Lipo noob shopping list.

dogman dan

1 PW
Joined
May 17, 2008
Messages
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Location
Las Cruces New Mexico USA
Ok here's what's on the way from HK right now.

2 6s chargers IMAX B6

4 of the cheap $3.50 low voltage alarms

5 5s 5000 mha Turnigy 30c packs.

Looking for a power supply or two localy, till then I have some sla's to run a charger.

Forgot to get a bunch of connectors for the balance taps. But won't need them till the next order and I have enough to paralell them. The power wires will get andersons. Will be running a 20s pack, with one spare in case one arrives doa.

Not planning on much more than breaking in the packs right away. Then some short ride testing to see what 72v is like, and if I can corner faster than 30 mph. There may be some racing in the fall.

I just couldn't stand waiting much longer to get started, and don't want HK to sell out just when I need lipo.

What else do I absolutely need to have before I run them hard, and where do I get it?

I have the cycleanalyst stand alone, so I can watch watthours and such. The Lyens controller is programable so I suppose I could set a sort of high lvc.
 
She's a keeper. I thought she'd be a bit pissed, but like I said, compared to the last hobby, hot air balloons, this is cheap. And I did finish nailing shingles to the entire roof of the house last week, saving us at least a thou.
 
Not sure where to get it, but full body armor like they use for bear training might be useful, if you actually hook those up as 25s. :p
 
Gonna run 20s, 72v.

If you read the endless lipo threads you see a lot of " one pack came with a dead cell" comments. Like a Vpower HK battery, you have to spend too much sending it back to make a warranty worth it, and no fix without sending it back. So I orderd 5 packs to have a spare. At these prices for 30c discharge rate, ordering an extra or two is no problem. If all come in good shape, I may end up doing something dumb anyway. I have an old truck toolbox in the backyard to use for my charging station in case I do. I understand that charging an overdischarged pack can be exciting.

But since this is going to be a racing setup, 40 mph or more capable, I plan to ride using at least some body armor and good helmet. I found a good place to practice at the local high school football stadium. Good clean pavement, no curbs if I have to swing wide on a corner, and no cars. Should be good clean fun trying to get my corner up to 35 mph. At 30 mph last time, not that many of the other riders were cornering that much faster, so I think 35 in the corners should be good for next time. Easier said than done though! I can start with a very wide 35 mph corner, and gradually get it tighter.

If I do lay it down, the batteries will be inside a stout box of some kind, not just taped to the frame!
 
well from one noob to another I have this low voltage alarm that keeps track of lowest cell voltage drop as well -I have alarm set for 3.3v so if any cell drops, I know it.

GT-Voltage-Ana.jpg


But those are out of stock, HK also has a cheap version of cell log 8 without USB function for $13.57 and shipping is about 6$ If you get two of them.
You might try that? It is nice to know exactly where you cells are at, at any given time.

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10952&Product_Name=Cell-Log_8M_Cell_Voltage_Monitor_2-8S_Lipo

Good luck and it really helps that you document everything here, thanks for that.
 
What chargers did you get? And why?

This is the bit that I wouldn't be confident on, if I was to go LiPo. They seem pretty expensive, compared to my LiFePo chargers.

- Adrian
 
You should consider some of Garys stuff

http://www.tppacks.com/products.asp?cat=26
 
The battery medic is something I use all the time. Allows me to check on the health of my packs and do the occasional extra balancing when needed.

cell-medic-1.jpg


http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10328

If you're also going to go with high current, consider getting 12AWG teflon wire, a BBQ thermometer to put inside the hub and a taper drill set to ventilate the covers.
 
I replaced all the connectors with deans on my HK packs. they have lower resistance than the stock connectors or Andersons. I also shrinktubed the balance taps to the main battery wires. that keeps them from getting snagged or broken inside the battery bag when I ride.


Any of those little battery meters are great to have. looks like they quit selling the Cellpro, but they replaced it with http://www.hobbyking.com/hobbyking/...Cell_Diagnostics_meter_2S~6S_(2nd_Generation)
its the size of 2 quarters, I keep one on the bike at all times just in case I need tho check the ballance or individual pack voltages.

As for power supplies, I was using a discarded computer power supply, but replaced it for something like http://www.hobbyking.com/hobbyking/...Product=6256&Product_Name=12V_5A_Power_Supply

As for the batteries them selves, Lipo deteriorate over time whether you use them or not. you get <=500 cycles, and/or 2 years out of them. Since they aren't your main battery, and you aren't comuting on them, I would use the hell out of them for fun untill dace day. Time will do more damage to them than you'll do using them.

Besides, there's no point racing on equipment you aren't well practiced and failure with.



The LipoGrin is a whole subspecies of the EVgrin. Its much harder to cure. :twisted:
 
Yeah, I was going to get a battery medic, but they are out of stock now.

I bought the imax b6 chargers, cheap enough to get two. Hope I get a few months out of em. Once I get experienced, I'll prob start charging like the pros, but for now slow and safer with the b6.

Once I get to playing with the batteries, I know I'll be ordering something else, so I'll get one of those other battery checkers then. I was under the impression that the led's on the cheap warning buzzers would be enough, but I guess not. I like the idea of running the lvc warning higher than usual on the more expensive lv warners. If the pack is balanced to begin with, would just one be enough? Just assume the other 3 are not lower?

Even if the lipo lasted years, for racing only, 500 cycles would take forever. Even if I do a cornering practice sesh weekly, that's still only about 100 cycles of practice in 2 years. So some sessions using this lipo for dirt riding will make sense, especially when I have 10 ah of 72v.

I have a good spot scouted for practice. Great pavement with no loose shit on the high school football stadium parking lot. A few chalk lines to follow, and bingo, simulate the harder corners on the track. Aside from legal issues, on the street those dang curbs are scary if you go wide in a turn.
 
Chargers arrived, sure seem sophisticated compared to the typical free with the battery lifepo4 chargers. If they last any longer.... I'm so good at frying a charger. Looks like I get a polarity reversed warning instead of pffftt! That'll solve half my charger problems when I wire up plugs backwards over and over.
 
dogman said:
I understand that charging an overdischarged pack can be exciting.

The Turnigy and Zippy packs seem to be very forgiving unlike lipos of few years ago. I pushed mine
to 5v a cell (not intentionally) and no flames, requires upward of 6v for fireworks so you have to get it really
wrong before lithium polymer becomes 'explosive'

KiM
 
What I hear to NOT do is try to charge a pack that has a cell in it below a minimum voltage. I know its best not to let lipo get below 3v, but I forget at the moment if that is the danger level, or just the pack will work better voltage. Time to re read some threads on lipo.

Edit. Never above 4.3 volts. And never below 2.7v. Charge a pack with a cell below 2.7 v in a good place to watch a pack catch fire or explode. Thanks for the info LFP.

I already have an old truck toolbox or two in the backyard that will make a great charging station. I'll use hardibacker tile underlayment for the non conductive surface to put the charger and battereis on. I'll need a warmer for it in the winter though. Mabye charge in the oven in the house in winter, or use an old refrigerator for the charging station.
 
Charging a cell that has sat over discharged was a very common way to get a LiPo fire a few years ago. This latest generation stuff is so much more stable, like Kim said, you've got to earn it to make it go off now days.

The 2.7v-4.3v are very safe and conservative boundaries with this latest generation stuff. I actually did a test with a HC 5Ah cell where I charged it to 4.5v, which put 8Ah into it, and it discharged the full 8Ah and didn't get hot or act funny at all. So, for a race, if you wanted to poke them up to 4.35-4.4v if you're desperate for every last bit of capacity, I think it would be OK. Who knows how many life cycles it cuts off the pack to do it, but for a race pack, cycles don't really matter.

For normal usage, set that charger for 4.125v, and your number of life cycles will increase by a very large margin in exchange for a small loss in energy storage.


As far as 1 piece of equipment you can't life without when using LiPo, I would say the HobbyKing battery medic. I must have one of them laying in every room of my house, and in every backpack etc, and I find myself rarely making it through a day where I don't use them multiple times. Damn slick little devices. They can balance, monitor, alarm, discharge, etc. Very clever little guys.
 
Yeah, I plan on pouncing on some of those( battery medics) as soon as they go back in stock, along with anything else I need by then.

I looked at the TP packs lvc's too, but soldering turns me off. No good at it. But maybe I could trade something for the soldering to somebody.


That's reasuring about the lack of fireworks these days, Charging out in the yard should work fine till cold weather, using the toolbox if raining.

And on that subject, even if it's half a year away, What is considered too cold to be charging lipo? Below freezing? Below 40F? Can you just warm the battery in the house to 70F, and then put it on charge in a freezing place?
 
dogman said:
I looked at the TP packs lvc's too, but soldering turns me off. No good at it. But maybe I could trade something for the soldering to somebody.

?

Gary used to offer ready made boards if you paid extra, IIRC was ~15 for assembly? May have changed now?
I was lucky i received mine all assembled and pre-tested (thanks Gary :) )
Battery medic booster is one i would definitely get, the battery medic is good but if your pack
is only slightly out of whack it takes hours/days to balance, with the batter medic booster it happens
ALOT faster. You already ordered chargers as well right? not sure the boards will be of use
to you, i thought the boards were more for those that charged their pack in same
config they discharge in, i.e if you run 44v setup you charge at 44v If you use and rc charger
you will only be able to charge the packs broken down in parallel config at 22v? I could be wrong
though i often am when it comes to anything electrical :-|

KiM
 
The Goodrum product I was looking at was just a lvc board. Not the bms. So you'd have a proper cutoff, instead of just beeps like the stuff at HK. Of course, for model helicopters etc, you'd never want a cutoff. For now, I have two Imax b6 chargers, but that is just a starter kit.
 
dogman said:
. Of course, for model helicopters etc, you'd never want a cutoff.

Yeah could get messy if you weren't high enough up when the power was cut, rc helis auto rotate reeeeally well but
need a bit of hieght to do it. I used to time my flights 4 minutes of hard flying is about all the pack could take and all i could take TBH haha very
nerve racking want relaxing get a rc sail boat haha

KiM
 
When the cells get to the point the LVC starts tripping, what will happen is that it "hit" the throttle, like a big tuna, when under full load. If you back off the throttle a bit, you can go quite a bit farther, but eventually it will start hitting again, with even a little throttle. At this point, If you just stay on the throttle, it will oscillate on and off, at about a 2Hz rate. With a 10Ah pack, I've seen the LVC first hit when there is about 10% capacity left. I can usually go another couple of miles, before the oscillation starts with any throttle input. When that happens, the pack takes back pretty much the full 10Ah.

-- Gary
 
Sounds like those LVC boards are what I'd want for race day, when a bunch of gassers might make hearing the single beep of the 3 buck HK voltage monitors on the first warning. Those are only pack voltage monitors anyway. Hammering stuff in a race though, I'll want at leas cell level warnings, if not a lvc.
 
Once my lipo arrived, I realized charging outside in 100+ temps might be a bad idea, at least in a metal box that might be 150F.

So looking aroung the house, I realized the fireplace is a pretty good place for fires. :idea: So I'm just using the hearth, and putting the spark screen in front of it. anything really bad happens, I can always poke it into the firebox. I heat the house solar now, and rarely use the fireplace even in winter. As soon as I start charging, I look at the voltage at cell level, and can stop if one is really low. So nothing bad should be happening.

I still need to get a battery medic so I can check before charging. If my charges allow that, I haven't yet learned how, but it is easy to check em at the start of the charging.

I'm liking the chargers. Not sure if they are the best, but they sure are smarter than the ping chargers I've had. I like it that they can charge pretty much anything you have. I haven't tried to adjust the top of charge down some, if it can be. Sounds like a good idea to undercharge a bit, even though I most likely will be losing them to old age, or track abuse rather than cycles.

For a power supply, it's working ok to use an old half dead sla to run both chargers at the same time, while it is hooked up to a dumb 12v 6 amp battery charger I've had for about 20 years. Hooking it straight to the 12v dumb charger didn't work, not good enough current. But once attached to the sla to smooth it out, it works fine.
 
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