You got it. The Profoto unit is rated much higher than the lithium replacement. The manufacturer said they would need to redesign the unit for it to work in this application. We'll probably never see it. It's been said that the Tenergy version is rated higher and does work in the AcuteB. Only one place appears to sell them and they aren't in stock. I guess time is the only answer at this point, unfortunately.
I can confirm that this Tenergy cell (which is finally in stock somewhere) does work in the AcuteB albeit with a non functioning battery meter. From what I've heard these things are pretty hard to kill on a normal shoot that isn't done at full power. It's a small price to pay but my back thanks me.
I can also confirm that this K2 Energy cell also works in the B2/7B packs but has the same battery indicator issue. My back really thanks me for this one.
Thanks for the followup, Chad. I just confirmed my SLA is fully dead, so must decide on a replacement for my (original) AcuteB. Do you have details on the procedure to extract the cell from the Profoto cartridge frame? I have tools, meters, and a hardware guy nearby.
All that you need to get the job done is a T10 torx bit for the four screws on top of the pack. The cell then slides out of the casing. The connectors are just quick connects and slide right off of the terminals. It doesn't get an simpler, really. It's a 3min job.
Thanks for the info on using the Tenergy cell to replace the old AcuteB batteries. Keep us updated on any new findings. My back (well mainly my assistant's back) thanks you!
I disassembled the AcuteB battery cartridge - a trivial matter. Talk about a profit center for Profoto! The Tenergy LiFePO4 battery is $65 versus $600. Rather hard to believe the cartridge frame can account for the difference. I decided to recell with another SLA since I like the state-of-charge lights more than lower weight. Plus, I'm not completely convinced the chemistry for floating charge is compatible. SLA maker Power-Sonic has an awesome array of technical docs and full specs for their product line, so I'm going that route via Amazon. The pertinent models are PS-1250 (F2 connector tabs) and PSH-1255. Like the Tenergy LiFePO4, these can deliver the current that the AcuteB needs for rated performance (about 18A). The PSH-1255 has higher peak current, more capacity, higher price, and is 0.5lb heavier. Will upgrade in a week or two.
rico wrote:
I disassembled the AcuteB battery cartridge - a trivial matter. Talk about a profit center for Profoto! The Tenergy LiFePO4 battery is $65 versus $600. Rather hard to believe the cartridge frame can account for the difference. I decided to recell with another SLA since I like the state-of-charge lights more than lower weight. Plus, I'm not completely convinced the chemistry for floating charge is compatible. SLA maker Power-Sonic has an awesome array of technical docs and full specs for their product line, so I'm going that route via Amazon. The pertinent models are PS-1250 (F2 connector tabs) and PSH-1255. Like the Tenergy LiFePO4, these can deliver the current that the AcuteB needs for rated performance (about 18A). The PSH-1255 has higher peak current, more capacity, higher price, and is 0.5lb heavier. Will upgrade in a week or two.
I hope these Power-Sonic works for you. I had Calumet Photo replace my SLA with a "compatible" replacement battery. After a few uses, the life of the battery seem to be dying. It wouldn't fully charge anymore. I don't know the brand as I haven't open up the battery cartridge yet. I plan on trying Chad's suggestion for Tenergy and see how that goes.
Let us know how the Power-Sonic works out in case I go back to SLA batteries.
Lead-acid batteries (even SLA) have limited shelf life after which irreversible sulfation occurs, and capacity is rapidly reduced: probably why Profoto has a sale on battery packs every year. Power-Sonic graphs are quite demonstrative of the time frames, which vary with cell design and storage temperature. Date of manufacture should be stamped on any respectable SLA product, but that's not easy to inspect in most purchasing scenarios.
pjny,
I don't believe the bare cartridge frame is offered for sale. On ebay, you might find a complete cartridge with exhausted battery for a low price. Then get it recelled professionally, or do it yourself. The PS-1250 (F2) mentioned earlier is just $24 from respectable sources: not much risk if you're handy with a screwdriver and a multimeter. Chances of smoking your pack is quite small.
I'm going on vacation, so this small project is on hold.
As far as the SLA replacements go, the proven Profoto cell goes for $30-$40 direct from the MAC group. I've gone that route in the past with no issues. I don't see the reason for trying to find a third party SLA replacement just to save $5-$10 on something that in the long run may not be a wise decision. Just my 2 cents.
chaddoyon wrote:
As far as the SLA replacements go, the proven Profoto cell goes for $30-$40 direct from the MAC group. I've gone that route in the past with no issues. I don't see the reason for trying to find a third party SLA replacement just to save $5-$10 on something that in the long run may not be a wise decision. Just my 2 cents.
-Chad
Chad,
MAC Groups sells the Profoto battery direct? In the past, they say I need to send the whole battery in so they can re-cell, even though it it a simple swap. It was only $65, so it wasn't a deal breaker.
I went into my email archive and found the email conversion. The battery was actually $45. I was told that they (MAC Group) had tested over 12 batteries and the others didn't compare to the units custom made for Profoto.
I'm back from vacation, and will receive my replacement SLA this week: Power-Sonic PSH-1255FR from an Amazon seller. This is the high current, high capacity version. Price: $22 shipped. I also didn't know MAC offered bare AcuteB batteries for sale, but it wouldn't change my plan. The Profoto version may be properly spec'ed, but no way is it magical. This battery technology is mature.
I got 2 LiFePO4 from Tenergy and they are very light. With limited testing, I fired off a couple hundred shots at medium power. So far so good. As Chad said, only drawback is no battery meter. I may never go back to SLA's.
I got 1 of the Power-Sonic SLA, and they are very heavy. Fit into the cartridge frame is perfect. Battery meter is working (amber) in initial state. No question that LiFe is attractive and, going forward, I hope Profoto engineers a working meter. More than money, recelling yourself is simply less hassle than packing and shipping the dead battery (not to snub the money saved).
Thanks to Chad for jump-starting these activities.
Update: Freshly charged, this battery drove the modelling light for 49min. Profoto claims 50min and their battery is lighter by ½ lb. Power-Sonic says max capacity is reached after several weeks on trickle charger, but price/performance now is already very decent.
I received your message but I'll reply here. I'm not so sure that the battery you have linked to will work in your pack. That one maxes out at 30A while the one that I linked to above maxes out at 50A. I have to think that yours will trip out rather than work properly.
Update for the Power-Sonic SLA, mentioned above: the voltage at full capacity is slightly lower than the Profoto OEM, and has two side-effects. First, the battery is quicker to show lowering capacity with use, meaning the pack shows the red LED sooner. This is not a big issue. Second, and more serious, is that charge termination is not properly sensed by the Profoto changer, and battery overheats. I avoid the situtation by charging the battery outside the pack which is enough to remove some resistance from the circuit. If I stick with SLA, I will place further orders for the the OEM version from B&H (available at a decent price).
Hope you'll have the time for an answer, thank you
All the best from Denmark
Bo Egestroem
Can you confirm if you have done any of this yet? I am purchasing a 7B 1200 pack with 2 batteries. I want to replace them with LIFE batteries. Any help would be great. Anyone have a walkthrough of sorts for this. The $1100 price tag on BHphoto is crazy. Thanks!
