[fevbusch]

I'm having some difficulty trying to find out about the battery life of the rechargeable lihium -ion Battery D-LI109.
With my old rechargables (AA's) If they were recharged before they were depleted the batteries would lose their
ability to recharge fully, because the battery memory became diminished in some way.
Is it safe to recharge the D-LI109 before its time.
My plan is to use the wonderful Energizer AA Ultimate Lithium (non re-chargeabe) batteries, from which I seem to get about
somewhere in the area of 1,000 shots (hang the cost, its worth it). When they deplete I will then use my D-LI109 until it
is about to run out (I"ll store it in my camera bag as a backup). When it gets to about 400 shots I will then put a fresh
set of the Ultimate Lithiums in the K30, recharge the LI109 and keep it in my camera bag as a backup.
I will appreciate any input regarding this question. Warmest regards , Freddy

[Na Horuk]

I think the manual mentions the battery is "no-memory" rechargeable. So you can charge it whenever and it will not get lazy.

[SteveB]

Li-ions like to be charged before they're flat and not taken to a completely full charge if you want to get the maximum no. of years out of them. I wouldn't worry about it though. They lose capacity at about 3-4yrs whatever you do.

Modern AA low self discharge batteries are very good also, no memory effects and can last years longer than Li-ions assuming a good charger.

[JimJohnson]

Yes. +1 on SteveB's response. The "memory effect" is from an earlier battery chemistry - Nickle Cadmium (NiCd). Lithium Ion (LiON) batteries like frequent partial recharges, but tend to self-discharge when in storage down to 80% to 50%. So, sitting in your bag long term between replacement of your Engergizer Lithium batteries (no direct connection to the rechargeable LiON batteries other than also using Lithium), without a periodic topping off isn't the best plan.

The AA low self-discharge batteries (Sanyo eneloop is the prime example) have two important attributes. First, they lose very little charge in storage, for upwards of two years. Second, like LiON they can discharge a lot of current in a hurry. This is important. Our dSLRs like to suck big amounts of current during an exposure - although their current demands are far smaller outside an exposure. This is where your run of the mill AA rechargeables and especially non-rechargable AA alkaline batteries have problems.

ALL current battery chemistries have a limited life-span. Even with good care, it is rare you will get more than the 3-4 years use as SteveB noted. And in my experience, only 1-2 years use is not outside the norm when used heavily with deep discharge practices.

[SteveB]

Yes. +1 on SteveB's response. The "memory effect" is from an earlier battery chemistry - Nickle Cadmium (NiCd). Lithium Ion (LiON) batteries like frequent partial recharges, but tend to self-discharge when in storage down to 80% to 50%. So, sitting in your bag long term between replacement of your Engergizer Lithium batteries (no direct connection to the rechargeable LiON batteries other than also using Lithium), without a periodic topping off isn't the best plan.

The AA low self-discharge batteries (Sanyo eneloop is the prime example) have two important attributes. First, they lose very little charge in storage, for upwards of two years. Second, like LiON they can discharge a lot of current in a hurry. This is important. Our dSLRs like to suck big amounts of current during an exposure - although their current demands are far smaller outside an exposure. This is where your run of the mill AA rechargeables and especially non-rechargable AA alkaline batteries have problems.

ALL current battery chemistries have a limited life-span. Even with good care, it is rare you will get more than the 3-4 years use as SteveB noted. And in my experience, only 1-2 years use is not outside the norm when used heavily with deep discharge practices.

I've got AA Uniross Hybrios from 2006 that still deliver like new. Rumour at the time was that they were made by Sanyo.

[fevbusch]

Hey guys, thanks for your helpful replies.
I have another question!!! I just came back from a trip to Philadelphia Historic spots with K30 + 16-45 lens + the fully charged Pentax Lithium L-ion battery.
All shots outdoors with no flash used.
When I got up to about 420 shots, my focus became a bit erratic in that the shots wouldn't click. I kept trying and still had a little sporadic failures.
Could this mean my Lithium battery was getting low?. It didn't show up as low on the screen. Always read full. Freddy