Why do you use HV and / or why don't you?

[Terryscustom]

Sounds like a charging issue, not a battery issue. Check out BuddyRC for a parallel board and charge all your A123 at the same time. So much faster that way.

No charging issue, I have four Celpro chargers and two dual chargers from @Taildraggerrc , just some events don't have power and so you charge at beer o'clock and swap batteries during the day

 

[DeathHorse]

I'm confused then...how is running HV through a reg going to be anymore convenient than just charging more A123/Life?

 

[Terryscustom]

Sorry. Guess it was a dumb question.....

 

[DeathHorse]

I sure didn't mean to make it seem that way...thought maybe you were future proofing and buying lipo/LiIon for a HV setup later..

 

[Terryscustom]

I sure didn't mean to make it seem that way...thought maybe you were future proofing and buying lipo/LiIon for a HV setup later..

Nope, sorry. Nine 30-42% planes in my trailer / garage and 80-90 gallons burned a year on average so just bringing up the subject. After breaking out of glow and NiMh days I settled into A123's and just kinda stayed there. Now that price is down and choices are up on HV servos thought it was worth a re-look.

 

[Xpress]

LOL, sorry, just found these two things from the same person regarding lipo's as funny.......in a joking non FG giving you crap kinda way.

I do have to say that I am tossing around getting a Fromeco regulator and a couple of LiPo's from glacier just for when I go to events. Seems that a typical Huckfest weekend is 7-8 gallons of gas and I have to admit that 10-12 flights on a couple of 3000mah LiPo's is attractive to me. Having 4-6 A123's to charge compared to two LiPo's or two Lions is why I started the thread.

I don't get it... (maybe because I'm tired). Lithium creates its own oxygen when it burns, so it needs to be smothered. A Class D extinguisher is copper based so the copper inside of it basically melts to the lithium and chokes it out.

 

[Xpress]

Sounds like a charging issue, not a battery issue. Check out BuddyRC for a parallel board and charge all your A123 at the same time. So much faster that way.

I never recommend parallel charge boards. Every cell has to be at nearly the same voltage, otherwise the charger can overcharge one cell, or not fully charge another cell. This can easily create a fire situation, and single channel chargers are only designed to charge 1 pack at a time. If you need to charge multiples at a time, then I'd recommend a multi-channel charger, like the Hitec X4 AC+.

 

[Terryscustom]

I don't get it... (maybe because I'm tired). Lithium creates its own oxygen when it burns, so it needs to be smothered. A Class D extinguisher is copper based so the copper inside of it basically melts to the lithium and chokes it out.

Just giving you some ribbing because you said you never have seen LiPo issues but you later posted info on putting them out. Just caught me as funny, but I know what you are saying. I've only seen two LiPo fires at events and both were clearly asking for it with their process.

 

[DeathHorse]

I never recommend parallel charge boards. Every cell has to be at nearly the same voltage, otherwise the charger can overcharge one cell, or not fully charge another cell. This can easily create a fire situation, and single channel chargers are only designed to charge 1 pack at a time. If you need to charge multiples at a time, then I'd recommend a multi-channel charger, like the Hitec X4 AC+.

Parallel charging is great BECAUSE every cell has to be the same voltage not in spite of it. When two lipos are connected by the main leads they quickly equalize pack voltage over a few seconds and maintain the exact same pack voltage from then on. Not an average, the same voltage. Series connections can create the problem you referred to. This is why we use balance leads. Without them the charger only knows the total pack voltage.

After connecting the main leads the balance leads can be connected and then every corresponding cell between the packs equalizes to the exact same voltage. Through regression to the mean this basically balances your packs without the charger having to do anything. The more packs hooked up, the more accurate the regression to the mean.

The issue with parallel charging is the lipos will equalize voltage so fast the amp spike can melt leads or charge one battery too fast during the initial hookup. This is only a problem if a person accidentally connected e.g. a fully discharged and storage charged lipo or connected the balance leads before the main leads.

The charger can never charge one cell or pack more than another because in parallel they will always be the same voltage. Each pack will get exactly what it needs to reach 4.2v.

Edit: My Cellpro 6 is single channel and clearly designed to be used with parallel board. It has parallel settings in the firmware. I'd never be able to use the 40 amps it puts out without a parallel board. (All the parallel settings actually do is calculate the amperage on a per pack basis in the initial setup for a charge. It charges exactly the same whether you use the parallel option or not.)

 

[Bill Vargas]

I've recently gone HV on my new 50% YAK. Crisp control on all surfaces no doubt but I find myself dialing in more expo than I normally would use on a standard 5.5 to 6 volt airplane.