Retra Pro Max - Accu issue

[Landvogt1893]

Hi,

Today, after a long time, I finally had the chance to test my new Retra Pro Max strobes underwater.

Unfortunately, the excitement didn’t last long. Underwater, one of the two strobes only turned on briefly before shutting down with the message: "Please charge the battery." It turned off immediately after that.

I had charged the batteries (relatively new Eneloop Pros) the day before and only took them out of the charger this morning. When I inserted them and did a quick test, everything seemed fine.

Frustrated, I had to end my dive early.

 

When I placed the batteries back into the charger, it displayed the following values:

• 1.36V – 066mR
• 1.35V – 120mR
• 1.35V – 120mR
• 1.34V – 015mR

After charging for 30 minutes, the values were:

• 1.48V – 066mR
• 1.47V – 120mR
• 1.48V – 120mR
• 1.48V – 015mR

The charger added 141mAh – 184mAh, meaning the batteries were far from empty.

 

Honestly, I’m very disappointed. Even the second Retra Pro Max started showing signs of power loss after just 60 shots.

Is there a solution for this? The Eneloops shouldn’t be defective, right? My Sea&Sea D2 strobes worked perfectly with any battery and never had issues.

I definitely won’t buy the Booster Pack—I'd rather sell the strobes before doing that.

 

Ah, in case it’s important to mention—the water temperature was only 6°C.

 

 

[fruehaufsteher2]

No. One of the envelops is gone. 

[Chris Ross]

7 hours ago, fruehaufsteher2 said:

No. One of the envelops is gone. 

Wondering what are you basing this on? 

 

Generally speaking the voltage displayed by a cell is only part of the story, I would think you would want to know what happens to voltage under load for each of the cells, what sort of load it can produce (in amps) as well as a capacity test before drawing any conclusions.

 

I should add that the larger beam on the retra means that you will use more battery power.  Some back of the envelope calculations show that comparing a 100° beam strobe and a 130° beam strobe, all else being equal the 130° beam needs 1.7 x the lumens to achieve the same lux (to get the same exposure) on a surface assuming the cone shape beam is evenly lit in both cases.  This means 1.7x the battery power is required.  This is the price of a large beam that is evenly filled with photons.  As I recall the Retras used to publicise a 130° beam and the YS-D2 for example was around 100 to 110 or so depending on the diffuser used.  This of course is idealised but should be good for an order of magnitude difference.