ASK Cub Reporter, Version 09.16.2010- A Weekly Q & A Session

Every week we get tons of email, and every week I pick the two that are easiest to answer and use them here! Hehehe
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“Hello,
I was wondering whatever happened to the HPI Hellfire that was supposed to
be the next big monster truck for HPI?
Patrice from Québec”

Cubby– What’s going on up there in the land of hockey, curling, donuts, fries w/ mayo, and high test Molson?

Funny you mention the HPI Hellfire. Last week I was getting some laps in with a guy driving a Hellfire. I still think it’s one of the toughest looking truggies of all time.

About your question. I think a better one would be, “What the hell happened to truggies as a whole?!” For a couple of years truggies looked to be taking over the planet, today, while still popular in some circles, it’s obvious their sales have really dropped off. Why? IMO, the biggest reason is because they look ridiculous, there is no full scale truck (in this solar system) that looks remotely like an 8th scale truggy. Combine that with their high buy-in price point, high cost of their tires, and needing a fairly expensive servo to throw those big tires around, and you just don’t have a vehicle that is going to be embraced by the masses, no matter what brand it is.
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“Hi Cubby big fan, how does a Lipo balance charger work?

Terry G.”
Cubby– Hey ya Terry, thanks for the email.

So just how does a balance charger work? First off, there are basically two kinds of “balance” chargers around now days, the type that only connects to your balance tab (that doesn’t use the larger main positive and negative pack wires), and another type that connects to your balance tab and your batterys main power wires.

In the first case where the balance charger only connects to the batteries balance port, it works by charging each cell separately to 4.2 volts.
Because it is actually charging through the balance tab, these types of chargers typically only charge at a low rate (such as 3 amps or less because the balance wires and connector isn’t made for high current). On smaller capacity packs, such as 1000 mah packs used in 18th scalers, they work really well. But, if you are trying to charge a big 8000 mah pack, it’s going to take a long, long, long time.

The second type of balance charger, the type that uses both the balance port and your main power wires works differently. These types of chargers use the main power wires to charge, and apply a slight discharge through the balance port to even out the cells. These chargers monitor each individual cell voltage, ensuring no cell is ever charged above 4.2 volts (unlike a non-balance charger). Near the end of the charge, a slight discharge through the balance port is used on the higher voltage individual cells. This brings the higher voltage cells down to match the lower voltage cells in the pack, then the charger applies more charging through the main power wires to finish fully charging them all. In the end, it ensures all cells end up at 4.2 volts.
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Send us your questions, comments, rants and raves to Cubby at BigSquidRC dot com!
YOUR Cub Reporter