Charging your camera battery

[Heika Werner]

What is your camera battery charging procedure? When the light indicates that the battery is fully charged, do you leave it on the charger longer? Does doing so squeeze more juice into the battery? Or do you pull the battery right out?

Also, is "refreshing" batteries still required?

[Shortie]

When I charge my batteries I do the following

Charge them up until the light becomes solid and then leave them on charge for another 15 mins - I remember reading somewhere that when the light changes to solid they are 90% full

Do not leave them on charge continuously as they can degrade over time due to heat - but it takes a while and I know I can get two Canon Batteries for about £10.00 so does it really matter as long as you have spares for the all important shoot

As for conditioning / refreshing I have no definitive proof but I believe that the NiMH type don't need to be refreshed - I have never refreshed mine except when they have completely run down - someone else here may be able to help

Shortie

[Blinky]

I have Nikons and while used to think I knew what I was talking about, I'm now convinced I don't. I've learned some things though.

Originally Posted by Shortie

When I charge my batteries I do the following

Charge them up until the light becomes solid and then leave them on charge for another 15 mins - I remember reading somewhere that when the light changes to solid they are 90% full
Do not leave them on charge continuously as they can degrade over time due to heat - but it takes a while and I know I can get two Canon Batteries for about £10.00 so does it really matter as long as you have spares for the all important shoot

With the Nikon MH-16 charger, supposedly the battery is 100% charged when the end light comes on. The MH-16 instructions state that 'when the battery is finish charging, disconnect it from the charger'... they don't specify if the battery would be damaged if you leave it connected. One would hope that with the amount of money these things cost, Nikon has incorporated a circuit to turn off the charging circuit when it detects a fully charged battery. Nikon's instructions do state that charging a fully charged battery 'may result in damage'. I know that a battery will slowly discharge if you leave it on or off the charger for a few days after it's re-charged.
With a Metz dryfit charger, the green light comes on and starts flashing at about 80% and goes solid (from flashing) at 100%. It has no circuit to turn off the charger and you have to watch and disconnect it when the battery is charged or it will degrade from heat.

Originally Posted by Shortie

As for conditioning / refreshing I have no definitive proof but I believe that the NiMH type don't need to be refreshed - I have never refreshed mine except when they have completely run down - someone else here may be able to help

Shortie

It may be that my charger is defective but everytime I've used the refresh function, my batteries stopped holding a decent charge... some of them permanently, others I was able to resurrect by fully discharging them several times before charging them. I have both Nikon OEM and Japanese knockoffs. all are NiMH.

I don't understand why this has to remain such a mystery. Manufactureres have surely tested their power systems and sources. Why can't they just furnish the complete information and be specific about charging and discharging procedures. Nikon's MH-16 instructions are pathetically vague about everything except what kind of replacement batteries to buy 'Only Nikon OEM'.

Maybe somebody like Scoundrel can shed some light on this stuff.

Good luck.
Chip

[scoundrel1728]

Originally Posted by B

Maybe somebody like Scoundrel can shed some light on this stuff.

About the best I can do is to say it depends on the charger. The newer, better rapid chargers have a special IC in them that pulses the charge of NiMH and Li-ion batteries in a special way so they can be charged at full speed, or nearly so, until the charging cycle is complete.

I haven't run into the term "refresh" in this context before, but in the Ni-Cd days, it was recommended that batteries be "conditioned," i.e., completely discharged, before charging them. NiMH batteries that come as separate cells can often have their capacity restored by conditioning the separate cells before recharging the battery as a whole. This won't work with assemblies where you can't access the separate cells.

I usually remove my batteries when they reach a full charge. That seems to be the safest and most reliable approach. Some charges continue to leave a trickle of charging current to keep charged batteries topped up but can make the batteries overheat if the trickle charge is too high. Other chargers simply deactivate the charging circuit and disconnect the batteries electronically. However, electronic switches sometimes allow a small amount of discharge current to leak from what were fully-charged batteries.

[JKSeidel]

I use a PowerEx MH-C204W for charging my flash's batteries (NiMH) and the manual states this about refreshing:

"A unique function of this charger is the ability to rejuvenate aged or poorly performing batteries by subjecting the batteries to a conditioning algorithm that first fully drains the batteries and then recharges them.

Battery rejuvenation is recommended once for every ten charges. It is also recoomended for batteries that have not been used or charged for more than 30 days."

After indicating a complete charge, it drops to a 50 mA trickle charge to 'top off' the batteries.

[JDArt]

Originally Posted by bauerman

If you really want to "top it off" - you are going to have to leave it on the charger for some other prescribed amount of time - that may vary by camera and charger model - check your manual for exact times.

Jared

I've never seen a manual that addresses the "top if off" issue at all.

[JDArt]

Ah, thanks for that. My mistake.

[dmacgee]

I have the Maxxum 7D and I normally let the batteries stay in for little while after the light goes out. I've also picked up several extra Li-ION batteries from e-bay and rotate them through the camera on a regular basis.

As a back up I also have the vertical grip which also accepts 6 AA NiMH batteries and I've taken to carrying 2 sets as a backup, I can also use them in my flash if I need to.

I find that the rechargeable batteries do tend to gradually drain while not being used so you may want to check your extra battries from time to time to make sure they still have sufficient charge.

Dave