batteries

[bvanant]

There is a good article on the underwater photography guide (bluewater photo) that confirms my approach
NiMh high capacity batteries combined with a good fast charger are the best
I use annsmann 2850 mah with their fan cooled charger and it works great
Eneloop are better suited to the camera itself than the strobe

I guess since I wrote the article, I can make a couple of comments. The new Eneloop XX batteries are very very nice. High enough capacity and very low internal discharge. Secondly, I don't think there are any GOOD, FAST chargers. You should always charge at no more than .5 capacity i.e. for a 2000 maH battery charge at no more than 1000 mA and better than that at 500 mA. I think that the LaCrosse battery chargers are very very nice and use them all the time at home, while for travel, I use the white MAHA charger that does 4 batteries at a time. Fast charging (30 minutes or less) can really cause significant lifetime issues with batteries.
Bill

 

[Interceptor121]

Bill I think your article is great and I had not noticed we now have eneloop at 2500 mAh that obviously sounds very interesting as they are even cheaper than the 2850 I used to have
However on charging I dare to disagree. Low current is probably the safest method however circuit controlled charger can pump much more current in the batteries and having used an Ansmann Digital Ultra4 for 4 years with batteries lasting well over the 2 years warranty in a variety of applications I believe it is valuable to be on a boat and have a charger that in desperate conditions can get your four AA charged in less than your surface interval. Clearly lower charging current are better when you have loads of spares and lots of time however at 500 mAh it takes 5 hours for a set of 2500 mAh if you can afford that then no problems

 

[Tool Belt]

Actually my Sanyo's are not the eneloops. I have the HR-3U 2700 mAh 1.2 volt. Been very satisfied with them.

 

[bvanant]

No worries about disagreeing with me, my boss does is all the time. If you only have 4 batteries and you need to charge during surface intervals then of course you need a fast charger, but batteries are so cheap that I think most of us who dive (at $200 or more per day) can afford to have batteries charging while we are diving. I think my Maha chargers will charge 4 fully depleted (1.1 V or so) to full power in about 2.3 or 2.4 hours but I almost never get them down that low; I change batteries every other dive.
Bill

 

[Interceptor121]

With a microprocessor controlled charger that cools down the batteries the risk of damaging them even with a strong current is fairly limited. I change my batteries either at 300 shots or at the end of the day whatever comes first but I use the same charger for strobe, focus lights, torch x2 so around 8 AAA and 20 AA in use though only one of the torches is always with us. So with a stock of 12 AAA and 32 AA there are at least 8 AAA and 12 AA to charge more if there was a night dive definitely 500 ma charge rate is too slow

 

[Ardy]

Hi guys - I am looking for a new charger and was going to buy Maha C9000? but it only charges 4 batteries and I really need to charge 8. Is anyone using the 8 bay Maha and if so what do you think of it? Any alternatives in reasonably priced 8 bay chargers?

 

[bvanant]

We typically take about 48 AA batteries with us and 5 chargers with 4 bays each so 20 batteries charging and 20 in devices (strobes mostly plus a video camera back). Luckily my lights don't need AA so my needs are lots simpler than yours and almost never have I needed a fast charger (unless someone borrows batteries, which as you know happens).

As for an 8 bay charger, I think 2 4-bay chargers are preferable since if something bad happens (and it will) then you are really out of luck.

Cheers
Bill

---------- Post added April 8th, 2012 at 05:51 PM ----------

Do your batteries get hot at all in that charger? I haven't tested it so it might be good to try it out?
Bill

 

[Ardy]

As for an 8 bay charger, I think 2 4-bay chargers are preferable since if something bad happens (and it will) then you are really out of luck.

Cheers
Bill

Thanks for that Bill I will just bite the bullet and get 2 x 4.

 

[Interceptor121]

Bill
I definitely agree that you are better off with two 4 batteries chargers than 1 8 batteries. However I am at a point where an 8 spaces seems an interesting option with of course also a back up option!

Yes the AAA are a bit of a pain. We have two small fisheye lights, one is a focus light and the other is a saber that I use as macro video light for my compact video, as they are always on (a good idea with those small fisheye that would flood if you play with the screw top) . The batteries are 1100 mAh and they last around 5 hours before dropping significantly so typically I would get to the end of a day diving and recharge anyway.
The AA are instead for the torches (two x 8) and the strobe. After a night dive I would anyway charge both sets. When we don't have night dives I have plenty of spares otherwise I have another 12 for the strobe so in theory the only time I need the speed is after a night dive where I have two sets of 8 plus the strobe and the 8 AAA total 20 AA plus 8 AAA to recharge. I have as a spill over another charger for 4 that gives 1.4 A for AA and 0.7 A for AAA whilst the main one gives 2.2A or 0.55 A. I use the spill over for the AA and the main one for the AAA at the slower current. The spill over has dV only but as the current going in is only(!) 1.4 A the batteries stay cool, the AAA batteries always fresh on the other charger. 5 hours later I will have two set of AAA and two set of AA charged. At this point I am left with 12 AA to charge I put 4 in each charger and I need another 3 hours. Typically this will happen the day after I don't fancy waking up just to swap batteries but that is enough for the strobe.
I have zero room for additional chargers with the current luggage allowance but I think another 4 unit charger looks like an idea

The batteries in the fast charger do get warm despite the dV and dT and fan control if I put them on fast (4.4 A!!!) but I never do that

I have had 2850 mAH for 3 years before the got to a stage of being not usable so I guess this set up works

We typically take about 48 AA batteries with us and 5 chargers with 4 bays each so 20 batteries charging and 20 in devices (strobes mostly plus a video camera back). Luckily my lights don't need AA so my needs are lots simpler than yours and almost never have I needed a fast charger (unless someone borrows batteries, which as you know happens).

As for an 8 bay charger, I think 2 4-bay chargers are preferable since if something bad happens (and it will) then you are really out of luck.

Cheers
Bill

---------- Post added April 8th, 2012 at 05:51 PM ----------

Do your batteries get hot at all in that charger? I haven't tested it so it might be good to try it out?
Bill

 

[muzikbiz22]

I'm just seeing this thread for the first time, so here are my 2 cents. Eneloop, Eneloop, Eneloop. I use in dual Sea n Sea Strobes, and sometimes in my UK torch with the C Size adapter thingy's, (torch becomes buoyant though). Great for travel ! BONUS TIP FOR THE DAY - The AA's that Apple sells with a charger, are rebranded Eneloops. The charger that comes with these is great, small and works with the Eneloops as well. Perfect for dive travel.