charging smart batteries

[3Jjb4Skoot]

I have a dynamite passport ultra 2 charger, I don't believe it's a smart charger. Correct me if I'm wrong. Would it not benefit me buying a
spektrum 3s 5000 100c smart battery if I don't have a smart charger ? I'm willing to pay for a quality battery so any recommendations on
a good quality performance battery. I have a SW v2
One more thing, will my stock 120a esc handle a battery with 135c ?

[tbonemcniel]

1. You don't need to have a smart charger to charge a smart battery, you just won't be able to take advantage of the smart features.

2. Quality batteries are kind of black magic to people new to RC boats. The advertised C ratings of different batteries by manufacturers are ALL made up. There is no accepted industry standard by which to measure the C rating. One manufacturer's test may be much less stringent (therefore resulting in a high C rating) than another manufacturer with a more difficult test procedure (resulting in a lower C rating). But if you compare the two on the same test, that battery with the "lower" C rating, may perform better than the one with the "higher" C rating. There's no one to hold the manufacturers accountable for their widely varied ratings either. The only way to compare, is to run all the batteries on the same third party test, which someone has done! That testing showed that the best of the best batteries only performed at 45C, while some batteries that claimed 120C only performed at 20C. That's a big difference. So all the manufacturers lie and exaggerate, the question becomes who exaggerates the most? Company A may be boosting their ratings by 60C, while Company B is only boosting their ratings by 25C, so while both batteries claim 70C on the label, exposed to the same test, Company A's battery is only 10C, while Company B's battery is actually 45C.

My favorite battery's to run are the CNHL G+ 70C/Speedrun 90C/Black Series 65C, as well as Turnigy Graphene Panther's. The CNHL's are usually significantly cheaper and they have sales all the time, and discount codes are available online. I probably have 35+ CNHL packs I run in all my boats.

3. If you're worried about an ESC being able to handle a battery with a certain C rating, you don't quite grasp how these electronics work. If the battery always put out whatever it's C rating is, then your ESC would only be rated to a 5,000 mAh 24C battery (5x24=120). You can take your motor, put a small prop on the boat, with 5,000 mAh 135C batteries (supposedly able to support 675A of current), and the boat may only pull 50A. You can take that same motor and ESC, with only 5,000 mAh 50C batteries (supposedly able to support 250A of current), put a big prop on it, and pull 200A and smoke that ESC, despite the lower C rated batteries. Why? Because the batteries and ESC don't "push" current draw. They simply supply what is demanded. They are rated for what they can deliver or supply current wise. It's the motor that demands the current, based on the load put on it, and the ESC and batteries will deliver what is demanded by the motor to the best of their ability. If setup right, the motor's current demand is less than the ability of the ESC and batteries. Setup wrong, the motor's current demand is greater than the ability of the ESC and batteries, and things get smokey. How much current the motor demands, is primarily based on the load put on it. The larger the total pitch of the prop, the more drag by the hull and hardware, the heavier the boat, the higher the load put on the motor.

It's a lot to take in, I know. Long story short, buy either two CNHL 3S Black Series 5,000 or 6,000 mAh packs, or a single CNHL 6S Black Series 5,000 or 6,000 mAh pack, put good quality connectors on the ESC and batteries (EC5 minimum, I prefer EC8 or QS8), don't go overly eager with the prop, short tests and temp checks after making changes to the boat (especially propping up), and enjoy your boat!

[3Jjb4Skoot]

Thanks for the wisdom, I got my homework cut out for me.

[Mike W]

Awesome post Andrew!

[3Jjb4Skoot]

So I got cnhl black series 5000 3s 65c (2) and got to run it this afternoon. I was impressed, I was under the assumption that you had to pack the (C's) in order to get the performance.
So I'm not going to keep trying to make it faster. I got all stock except for upgraded cooling and a 45x19 prop. So, I'm just learning to get faster in the turns (oval) and enjoy it. Thanks for the help !

[tbonemcniel]

So I got cnhl black series 5000 3s 65c (2) and got to run it this afternoon. I was impressed, I was under the assumption that you had to pack the (C's) in order to get the performance.
So I'm not going to keep trying to make it faster. I got all stock except for upgraded cooling and a 45x19 prop. So, I'm just learning to get faster in the turns (oval) and enjoy it. Thanks for the help !

Good deal! If you get the urge to go just a little faster, try the 4514. I?ve done some measuring on those props, and the ?4519? is actually more like a 4512, it?s total pitch measures at 53.8mm, which divided by its diameter of 45mm equals 1.2 pitch ratio. The ?4514? is slightly faster with a measured pitch of 59mm, giving it a 1.31 pitch ratio.

Of course a real prop, such as an Octura M445 measures out to a pitch ratio of 1.46 on my pitch gauge.

[3Jjb4Skoot]

Sounds good, thanks for helping me out with the ins and outs !