Paul C. Buff, Inc. Technical Forum

In the VML specs it says life is estimated at 200-300 recharges or 2-3 years.

I'm just wondering which is more important (years vs. charges) or if they both matter.

i.e. Is the battery going to start losing life at around 3 years even if it hasn't seen much use? Or does it really depend on the number of full charges?

Or what if I use it 300 times in 1 year? Will that deplete it or is it more dependant on the age?

Thanks,
Chris

Lithium batteries are fairly new science and there is little really definitive info around. The best source I have is Battery University.com and info I receive form the manufacturer. Even our battery supplier can only give us educated guesses.

As for your questions, if you used the VML every day, and completely discharged it and completely charged it every day, indeed it would probably be depleted in about one year.

But this would not be normal, likely usage, because of the very high capacity (130 Wh) of VML batteries, compared to around 40 Wh for Profoto B1, Elinchrom Quadra Ranger Hybrid Lithium and similar.

In a typical VML session, chances are you will only use perhaps 1/4 to 1/2 the capacity available during a session. In such use, if you fully charge the VML after each use, the battery will likely last 2-4 years.

Another factor is the Watt Hours drawn from the battery compared to it's Wh capacity. A large capacity Lithium battery operating at a relatively low Wh load can last from 500 to 800 charge recharge cycles, While a low capacity battery driving a high current load (i.e. Profoto B1 or Elinchrom Ranger Quadra) might last for only around 125 to 150 charge cycles.

Systems using the latest LiFePO4 Lithium batteries, such as our new VLX™ can last from 1200 to 1500 charge cycles, with a storage life of over 10 years. Thus, while the VLX battery costs significantly more than the VLM battery, it costs a fraction of replacement VLM or other NMC batteries in long-term usage.

So based on what you are saying it sounds like the important part is the number of charging cycles not the age of the battery. Is that correct?

If the battery sits pretty much unused at 70 percent charge for most of its life will it retain a decent capacity for longer than 3 years? Or is 3 years and upper limit of the battery's life?

Both will play a role. 3 years is probably the upper age limit of the batteries (YMMV). Also, remember a end of life battery can still hold a charge and deliver some amount of power. It will not necessarily be an issue of zero power when the end of life (as defined in the context of batteries) is reached.

Both will play a role. 3 years is probably the upper age limit of the batteries (YMMV). Also, remember a end of life battery can still hold a charge and deliver some amount of power. It will not necessarily be an issue of zero power when the end of life (as defined in the context of batteries) is reached.