NIMH batts,What am I dong wrong?

[k9hooligan]

Ive been running RC for years.
Ive also been struggling with getting a propper
charge into my NIMH batts.

I use 3000 to 5000 mah,Im using a Venom Pro Charger.
Ive set it from 1amp to 5amps,and I routinely fall way
short.

The setting on the charger are correct,for a 3K mah pack
ill set it for 3amps,and hit go.It will charge to maybe 100
200,maybe 250mah and then shut down..

Same results for the 3600 and 5000 packs. The voltage is
set for 7.2V..

It leaves me fustrated as hell when Ive got to charge a 5K mah
pack 130-150 mah at a time..Knowing Im not getting the juice
into it,And knowing Im not getting the power Out of it on the
other end..

Ive read all sorts of mixed reviews on the charger.

Should I be discharging my NIMH packs, Or would zeroing them out
kill them.

I dont race,I run for fun.But Aint no fun running with out the juice flowing..

If theres a thread or threads I can get pointed to,please show me the
way and Ill learn to fish..I dont want to just be repeating others woes..

[integra22t]

it sounds like you have a bad cell .. i take it its a stick pack .. one way to tell is discharge it hard 30amps and the bad cell will get hot faster than the rest

you can cut out the cell ..replace it and equlise the cells and recharge the pack

discharging packs to 5 volts is ok but dont take them to zero .. if you do let them sit for 6 hr before charging

[Rootdown4594]

I've fixed packs that had that problem by putting them through multiple charge/discharge cycles.

[RC10th]

When cells get old they don't take charge well, have you tried re-peaking them straight after? Cold cells can also sometimes false peak. If you know all of the cells are good you can try changing the peak sensitivity (if your charger has that feature)

Watch the pack voltage as you charge it, it should steadily climb before dropping off voltage. If it spikes quickly and cuts off you have a problem cell.

In the old days we used to "zap" problem cells that were iffy with 12v. It would break up crystalization on the electrodes.

[k9hooligan]

Thanks,Ill try adjusting the peak sensitivity..Im not noticing any individual cell getting hot,mostly the entire pack heats up....They seem to do better when I leave the Amperage going in low,around 1-1.5 or so..Ill leave the next discharge hooked to my digi multimeter to monitor the voltage,then stop when it hits the 5v area..

May be time to get new packs,maybe I did not give them a propper break in period..These packs are a couple yrs old..But Ive not run them that hard..Ill order up a couple new packs..

I want to go LIPO,but hell,,I thinks i need to get NIMH right first..

[Tamiyaterror]

you cant really get lipo wrong to be honest, once you go lipo youll never go back.
as above i used to have similar problems, mine was mainly due to false peaking of the cells, caused by one dodgy cell. my advice, get some lipo's.