View Full Version : Battery Problem question?

09-22-2010, 02:22 PM
First I am new to RC Boats and new to this site.I am just getting back into RC Cars also after being out of the hobby for a long time.I just got an Aqua Craft Brush less that I run 2 NIMH in.The other day after I was done running it the battery had become really hot and split the shrink wrap on it.Are these batteries old to were they are no longer good? I bought the whole setup used.

09-22-2010, 02:49 PM
Nope that whats happens to batteries when you drain lots of amps out of em- get lipos

09-22-2010, 03:12 PM
You can use NIMH packs as with lipos best thing is to have a timer and run and check temps and figure out how long you can run before anything heats up ... and say it's 5min then have a timer set for 5min and you run for only that amount of time and this way you won't burn up anything.

09-22-2010, 04:06 PM
The nihms are prob still ok they will just heat up real hot

09-22-2010, 05:59 PM
What amps should I charge at? There is a selector on my charger.

09-22-2010, 06:06 PM
What amps should I charge at? There is a selector on my charger.

Hi what ever your battery is charge at 1C example :
3000MAH battery 3 amps
3900MAH battery 3.9Amps
5000MAH battery 5Amps
4500MAH battery 4.5Amps
Hope this helps.

09-23-2010, 12:50 AM
I had the same issues with my sv-27. Switched to lipo and gained 5mph, and no heat!! Nimh packs are'nt putting out enough amps to feed that brushless setup!

09-23-2010, 10:12 AM
What amps should I charge at? There is a selector on my charger.

I used to charge my nimh's at 5 amps... also use the best nimh's you can afford.. I ran matched intellect IB4200's in my boats before lipos.... those puppies ran great and didn't have heat problems... they were rate at 35amp discharge rates..

09-23-2010, 12:31 PM
What ever you are running (even though brushless has way more amp draw capacity, ususaly) make sure your battery can put out the power that is being demanded by your ESC and your motor setup.

Once your battery is pushed past its discharge limit, it will heat up. The longer and harder you push it, the faster it heats up and the hotter it will get. Eventually, the heat will build up internal resistance in the batt. and you will melt components. Heat inversely effects conductivity.

Other issues that can cause heat in the battery department are poor connection in your electrical components, small gauge wires, corrosion, and back or inadequate battery to ESC connectors, etc. Maybe convert to dean's plugs if you are running lesser grade plugs.

So check on the discharge capacity of your NIMH's. They are most likely not up to the task of the brushless.

hope this helps.