Flash batteries?

[Nick Zentena]

I finally got myself a big flash. The problem is it uses 8!! batteries. It's old enough that I doubt the words NimH or maybe even Nicad had crossed the minds of designers. What are the issues in using these types of batteries? The voltage is lower but that shouldn't be an issue. I've heard problems with the batteries providing power quicker then alkaline batteries. How much of an issue is this?

Quantum makes a battery for the flash but the price seems crazy. It's just a 12v lead acid battery and a charger. Is it possible to use a Quantum module with a third party battery? I can buy a 12v battery locally for $10.

FWIW it's an Agfatronic 643. Hopefully it works when it shows up. OTOH the thought of feeding it batteries makes me wonder.

 

[Bighead]

http://www.aljacobs.com/Packmodone.htm

I've thought of being a pioneer and trying one of these packs. The guy, seems, to know a lot about batteries. He is also very pro-digital too... So, who knows ... He sells them with a quantam module too... I posted this here and it seems nobody has used them but I am alful curious about them.

 

[Nick Zentena]

I looked at his stuff yesterday. I don't think any of them are big enough-( His stuff is a lot cheaper then a quantum but still a lot more then a little lead acid battery.

 

[Woolliscroft]

I use two big, but old, Metz guns. I use them with nicads and, occasionally with dry cells, when I can't charge nicads fast enough. I've not noticed much performance difference between the two, except that alkalines last longer.

David.

 

[Donald Qualls]

One thing to watch for before spending money on batteries: it's not uncommon for very old electronic flashes (like one I have, that is about 40 years old and, BTW, has internal NiCd rechargeable battery) to have a bad flash capacitor. These are large electrolytics and seem to have a shelf life issue; they simply dry out after 30-40 years and won't take a charge (and if the capacitor won't hold 400 volts with a suitable number of coulombs stored, the flash will be weak or won't work at all). And it can be hazardous to replace these capacitors; even if they're too weak to fire the flash, they can still deliver a jolt that's capable of killing you.

That said, if the original power source is 8 carbon-zinc or alkaline batteries, you can probably cobble up a temporary supply from your car's lighter socket to test the flash circuitry before buying an external battery. Be careful out there -- even a lighter socket can bite!

 

[Nick Zentena]

I'm just hoping Nicads will work without damaging the flash. The cost for something like the Quantum is way out there. The cheapest price I've found is 3x what I paid for the flash. Considering it's just a 12v lead battery I can't see myself spending the money. I'm not sure when Agfa quit making flashes but it's been awhile. OTOH I've got two smaller Agfas. Similar vintage and they're fine. Likely the best value in midsized flashes. I bought each one for less then the cable attached to them would sell for on it's own.

I actually built a portable car lighter socket-) It's just a socket and some wire with quick connects. I can attach it to a small 12v battery and use it for anything that plugs into a lighter socket.

 

[MattKing]

Careful with Nicads

The other problem with Nicads is that they have a lower internal resistance, so in some cases the resulting current is too high. Even if that doesn't initially damage the flash, it can result in heat build-up, which can either cause damage, or result in burns.

 

[Donald Qualls]

The consideration with current from NiCd cells is valid with some equipment, but probably not with an electronic flash, especially not one that has an external power connector that likely would have used an gel-cell if it's new enough they'd been invented (and they go back into the 1950s). The other consideration, however, is that you may need 10 NiCd cells to replace 8 carbon-zinc or alkaline cells; the lower voltage might translate into not having enough peak to top off the capacitor, or getting very few flashes from a charge. The other thing to consider is that this type of device is capable of deeply discharging a battery, and doing so with a multi-cell NiCd risks reverse charging a cell, which is generally Very Bad. These cells shouldn't ever be discharged below 1.0 V per cell, if they're to maintain a good lifetime. That kind of deep discharge is bad for any lead-acid battery, too; it might be worth seeing that kind of life you get from the 8 alkalines. You can buy Duracells pretty cheaply at Costco...

 

[Nick Zentena]

Hopefully it turns out to use AA then I'll get get rechargeable alkalines. I thought it used bigger batteries but all the sites on the web claim AA.

 

[Brac]

The other problem with very old flash guns is that the voltage can be incompatible with modern electronic cameras and can damage the circuits. For example I have an early Metz CT-1 which I can't safely use with recent Pentax autofocus 35mm SLR's.

 

[Roger Krueger]

The only issue with NiCd (not really with NiMH) is that the extra current capacity can recharge the flash faster, which, under constant fire-as-soon-as-the-ready-light-comes-on abuse could overheat the flash.

Recharagble alkalines truly suck. I thought they'd be cool and got a couple sets and in fewer than 20 cycles they were down to half capacity.

Check the sync voltage if you're using an electronic camera. Most pro bodies are fine with high voltage (1-series Canons, etc.) but consumer TTL cameras--Rebels and N70s especially--really do go pffft.

 

[Nick Zentena]

The flash takes Metz 300/3000 cables so the sync voltage shouldn't be a problem.

So Nimhs are okay?

I've had good luck with the alkalines. They are lousy choices for a wedding photographer but if you don't need to run them down then they work fine. I just top up the charge after a couple of rolls.

 

[Donald Qualls]

NiMH require considerably smarter chargers -- they'll be damaged by levels of overcharge that would barely detect as fully charged with NiCd peak chargers. If you have a charger made specifically for NiMH, and cells designed for rapid discharge, they'll do better than NiCd for anything except absolute maximum discharge or charge rate (and no electronic flash comes near that current draw -- 10 NiCd D cells with welded connectors can start your car).

 

[Nick Zentena]

I picked up a Nimh charger awhile back. Then found out it was cheaper to buy 24 batteries off Ebay then four locally. If Nimhs are okay I can use those. So it won't damage the flash then?

 

[Donald Qualls]

I've used NiCd cells in a AA powered consumer flash without problems. Aforementioned overheating problems are the only concern, and should be an issue only if you operate as fast as the flash can recharge for an extended period. Worth noting, if the flash has an external 120 V power capability, it's probably rated to operate at 4-5 times the flash-per-minute rate you can get with the very best rechargeable cells.

 

[Nick Zentena]

I won't be using many full power flashes. One of the reasons for getting the bigger flash was more partial power flashes. If I'm explaining that right.

 

[Donald Qualls]

Full power or partial, the concern would be prolonged operation as rapidly as the flash can charge the capacitor -- equivalent to maximum battery drain. If you let the flash sit as long after it's fully charged as it took to charge, it shouldn't even become a problem.

 

[Roger Krueger]

Worth noting, if the flash has an external 120 V power capability, it's probably rated to operate at 4-5 times the flash-per-minute rate you can get with the very best rechargeable cells.

Not necessarily. The thing that generally fries in an overheated battery flash is the chopper transistor, which cuts the incoming DC into pulses so it can be stepped up by a transformer to 400+ volts. This would not be part of the circuit under external AC operation, nor under high-voltage-pack operation.

(Yes, I've had a few fires. I like hooking 283s up to 6v 4ah lead cells, which will recycle the flash a lot faster than the best AAs, definitely fast enough to cause trouble. Worse, in early 283s the chopper fails closed, not open. Cooks the traces right off the circuit board!)

 

[Donald Qualls]

Worse, in early 283s the chopper fails closed, not open. Cooks the traces right off the circuit board!

Well, at least this will bring proceedings to a halt so you have half a chance to disconnect and set aside the smoking unit and plug in a spare... :rolleyes:

 

[Nick Zentena]

After all that stress and worry. The flash shows up and the manual tells me. To use either alkaline or Nicad. At least I think that's what they mean. It's clear the manual was translated from something else. Likely German. I'm guessing Nihm will be okay to. OTOH the thing seems to charge slowly with alkalines.