standard charge or quick charge for nicads?

[Minty]

I have a charger with standard and quick charge features for my 7.2v model
car battery pack. Which charging method is better for the life of the
battery pack, standard charge at 10-12 hours or quick charge at 4-5 hours? I
charge the pack mostly on standard charge with occassional quick charge. My
1800mAH battery pack is still in good condition after 3 years. I seemed to
have read somewhere nicads need to be quick charged from time to time for
whatever reason.

 

[Phil Allison]

I have a charger with standard and quick charge features for my 7.2v model
car battery pack. Which charging method is better for the life of the
battery pack, standard charge at 10-12 hours or quick charge at 4-5 hours? I
charge the pack mostly on standard charge with occassional quick charge. My
1800mAH battery pack is still in good condition after 3 years. I seemed to
have read somewhere nicads need to be quick charged from time to time for
whatever reason.

** What is the make and type of 1800 mAH cells ??

How many charges has the pack had ?



............ Phil

 

[Rob Judd]

You have it right. The only other thing to do to ensure they last is to
occasionally discharge them completely before a slow charge. This tends
to cancel out the "memory effect" which makes their charge shallow.

A resistor across them with a LED in series is usually sufficient.

Rob

 

[happyhobit]

Hi Minty,

The theory is that fast charging batteries conditions batteries for fast
discharge. Also a 4 or 5 hour charge is not fast. A one hour or less charge
is fast.

For an 1800 mah cell. (NOTE: Efficiency isn't 100% so add more time or more
current. 20% to 40%)

Slow charge rate C/10 180ma for 10 hours (12 to 14 hours)

Quick charge rate C/3 600 ma for 3 hours (3.5 hrs Watch the
battery temp.)

Fast charge rate 3C 5400 ma for 20 minutes. (Should be only used
with a 'Peak Charger'.)

Jay

 

[Minty]

** What is the make and type of 1800 mAH cells ??

How many charges has the pack had ?



............ Phil

I'm not sure what make they are. The pack consists of 6 cells each measuring
2cm in diameter and 4cm in height. I replaced the original 1200mAH cells
with these 1800mAH cells which I bought from Jaycar. They're made in China.
They have less than 100 charges. I always discharged the pack fully before
recharging. On occassions the pack was left in the car unused for a couple
of months.

The Nikko charger specifies 3-4 hours for quick charge and 10-12 hours for
standard charge for the original 1200mAH cells.

These days I use the pack mainly to power my digital camera via an external
DC adapter.

 

[Phil Allison]

I'm not sure what make they are. The pack consists of 6 cells each measuring
2cm in diameter and 4cm in height. I replaced the original 1200mAH cells
with these 1800mAH cells which I bought from Jaycar. They're made in China.
They have less than 100 charges. I always discharged the pack fully before
recharging. On occassions the pack was left in the car unused for a couple
of months.

The Nikko charger specifies 3-4 hours for quick charge and 10-12 hours for
standard charge for the original 1200mAH cells.

These days I use the pack mainly to power my digital camera via an external
DC adapter.

** If you get 100 charges from cheap cells you are doing OK.

Buy some Sanyo ones next time.


.............. Phil

 

[Craig Hart]

Hi..

I replaced the original 1200mAH cells
with these 1800mAH cells which I bought from Jaycar.

Your charger is now probably not suited to the cells if it is a basic
timer-based charger - it will most likely be undercharging, unless it is an
intelligent charger with delta-v detection or other intelligent charging
method.

Craig

 

[Mainlander]

I'm not sure what make they are. The pack consists of 6 cells each measuring
2cm in diameter and 4cm in height. I replaced the original 1200mAH cells
with these 1800mAH cells which I bought from Jaycar. They're made in China.
They have less than 100 charges. I always discharged the pack fully before
recharging. On occassions the pack was left in the car unused for a couple
of months.

Modelling stuff often uses a type of cell called a "sub C".