Discharge levels?

[ClydeBuilt]

Been faffing around with the charger and noticed you can change what voltage you can dishcharge the pack to, I use the usual 4 cell pack in the mardaves, so what should I be discharging to per cell ?

[stox217]

per cell i do down to 1v now lower so down to 4v for the whole pack

[ClydeBuilt]

Cheers buddy...I know there oldies, but hey...when its all you have!

Trying to cycle them over the next few days for sunday.

[stox217]

nimh's or nicads?

[ClydeBuilt]

Nicads...of dubious vintage & assorted amperage.

[stox217]

with them you can take them down to 0v or flat flat :thumbsup:

[ClydeBuilt]

Really??????

[Battle_axe]

Really??????
0.1 v if in a discharge tray i would say 0.5 on the charger incase of unballanced cells

[stox217]

yes for nicads as they have no memory as the nimh's do hence nimhs are down to 1v any lower then your risking killing the cell

[ClydeBuilt]

I think mine have only ever been down to 5v or so, would that give me reduced capacity/punch when I charge em?

[stox217]

if there 4cell packs then they should be fine

[bodgit]

If you can get a trinity dpd it will tell you
the capacity left in each individuel cell
the internal resistence of each cell
the remaining runtime of each cell.
You can set the voltage cut off 0.9v/cell is best
display is good with all the info you need.
you can discharge 4-6 cells and stick packs too.
You should be able to pick one up on ebay. Its powered by 2 AA batteries which lasts for ages.

http://i988.photobucket.com/albums/af10/bodgit_2009/th_bdpd-xsmall-anim.gif

[ClydeBuilt]

Handy looking little gadget that!

As you can tell Im still a noob at this, my nicads just dont seem to have any punch or staying power, even for a 5 min race and I was wondering if it was down to charging/discharging.

Ordered some new ones from Kamtec on Wednesday, but its looking like Im going to be let down for using them for sunday now...rather late!

So what would you recommend doing with brand new packs?
Do I just charge'n'go, or slow charge or a set of slow charge discharges?
Im sure I seen somewhere that there was a recommended procedure for new packs to get the best performance from them.

[mdb_75]

yes for nicads as they have no memory as the nimh's do hence nimhs are down to 1v any lower then your risking killing the cell

I thought Nicads had more of a memory than Nimh's -we used to have to discharge Nicads using 12volt bulbs before recharging then back in the 80's! :woot:

[bodgit]

With any pack of single cell batteries each battery has a different capacity. You can buy a matched set which have very close readings but even these if you dont look after them will slowly become unbalanced.
After each race I used to leave a day for the batteries to settle then discharge them to 0.9V/cell on a trinity dpd..This would read the values of each seperate battery before discharging began so you could see how close or far they were from being equall. The dpd would then discharge each cell individually down to 0.9V or whatever you set it to.
the benifits of balancing them this way is when you recharge them they all start from the same level.. and reach peak at the same time.. With an unbalanced set the cell with the highest voltage would set off your peak detector and cancel charging leaving the rest of the cells undercharged, this is why you are getting poor run times.
Best thing you can do if you can afford it is to go lipo. They dont need discharging thus saving you time. They last longer than round cells and give way better performance. You can find threads on here giving better advise than I could give you on lipo but its the way to go.