Chris Briggs
25-06-2009, 07:37 AM
Good morning,
My boss decided to purchase a remote control car for his son (first car). With little research we ended up having to take what the local model shop had in stock. The car is a Traxxas 2wd stadium truck and is great. The problem is the batteries! He bought a 4500mah battery and borrowed a 3800 one from myself. The day after the present fest, the complaint was my battery was great but the new one just gave no run time. I discharged it to 5.4V with my much more charger then charged it at 4amps, 5mV delta peak with a temp cut off at 40degC, it peak cut with only 3300mah (this is a 4500mah battery). I discharged it and charged it another few times, making sure the battery was cool between the cycles and still only 3300mah. So we took the battery back and swapped it for a 4600mah intellect pack. I put it on my much more charger and cycled it a few times with the following results:
Charge 1: 1200mah in, 2amps charge rate, initial charge to get it to life
Discharge 1 : 948mah out
Charge 2: 4500mah in, capacity cut (for got to set it a little higher than battery capacity)
Discharge 2: 3400mah out
Charge 3: 3400mah in, peak cut
Charge 4: 315mah in - re-peaked battery to see what would go in
Discharge4: 4174mah out
Charge 5: 3300mah in
Now my much more 3800 pack takes 3900mah and peaks every single time, is there an issue with these very high capacity stick packs which means they are naff! or do I need to do give them a good kicking at 6amps or something!
Any help appreciated, I have a feeling the local model shop is just going to blame the charger rather than the battery as I have had 2 now but I guarantee the charger is fine as I use it at every weekend on my racing packs for TC and each time it charges the cells to capcacity!.
Thanks
Chris
My boss decided to purchase a remote control car for his son (first car). With little research we ended up having to take what the local model shop had in stock. The car is a Traxxas 2wd stadium truck and is great. The problem is the batteries! He bought a 4500mah battery and borrowed a 3800 one from myself. The day after the present fest, the complaint was my battery was great but the new one just gave no run time. I discharged it to 5.4V with my much more charger then charged it at 4amps, 5mV delta peak with a temp cut off at 40degC, it peak cut with only 3300mah (this is a 4500mah battery). I discharged it and charged it another few times, making sure the battery was cool between the cycles and still only 3300mah. So we took the battery back and swapped it for a 4600mah intellect pack. I put it on my much more charger and cycled it a few times with the following results:
Charge 1: 1200mah in, 2amps charge rate, initial charge to get it to life
Discharge 1 : 948mah out
Charge 2: 4500mah in, capacity cut (for got to set it a little higher than battery capacity)
Discharge 2: 3400mah out
Charge 3: 3400mah in, peak cut
Charge 4: 315mah in - re-peaked battery to see what would go in
Discharge4: 4174mah out
Charge 5: 3300mah in
Now my much more 3800 pack takes 3900mah and peaks every single time, is there an issue with these very high capacity stick packs which means they are naff! or do I need to do give them a good kicking at 6amps or something!
Any help appreciated, I have a feeling the local model shop is just going to blame the charger rather than the battery as I have had 2 now but I guarantee the charger is fine as I use it at every weekend on my racing packs for TC and each time it charges the cells to capcacity!.
Thanks
Chris