Sunpak 544 battery pack

This flash uses 6 AA batteries so that means 6 @ 1.5v is a 9v system. If you use rechargeable 6 @ 1.2v it is only 7.2v. I have been looking at trying to make an external battery pack and seen RC car/plane batteries come in 7.2v, 8.4v, and 9.6v bundles. Does any one know if I used the 9.6v pack would it hurt the unit. I have also looked into using SLA battery but they dont make 9v type and only option would be to use a 8v battery but the charger for that is special and that alone is over $50. I have 2 of these units so I want something that will be cost effective for both. So if anyone is also a RC buff would those type of batteries do well enough to fire flashes for hundreds of shots at sports events?

no one has any help?

You will not find a 9 Volt SLA. Lead acid cells produce about 2 Volts, so there is no way to stack 2 Volt cells to make a 9 Volt battery of cells. 4 cells would net an 8 Volt battery of cells., and 5 cells would net a 10 Volt battery of cells.

Sometimes discrete devices fall short or step over the desired target.

If your 544 will work nicely with 6 NiMH AA cells inside (1.2 X 6 = 7.2 Volts), then an 8 Volt SLA should also work nicely. But a 8 Volts SLA battery is not one of the more popular configurations.

Enjoy! Lon

FlashZebra wrote in post #6557922
But a 8 Volts SLA battery is not one of the more popular configurations.

That is part of the problem Lon. I have wondered if the SLA option would be better than the NiMh packs I have found. The way I understand the SLA is more like a Jogger and can go same speed for long times and NiMh are more like sprinters they go fast but die quicker and last not as long. The SLA option is the 8v 3.2Ah powersonic PS-832 ($24) combined with pscbw-8250a 8v charger ($50)

I did find a NiMh pack that is 5000mAh (is that not 5Ah) with a charger.
https://www.batteryspa​ce.com …ction=VIEWPROD&​ProdID=385
That it just a little more that the charger alone ($55)

Your initial premise is also wrong. Its not the Voltage that gives you the faster recycle times, its the current deliver speed that gives you a faster recharge time.

I tested this with 4 NiHM 2700mHA vs. Energizers in a 420EX. The Alkalines weren't even close. With 50 shots at 1/4 power (continuous) the NiHMs did it 35% faster than the alkies.

aram535 wrote in post #6562883
NiHMs did it 35% faster than the alkies.

I really dont care if it does it faster. I want it to do is steady for over the duration of the multiple games I would need them for. I understand that the rating (ie Ah or mAh) is important but having the proper voltage output is also important as the 544 is a 9v system you cant use a 12 volt battery hoping to get better recycle. I also know that the higher the given rating is it will also increase performance.

For those that use this flash system.... What do you use presently for power this unit?

Sure you can, that's what a battery pack does. You can pounce on the flash at full power and shoot off 10 in a row ... you'll burn out your flash from heat not from the extra power. It has a buffer in there, the faster you can recycle that power the faster you can shoot. In sports, that's more important as I can replace batteries easily and I can recharge another set faster than I can deplete this set. I usually don't go above a 1/4 power and I spread the load across multiple units. (i.e. If I need 1/2 power, 2 flashes at 1/4 power give you the same short distance output.) But I can shoot twice as fast.

I have two battery holders for my 555. When I'm using that flash I just make sure the spare holder is full of fresh batteries. It doesn't seem to burn them too fast.

aram535 wrote in post #6569048
Sure you can, that's what a battery pack does. You can pounce on the flash at full power and shoot off 10 in a row ... you'll burn out your flash from heat not from the extra power. It has a buffer in there, the faster you can recycle that power the faster you can shoot. In sports, that's more important as I can replace batteries easily and I can recharge another set faster than I can deplete this set. I usually don't go above a 1/4 power and I spread the load across multiple units. (i.e. If I need 1/2 power, 2 flashes at 1/4 power give you the same short distance output.) But I can shoot twice as fast.

Are you trying to say i can use a 9.6 volt and it would not hurt it? What if i used 12 volt..........?

It isn't good for the flash I'm sure but it can handle it.

I have never tried very high voltage, but I know that you can pump more than 4 AA batteries worth of voltage through the flash without a problem. That's how the large outside battery packs work. You can get full power every 1/2 second with those.

If you go to the store and by a 9v alkaline square battery and test it with a volt metre, it will read about 9.6v when it full and it will drop to about 8.6v before its officially dead. Same with an aa at 1.5v it will read from 1.65 full to 1.4 empty.

Alkalines start over there rating, and drop off as they waste. Ni-cad Ni-MH, put out consistent voltage pretty much from full till empty. So anything that says it takes alkaline batteries will be fine with a few percentage above spec. If the weren't then duracell and energiser would have been in a lot of trouble by now.

So your rechargables in series wiring are putting out close to what an near empty set of alakalines would in terms of voltage, but they are consistant until they die. The alaklines start great and get worse (recycle time gets longer) This is also why a lot of devices when presented with rechargable batteries indicate half or low power because they measure voltage on the assumption that it will fall as the batteries waste (not true for the rechargable variety, well true to a much lesser degree that they can't measure)

If it was mine I'd happily take the 9.6v, but as its your flash and I don't want to bust it on you, I'll say go with the 8.4v, your flash will see that as a slightly used battery. That battery is likely to have a slightly higher output in terms of mAmp/hour (how long it will last) and if you don't want to change batteries thats all important

I have taken appart a rechargable 8.4v from an airsoft gun and it was pretty much 7x 1.2v AA rechargable cells in series stuck together in another package. It was in a 3 down, 3 up, with a squashed 1 joining the 2 sides. I was going to use some of the 9v alkaline variety to replace this but they turn out to be around 1100 mAh output so they would last half as long as 6x1.5v AAs at 2200 mAh. The I was going to use 2x9v in parrell wiring so still 9v but now with double capacity of 2200 mAh, but then I lost interest in the whole thing.

So in summary an RC 8.4 should be fine, and a 9.6 should also be fine, but likely no extra benefit and it will drain faster. But nobody knows for certain how your flash was built so if it or you get blown up its your own fault.

To NVcameraman:

I know this thread is a year old, but I figured I'd chime in...

Have you ever tried the Sunpak TR-Pak II or IIa? I have a few and they're great - pretty inexpensive and super fast. They use a 7.2V Ni-Cd battery cluster (6 'C' cells) that charges in the battery pack housing with the appropriate charger (QBC-5 or CHG-20). They've been discontinued and replaced with the TR-2000, which has the same performance but uses interchangeable cords (for different flash brands, like Quantum does) and a removable Ni-Cd battery.

If you're using Sunpak flashes (544, 555, 120J, etc.), the TR-Pak II(a) is a way better buy. You can still get replacement cells from B&H (CL-Pak IIa used in the TR-Pak IIa or loose 'C' cells for the TR-Pak II).

I'm in the process of rebuilding my battery packs and replacing the crummy Ni-Cd 'C' clusters with 4500 mAh Ni-MH 'Sub-C' clusters (also 7.2V). You get more capacity, marginally faster recylcing and no memory issues when charging compared to the old Ni-Cd technology. Basically, you can sustain a great discontinued product indefinitely by buying replacement cell packs from hobby stores or custom battery stores. Not only are the Ni-MH clusters better in every way, but they're also cheaper than the Sunpak-branded replacement cell cluster.

The only downside of the TR-Pak II(a) is that the flash connector is hard-wired, so you can only use it with Sunpak flashes. One of these days I'm gonna do surgery on mine and see if I can adapt it to a current Nikon flash.

I actually built some battery packs last year for this flash and made up wooden dummies to place in flash head to send power to them. If you want to see set up I can try and take a few pictures of the set up.

Alright, let's see it - I'm curious.

Here is what the pack looks like