battery , how to's

[byron westman]

Hi guys, i just got my electric parts for a p spec tunnel and i was wondering if someone could put together a step by step on how to start with lipo batteries ? this is my first fe boat and don't want to start a fire . things like first charge ,storage , balance charge and how to maintain them.

thanks

 

[Kris Flynn]

For Me:

First 5 or so charges, make sure you dont use more than around 60% of capacity

Store at around 50-60% in Ammo boxes or lipo Sacks

Always charge with a balancer

 

[HTV Boats]

Definately balance charge your batteries every time. After the last run of the day I bring them up to 3.9v per cell which is the recomended storage charge. Get a digital infrared thermometer and a cell meter. They are cheap and will give you instant knowledge during the running day. 130 degrees and under is normal and 150+ can be bad. DO NOT let cells go below 3.0v per cell. Most ESC's have cut off voltages programed in. Lipo bags are cheap. I store mine in bags in a metal fireproof strongbox made to store documents. These safes are inexpensive and peace of mind for household storage. I also have an old metal filing cabinate that is again overkill but lets me sleep at night. Bags are a good idea while charging but I don't see many used at races. I think fires and explosions are possible but a minimal risk as technology is improving. Due diligence and good practices will work well. Read some threads in the lipo section of the Offshoreelectrics forum and you will learn a lot and be fery comfortable with these batteries. You will have a male & female end on your batteries. I use 6.5mm castle conectors and use a short piece of large fuel tude I call a diaper over the male battety terminal fto insulate it for handling and storage as if you touch them together you get a big spark. My car battery ran down from charging and not running the motor and on of the guys in the pits took a 4s 5000ma pack and jump started my car. Cranked it over no problem. If I lived up in MN again I'd keep one in the trunk for emergencies.

Mic

 

[jayt]

There is no need to balance charge every time, it's simply not necessary (except with poor-quality packs - one way to identify lousy packs is how well they remain in balance). I have been racing LiPos for over five years and have won a lot of races and set a few SAW records - and I have never charged through a balancer. My packs last for years, but of course I do have balancers. I check the balance of each pack after every run with a LiPo voltage meter (you will need one eventually, now is a good time to get one) and as long as the cells are within 0.02 volts of each other I charge them. Over 75% of the time they are within that range, which is the most commonly recommended maximum variance within a pack. If a pack is out of balance I'll clip on the balancer for a few minutes prior to or while charging. Most club members follow the same technique and our packs last and give outstanding performance. Since I do not buy cheap Chinese packs I can't say if this technique works for crap cells or not. I can say that for many Limited boats the cheap cells seem to work okay.

The risk of fire is almost zero today if the LiPo user buys a quality charger and decent cells - another reason to buy quality. The only burning LiPos I have seen were in boats which were over-amping Turnigy-type cells - really nice fires BTW. The only charging fires I have personal knowledge of were cheap Chinese packs charged without being watched. The stories you read about burning cars and homes down were almost all with old-tech cells and chargers.

LiPos should not be discharged lower than 80% of their capacity, 3.0 volts per cell is really too low. What will happen if you do over-discharge them? The least problem is they will lose capacity. The worst problem is a fire with cheap cells. Store your packs between 3.8 and 3.9 volts per cell if they will not be used for more than a week or two. Storing at full voltage isn't really dangerous but can result in loss of capacity of the pack.

Keep the power lead connectors covered with something non-conductive to prevent shorts. Store LiPos below 80*F. If they get wet, cut off the shrink wrap (carefully!) and dry them out fully, then put on new shrink (OSE sells shrink, buy a couple feet to have on hand). Really, LiPos require less maintenance than the old nickel cells did as long as you are careful with them. They last longer in high amp draw applications and their improved performance is worth it. For those who say that nickel cells didn't cause fires, see below.

 

[John Seybold]

I'm also starting my first FE boat, which brands of batteries do guys use? I've been searching and there is quite a few brands and price ranges. I'm assuming that the expensive packs are better then the cheap lipos, but was looking to find a happy medium. I'm not going to be racing the boat, just playing around at the pond.

Thanks

 

[raptor347]

GrimRacer Speed Packs for my 2S and 4S applications. Hyperion for the other stuff.

 

[HTV Boats]

http://www.hobbypartz.com/gens.html

I have Turnigys,Zippys,Hyperions,Grimracer and Gens Ace seem to give great performance. As to never balancing well if you have the capability it would seem to me better than not balancing. Safety, well your call but best practices will insure less chance of accidents.

http://www.allerc.com/batteries-lithium-polymer-batteries-hyperion-premium-lipoly-c-3_4_93.html

If you can afford them Hyperions are the established top shelf. What you will get is many more cycles and cells that you can abuse a little.. Cost per run will probably equal out. Your money and even the cheap ones power you pretty well as technology moves forward.

 

[jayt]

As to never balancing well if you have the capability it would seem to me better than not balancing. Safety, well your call but best practices will insure less chance of accidents.

You certainly need to read my post more carefully - I clearly stated that I balance my packs when necessary. There is zero compromise with safety and I would appreciate an apology for inferring I would recommending an unsafe practice. :angry:

I run mostly Hyperion and ThunderPower packs. The latter cost a bit more the first time, but replacements cost about 40% less since they accept your old packs as a core credit. This makes subsequent packs reasonably cheap.

.

 

[MarkTanski]

I do pretty much the exact same as JayT, the only difference is I balance them before going to the pond, I never balance charge at the pond. I also just leave my charger set for 10 amps, so my charge rates are all over 1c, some packs it's 2c.

I agree with the idea of buying quality backs, Zippy and Turnigy are not in the same league as good packs, Oddly enough the one pair of Gens Ace batteries I have are pretty good batteries for cheapies! Much better than the cheap packs I started out with. Mind you they have only been used in a bone stock SV27 and a Motley Crew until a put a Castle motor in it! SO they haven't really seen any huge amp draws for 5300mah 30c packs. I'm not sure how they'd stand up to they loads they would see in an open class setup. P Spec is by far our most popular class, both in hydro and mono.

One of the guys here charges his 5000mah 30c Zippy packs at 2c, has been for over a year and has had absolutely no problems with batteries. I don't suggest this with these batteries,but he is doing it successfully.

I've had far fewer issues with batteries (like none) since I began using lipo, I started racing carpet cars during the winter back in the 80's, those were the Ni-Cad days, I've been following and charging high end batteries for RC use for well over 25 years! Lipos are the best and safest battery I'd have to say I've used in RC.

 

[HTV Boats]

As to never balancing well if you have the capability it would seem to me better than not balancing. Safety, well your call but best practices will insure less chance of accidents.

You certainly need to read my post more carefully - I clearly stated that I balance my packs when necessary. There is zero compromise with safety and I would appreciate an apology for inferring I would recommending an unsafe practice. :angry:

I run mostly Hyperion and ThunderPower packs. The latter cost a bit more the first time, but replacements cost about 40% less since they accept your old packs as a core credit. This makes subsequent packs reasonably cheap.

.

I apologise for a gramatical error. I Should have made a new paragraph when starting the "satety" sentence. It was in no way directed at you.

The "NEVER " statement was put in bold print for impact and then you qualified it saying you have balancers and check balance but don't balance while charging. This thread started with a new guy asking for step by step instructions to get started with lipo's and I just thought never was emphasized a bit more than the rest of your comments. No need to start a pi$$in match lets just stay on task and help this guy out. To recomend always balance in my mind was prefferable to "NEVER". I really hate to post on here as when the purpose is to share information gets overshadowed by everyone getting their panties in a wad over interpretaions. My name is on my information and when I direct anything at one person or use quotes I sign my full name. I have no idea who jayt is so to apologise to an avatar is not going to happen.

Mic Halbrehder

 

[Jeremy Linney]

Lipos are only as dangerous as the people who use them. Used them as intended by instructions that should come packaged with every Lipo you purchase and you will be set. Storage voltage varies from manufacturer to manufacturer so be sure and read included warnings and use safely. Have been using them for years and have never had a thermal event yet, lol.

 

[osracer]

Mic, I've just started doing some fast electric and we had a speed run last week. I used it as a test session and my Grim Racer packs were two miles an hour faster than my Turnigy's. The packs didn't have a fresh charge on them but had only sat for a couple days so it probably wasn't a true test. To make a long story short if everything is the same can one brand be faster than another?

Thanks Bill Wachtler

 

[SeanKewley]

Some hold voltage better than others, which could be perceived as a speed advantage.

 

[HTV Boats]

Mic, I've just started doing some fast electric and we had a speed run last week. I used it as a test session and my Grim Racer packs were two miles an hour faster than my Turnigy's. The packs didn't have a fresh charge on them but had only sat for a couple days so it probably wasn't a true test. To make a long story short if everything is the same can one brand be faster than another?

Thanks Bill Wachtler

We have had some batteries that fall off after a couple laps but stay level after that. Seems the initial lap is always fast due to a peak after charging. Hyperions seem to hold voltage best through a run but the Grimracers I have also seem to stack up well. Turnigy's are not neccesarily bad but you get what you pay for. One of the guys on Offshoreelectrics forum with his testing felt Gens Ace were very good and I would say they are also good. 40C is going to outperform 30C too. In the pit area at the Valdosta SAWs Hyperion was predominant. I am not sure but there are probably very few manufacturers making cells. The difference is quality control and assembling good or better cells then putting your brand on it. There are different grade lipos probably made in the same factory. .

Mic

 

[osracer]

Thanks Mic. I appreciate the info Bill

 

[ken turmon]

You could argue the issue of quality till your blue in the face. The simple truth is there are TONS of people using lower priced chinese packs with no issues at all. Starting out in fe or any hobby for that matter is quite expensive. Dont feel you have to go out and lay out a bundle of dough for big name packs. Are they better? some of them most def are. Are they $200.00 better? I have my doubts. Racers who want every last ounce of power may be justified in spending the dough, as for the average boater Its not needed IMO, I know I won't be forking out the money for big name packs until i see proof that there is a $200.00 dif in their performance.

 

[lohring]

I think the quality of packs comes down to what current draws you are running. The better the packs, the lower the internal resistance. This will always matter, but you really start to see the difference at high currents since the heating is proportional to the resistance times the current squared. In the spec classes, you can get away with lower quality packs for club racing. There the currents are under 100 amps with spikes to 130 amps or so. My 15 mohm resistance packs get pretty warm, but so do the wires. I get consistently beaten by a racer running better quality packs among other things. You will need the best (8 mohm packs) if you expect to win at the national level or set SAW records.

Lohring Miller

 

[ken turmon]

How do you measure a packs internal resistance.I have been tempted to hook up my voltage meter to try and measure but im not sure they are designed for that type of resistance measuring. It would be cool to know the ir of the packs I have. Also what is concidered to be low...

 

[raptor347]

I know my Hyperion chargers give pack resistance at the end of the charge cycle. It's great info to keep tabs on pack condition.

 

[HTV Boats]

I know my Hyperion chargers give pack resistance at the end of the charge cycle. It's great info to keep tabs on pack condition.

I think we have addressed Byrons initial question on starting out and maintaining Lipo's. Raptor's post brings up another very important component, chargers. In my experience if you are going to have more than one FE boat get a good charger. I got my Hyperion Duo used and it's only drawback is it is DC only. But being 12-25v DC input lets you used charged packs you want to bring down a bit to storage voltage to charge other packs. It charges any type of battery and gives you more info on packs than you need, plus charges two different bateries at the same time.Since my son and I both run it is a must to have that capability. I also have a cheaper Hobbyking AC/DC charger for home use rather than a power supply. This limits amps to 10 which sounds big but only 2C on a 5000ma pack. At the pond I use a deep cycle marine which I have from my boat that needs the activity rather than sitting on the lift. You can also us your car/truck battery to charge with but after 6-10 charge cycles you better start your vehicle. Have used a charged 4S pack to jump and restart my car. This all works for me so anyone else give your opinions and options also.

Mic