New battery pack - charging question

[SeanD]

I am about to make a new 6 cell saddle pack with sub c cells @ 4500 mAh (NiMH)

I've been doing alot of searching on both the Net and in this forum about the best way to do an initial charge on NiMH batteries. It seems like there are many differeing opinions - some say trickle charge the initial charge while others say go with the max amps the pack can take.

Any opinions on the best way to condition this new pack?

I am using a Integy 16x4 charger.

Thanks.


Integy 16x4 charger

[saul]

if your gonna use it for crawling...and u have the time to kill


charge it at its lowest setting u can with your charger

the slower the first few charges are the better your pack will be

a slow charge creates little heat wich will alow the battery to take a better charge

[binaryterror]

For a Sub-C I'd say 1 amp is ok for a first charge...personally I never break in cells...run them like they are going to be always run. Sub-C's take alot of Amps...I've seen people in racing push them to 10amps regularly. This adds a bit of power but you lose a bit of run time.

For average charging that type of pack is fine at between 1-3 amps depending how long you want to wait.

[Mortimer Snerd]

I'd do the initial charge at no more than 100mah. Don't know why, but I've seen people screw up packs by charging them too high initially.

[Hordsak]

I'd like to know which axles you plan on fitting the Sub C saddle pack on. I just bought a 6 cell Intellect Sub C 4200 stick pack yesterday, ripped it apart and made a saddle pack, only to find it won't fit without the tires rubbing on my AX10's front axle. I had to rip the whole thing apart again, and mount it in an upside down U shape over my servo. Kinda pissed about that. I'm charging it right now with a 300ma wall wart adapter for about 16 hours. I'm usually in no rush to charge my batteries, so I take it slow and easy whenever I can (witch is the case 99% of the time)

[SeanD]

I will putting the pack on my WK axle. I don't have any new pictures but I've moved my servo from the side to directly over the diff pumpkin. In this picture, you will see my new shock mounts. Well, I will be bolting a small aluminum plate on top of this as a mount for 1/2 of the battery pack. It might not look like it in the picture but the 1/2 pack (three batteries in pyramid formation) will clear the tire, the steering links and shocks - that just about covers all possible interference.



I can post pictures when I get it done, if you wish.

Wish me luck.

[Stormin2u]

Originally Posted by saul

if your gonna use it for crawling...and u have the time to kill


charge it at its lowest setting u can with your charger

the slower the first few charges are the better your pack will be

a slow charge creates little heat wich will alow the battery to take a better charge

X2 I agree 199% slow and long will give you the best reasult.

[JeremyH]

http://www.batteryuniversity.com/partone-11.htm

[SeanD]

Originally Posted by JeremyH

http://www.batteryuniversity.com/partone-11.htm

So according to Battery University:

"New nickel-based batteries should be trickle-charged for 24 hours prior to use. Trickle charge brings all cells to equal charge level because each cell self-discharges at a different rate. Trickle charge also redistributes the electrolyte to remedy dry spots on the separator brought on by gravitation of the electrolyte during long storage."

and

"Nickel-metal-hydride should be rapid charged rather than slow charged"

Sound right?

[JeremyH]

You should read the sections. It seems like you took one statement out of context.

[SeanD]

Originally Posted by JeremyH

You should read the sections. It seems like you took one statement out of context.

Sorry but my post came out the wrong way. It should read:

For the initial charge: "New nickel-based batteries should be trickle-charged for 24 hours prior to use. Trickle charge brings all cells to equal charge level because each cell self-discharges at a different rate. Trickle charge also redistributes the electrolyte to remedy dry spots on the separator brought on by gravitation of the electrolyte during long storage."

For subsequent charges: "Nickel-metal-hydride should be rapid charged rather than slow charged"

I did not intend for them to show the Battery University giving conflicitng info.

Sean

[JeremyH]

That is how I charge my NiMH batteries.

[Chris_The_Battery_Man]

The first few charges you want to charge slow at 1-10th the rate (45mah) then after that you can do up to about 6 amps. But the slower the better always...

[SeanD]

I just finished making the pack. Soldering was pretty painless. I popped the pack on the charger and its currently (pun intended) chugging along at .5 amps.

Update at 11:00

[SeanD]

Update:

The inital charge at .5 had the charger stop at around 2800 mAh (according to the charger) even after I repeatedly tried to restart the charging process.

I ran the battery down in the truck and recharged again at .5. The process stopped at 480 mAh but once I set the amps to 1 and restarted, I managed to get 4260 mAh. I am guessing that subsequent charges will increase in capacity.

Here is a picture of the mounts I made for my WK axle:



Here is the battery pack mounted. The cells are held together by Goop and electrical tape (each cell was already wrapped when bought) The black caps you see on the ends are 1/4 neoprene rubber to protect the wires, soldering and to provide impact resistance from the rocks. This rubber is tacked on with Goop. The cable ties hold the pack very securely - no movement whatsoever.



Sean

[Ced RC]

I really like how those packs turned out, and how they mount, great work
The neoprene is a nice touch also.