RC-Monster Forums - View Single Post - ?? Batteries for neu 1515 1yf, quark 125 G2R

BrianG · 06.09.2007, 09:03 PM

The A123 cells have the large advantage in that they are safer than lipos. Even if you somehow puncture the metal can, all they do is smoke. There used to be a video at the A123 website showing this. However, they are a bit heavier and have a different voltage rating than lipos. So, either use their charger, a charger with an adjustable CC/CV threshold (3.6v/cell), or the lipodaptor module.

Yes, they can charge very fast. Being able to charge in 15 minutes means they must be charging at around 4C, where most regular lipos are charged at 1C.

Since you mention an adjustable voltage, I assume you mean that "turbo" module? It is essentially a switching power supply that boosts the voltage. Power isn't free though; if you boost the output voltage, you are going to increase input current. Also, there are losses on that device. Instead of using that device, I would consider simply adding an extra cell or two to get the voltage you want. This will be more efficient and runtime will be higher.

Most people running these in trucks over 6-8 pounds are running a parallel set to get the current and runtime needed. Each cell is only 2.3Ah, but paralleling a pair gets you 4.6Ah, which is much better IMO.

	(#2)
BrianG RC-Monster Admin Offline Posts: 14,609 Join Date: Nov 2005 Location: Des Moines, IA	06.09.2007, 09:03 PM The A123 cells have the large advantage in that they are safer than lipos. Even if you somehow puncture the metal can, all they do is smoke. There used to be a video at the A123 website showing this. However, they are a bit heavier and have a different voltage rating than lipos. So, either use their charger, a charger with an adjustable CC/CV threshold (3.6v/cell), or the lipodaptor module. Yes, they can charge very fast. Being able to charge in 15 minutes means they must be charging at around 4C, where most regular lipos are charged at 1C. Since you mention an adjustable voltage, I assume you mean that "turbo" module? It is essentially a switching power supply that boosts the voltage. Power isn't free though; if you boost the output voltage, you are going to increase input current. Also, there are losses on that device. Instead of using that device, I would consider simply adding an extra cell or two to get the voltage you want. This will be more efficient and runtime will be higher. Most people running these in trucks over 6-8 pounds are running a parallel set to get the current and runtime needed. Each cell is only 2.3Ah, but paralleling a pair gets you 4.6Ah, which is much better IMO.