Problem with battery/charger/or user? Newbie

[stecroy]

Hi there i've got a RTR ansmann mad rat, only upgrade so far is alloy suspension. I've got a problem regarding the battery life. i have a ansmann 2000mah pack, which is charged using an ansmann powerpack 6 delta pro. The battery lasts aprox 4-5mins, so i upgraded to a dyna-fun 4500mah pack, i charged and took it for a test, but i'm still getting 4-5 mins run time? am i doing something wrong?? Cheers in advance newbie.

[GRB]

I think that may suggest that your charger is not charging them properly, give the new battery a few more charge/discharge cycles and see if it gets and bettter if not then it sounds like the charger is the problem.

[JCJC]

Times may improve, second battery has twice the capacity of the first, charger charges at .9amp so will take a few hours to fully charge.

Approximate Charge Times:
1000mAh Battery Pack - 1.3 Hours
2000mAh Battery Pack - 2.7 Hours
3000mAh Battery Pack - 4 Hours
4500mAh Battery Pack - 6 Hours

Watch out for the tamiya connectors, they do not work well. And careful not to overheat the motor with long running.

Best advice is find a local club and pop in.

[stecroy]

thanks for the quick replys, so am i discharging/cycling properly? i take the battery off charge when the led changes to green, run the car till its dead (no power to go forwards or backwards, but steering still operates) then i allow battery to cool before charging again. the 2000mah pack has been charged around 6 times which takes 4ish hours, the 4500mah only twice which takes around 6hours. Sorry for the long winded questions, this is my first rc buggy.

[stecroy]

so if it does turn out to be a charger problem, which charger do you guys recommend?

[JCJC]

We think the battery will improve with time/more charges

your system is OK, run battery untill discharged, leave to cool and recharge, the NiMh batteries are much better than the NiCad we used to use, but most of us have moved on to lipo and lipo chargers (we have always used chargers that output 4amps plus and will charge in an hour from flat), bit of an investment for your mad rat, stick with what you have got for now.

You may see a bit more grunt from the larger battery.

[bodgit]

Sorry but your not doing your batteries any favours by running them till they are so flat they can only move the servo.
Most nihm batteries should not be discharged to less than 0.9v per cell. If you are continuously doing this your are buggering them up.
You should just run the normal 5 mins race plus maybe 1 min before and after then let them cool and put them in a balancing board to equally discharge them all to the same voltage 0.9v then recharge them. The way you are doing it now means that not all the batteries in the pack are at the same voltage so the charger will false peak meaning just one battery may be fully charged and the rest way under charged, hence your low run times.
Next time you flatten your pack measure the capacity of each cell with a volt meter and you will see the difference in all the cells. Buy yourself a decent discharge board, should be plenty around pretty cheap now most people have gone lipo. Also get a better charger, pm me if you want a decent nihm charger.

[sparrow.2]

Don't panic about the above thread. It sounds like you are using stick packs, so a balance board will be useless.
The budget packs are ok to be run fairly empty but I would stop running as soon as you notice a drop in speed or acceleration and then set the pack away to cool. Maybe investing in a fast charger would be good so that you wouldn't have to wait 4-6 hours between runs.

You might want to consider investing in a set of ball bearings too, which will reduce wear to the car and give you longer runtimes as well. Check that everything runs smoothly as a tight rear wheel for example can cost you dearly in terms of runtime.

Are you getting these runtimes on a track or on grass/dirt/tarmac?

Ansmann does acouple of budget chargers well capable of fast charging your packs but keep and eye out for chargers with an integrated balancer should you ever want to get lipo batteries.

[stecroy]

ok cheers for the replys, lastnight i charged both batterys, and run on short grass, i got 2m.15s from the 2000mah and 1m 36s out of the 4500mah??? something is not right but really dont know what? but if i stopped using it after the initial power loss like you suggest i'd only get seconds of use???? gonna get a fast charger tommorrow and see what happens. Cheers for advice