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Hi all, I understand that some of you use the above batteries. I have a few sets and the don't seem to hold their charge long after a recharge.

I'll have them charged up and go to use them in the SB-800 a couple of weeks later and they can't power up the flash.

I was just wondering if this is normal. It's happening with a number of sets of the Engergizer batteries. Is it my charger maybe? I'm using an Inca multi-voltage charger for NiHM/NiCD batteries.

Baboo, a friend of mine had a similar sounding problem. His charger was showing that it was charging and that the batteries had finished charging etc, but after 40 or 50 firings of the SB800, they were flat.

He tried a different charger and they are now behaving perfectly, hundreds of firings on a set of batteries. See if you can borrow someone else's charger for a test. That would be my first guess.

Cheers
John

Rechargables do also tend to lose their charge fairly rapidly as well when stored.

I had the same problem initially but (weirdly) after a few (say more than 5 after use) charges they now last me very well....

Hmmm... Might just give the batteries another charge and then run them through the SB-800 and see what happens.

If that doesn't work, maybe it's a bunch of dodgy batteries.

One of the 5 sets that I have seems to hold it's charge very well though compared to the rest.

I had these batterys for a couple of weeks, couldnt hold the power then they started leaking and forming a blue crust over the ends... so i hoisted them....

Tim

NiMH batteries do not seem to hold charge for very long ...
i have 4 X4 sets and after a couple of weeks they have lost most of their charge.
all three brands i have do the same from new.

from best to worse i have ...
8 powerbase 2500 mAh
4 inca 2600 mAh
4 energiser2500 mAh

Charge them up and leave for a day then check the voltage of the individual batteries as one may be faulty which drags the voltage down of the other ones.

I have one dud energiser

I've got 2x 2200 Kodak ones and 4x 2500 Energizers, all of them work fine, and I'm using this very old and slow charger, I think maybe it is your charger... Or the new batteries aren't quite up to standards... I had my energizers for about a year now.

baboo,

I have about 8 of them and no issue so far. Yes they lose charge in storage. I also tend to run the discharge cycle after about 5 chargings.

hth

cheers

After charging, I usually pop my NiMh batteries into the door of my fridge until I need them... They hold their charge for a lot longer that way...

I have the same problem with mine. I have 15 of the buggers, which initially held their charge very well, but now they don't last very long at all. I'll give another charger a go and see what the outcome is.

cheers

You're right, NiMH's don't hold their charge very well. In that respect they're even worse than NiCd's. It's also very important to charge them properly, i.e. with a microprocessor controlled, thermistor equipped pulse charger. Any charger that only accepts batteries in pairs is out.

The cheapest chargers I've found that appear to do a good job on NiMH's are the Energizer badged one they sell at DSE and other places (~ $80) and the Jaycar one (~ $100).

I've ruined many sets of NiMH's (< 50 charge cycles before becoming useless) with cheap dodgy chargers.

I always carry a few sets of alkalines and/or AA lithiums as backup, because I can never be quite sure about the state of the rechargeables...

Cheers
Steffen.

alkalines are no good in a Pentax as you only get 30 pics out of them ... lithiums can get up to 1500 and also hold their charge so are the best bet for back up.

the MAHA brand batteries and chargers have given me excellent serive. The NiMH batteries tend to loose approx 1%-2% charge per day so easy to calculate how much charge you have left after say 2 weeks. (15%-30% loss)

Mine are can't even fire up the flash after less than a week.

Welcome to the wonderful world of NiMH!

• Alkaline - low capacity for high-current device (e.g. cameras/flashes).
  Keeps its power on the shelf for a long time.
• NiMH - high capacity for high-current devices.
  Rechargeable, but loses at least 1% of its charge per day.
• NiCd - reasonable capacity for cameras/chargers (better than NiMH for things like motors though).
  Rechargeable. Overcharging more-likely to damage cells than NiMH: resulting in "memory effect" of reduce capacity.
• Lithium - high capacity for high-current devices.
  Keeps its power on the shelf for a long time.
  Expensive, non-rechargeable.
• Lithium-Ion - high capacity for high-current devices.
  Rechargeable, but needs special chargers to avoid pyrotechnics.
  Not available in AA.

NiMH batteries are wonderful things (I use them for flashes and radios) but you need to understand that they need regular topping up!

I agree with all of the above except the Nicad "memory effect" which was never proven to exist.
The effect of different cell capacities in battery packs can result in unequal discharge, recharge peak voltage trips which can increase over time.
Single cell "memory effect" has been unable to be replicated in NASA's laboratories. This is where the "phenomenon" was first put forward to deal with the lack of power during repeated dark/light cycles with early satellites.
Having been involved with aeromodelling for almost 15 years, I have had intimate experience with the technology development of nicads. I remember when a 600mAh AA battery was 25 dollars a cell and was the ultimate fly all day accessory.
As battery life is your insurance, modellers adopted the latest battery charging technology as they came out. If you want damn good and cheap battery chargers, go to your local model shop.

Not one of the modellers I know who had battery discharge/charge records EVER managed to find "memory effect". They noted reducing charge/discharge capacity as the cells aged then they died. They noted single cells dying faster than others.
No memory effect.
Ever.

So lets kill this myth.

Or use Nickel Metal Hydrides...

Baboo, I commented that I thought it could be your charger earlier in this post. I just changed to my second set of Energizer 2500s while I was out with the SB800 today. They had been charged about 4 weeks ago and have been in my backpack since. I got about 20 flashes out of them before they were flat. I'd have to agree now that it's not the charger, it's the 1%-2% loss per day.

Cheers
John

Well as I've said, I've had my 2500mAH engergizers for about a year now and it's working like it was new, I've had my Kodak 2200mAH ones for more than 2 years and it's working fine as well...

I'm not sure there is such a big inconsistency in the quality of the batteries...  BTW, I think Ted's (camera shop) in Brisbane city are selling 4x 2600mAH recharagables for $12, might be worthwhile to check it out for Brisbane people.

I've noticed one of my Engergizer 2500 has changed colour in the carboard bit on the positive terminal. Only one out of the 14 I have, but I'm keeping a close eye on it as I don't trust it.

I'll have them charged up and go to use them in the SB-800 a couple of weeks later and they can't power up the flash.

That is normal, always fully charge the cells before use.

shutterbug

just to clarify for us non-IT literate / electrical dudheads.

It is OK to charge a compatible set of ni MH prior to heading out for a days shooting even if they may have only lost 10 - 20% charge from a charge a week before.

Recharging (before completely 'dead') wont reduce the capacity of the battery to fully recharge.

It IS safe to keep them in the fridge enclsed in a cair tight container?

I have two sets of 8 - INCA brand and charger for my SB 800. Hope they are worth the $$$$ I paid !

thanks for clarification on this

cheers

R2

rookie2 wrote:It is OK to charge a compatible set of ni MH prior to heading out for a days shooting even if they may have only lost 10 - 20% charge from a charge a week before.

Recharging (before completely 'dead') wont reduce the capacity of the battery to fully recharge.

Correct (as long as you have a decent charger which charges each battery individually, and won't overcharge the batteries).

It IS safe to keep them in the fridge enclsed in a cair tight container?

I don't see why not. Of course you'd better let them warm up to room temperature before opening the container when you want to use them (otherwise the condensation could/would be a problem).

I have two sets of 8 - INCA brand and charger for my SB 800. Hope they are worth the $$$$ I paid !

I'm guessing that if they're Inca-branded then you didn't pay much at all, and that yes they'll be worth exactly what you paid for them!
Of course you may be lucky and have them work well for you (my Inca charger is working fine, but the only Inca cells I've had have been crap). Inca just rebadge generic items from o/s in the Australian market, I don't think they do any development of their own.

I recall once hearing that if you fast charge NiMH as opposed to trickle charge it reduces their life. Can anyone confirm/deny this?

I always keep a set in my flash, and they never die - current set in there for a month plus! Just in case I always keep a fresher set in the bag.

EDIT - and they are niMH

I got two sets of 5 "Prolink" NiMH ones and they are fantastic. I don't remember a time when I ran out of batteries in the middle of a shoot.

They were damn cheap too and the charge that came with them was damn fast.
Alex

This http://www.batteryuniversity.com/ is a handy link for information on rechargeable cells.

Cheers

myarhidia wrote:I recall once hearing that if you fast charge NiMH as opposed to trickle charge it reduces their life. Can anyone confirm/deny this?

There is plenty of info out there on charging NiMH. One such source is http://powerstream.com Have a look at their tech pages on charging.

Fast charging is okay but... there are criteria to be met to protect the cell.

Cheers