $250 or $11.6 per Wh Keldan battery pack: proprietary batteries with proprietary charger 49Wh at $430 or $8.8 per Wh OneUW battery pack : proprietary batteries with proprietary charger 14.6Wh at $185 or $12.7 per Wh Seacam battery pack: proprietary batteries with proprietary charger 14.7Wh at $381 or $25.9 per Wh Retra battery pack: proprietary batteries with integrated USB-C charging 40Wh at $399 or $10 per Wh (when pre-order sale finishes $11.2 per Wh) Honestly, I don't understand the complaints about the pricing. It aligns with what other manufacturers charge for their proprietary battery packs. However, there is a significant difference, in my opinion: Retra is the only company offering their pack with a standard USB-C charging port. Additionally, the strobe can still use 4xAA or 8xAA batteries if an airline bans lithium batteries for any reason.

The miniflash uses a single Li-Ion cell. This is a huge difference to using multiple cells combined together.

This is absolutely the worst solution Retra could have done and I am glad they actually developed their own battery pack to ensure the safety of their users. Opening a battery compartment of a underwater strobe to multiple loose Li-Ion cells is a recipe for disaster. There is not a single reputable land strobe manufacturer who does this, there are either NiMh cells or proprietary Li-Ion battery packs. The use of multiple loose Li-Ion cells in underwater strobes is driven purely by cheap manufactures who want to increase the numbers on their spec sheet at minimal cost and at high risk for the user.

I'm glad Retra hasn't gone the easy and cheap route of opening their battery compartment to loose Iithium cells. I choose an "expensive" battery pack over loose lithium cells any day. Additionally I can go back to using 4xAA or 8xAA if any airline decides to ban lithiums...

This is perhaps my personal preference but the new Booster design is way too short... I couldn't use it as a handle to manoeuvre the strobes the same way as I could the first generation Booster which was about twice the length. The added length is a welcome addition, in my opinion. And looking at the spec sheet it looks the buoyancy is substantially improved as well. With the battery pack the strobe is now practically neutral without adding dry weight. It's the same length as the Backscatter Mini Flash, here is a clip from the hands-on video: null

$ per Wh is the same or currently even better when compared with the AA configuration: - 8xAA + Booster + chargers have around 20-22Wh and cost about $250 or $11-12 per Wh. - Battery pack has 40Wh and is currently $400 which is $10 per Wh. Potato patato... I choose the battery pack any day of the week for the practical charging, consistent performance and no more chasing loose cells on the floor and underneath furniture! Recycle time with these strobes on 8xAA is already not an issue and honestly I don't feel like deep frying the pupils of any marine life with my strobes, no thanks.

We can buy off-the-shelf batteries at a low price, but it's not as simple or cheap to make a safe and durable battery pack with multiple cells. When done right, each cell is measured for internal resistance and paired with similar ones. Off-the-shelf batteries don’t provide this info, but it’s crucial when combining cells. A battery pack should "die" when one cell fails, which makes it safer than the alternatives. I completely agree that proprietary battery packs are more expensive in many ways, but in my vie the cost is small compared to the potential risks of carrying high-capacity loose Li-ion cells and charging them on liveaboards, etc.