[NSRCA-discussion] 10s LiPo Charger Recommendation
Vicente Bortone
vincebrc at gmail.com
Fri Oct 9 07:38:21 AKDT 2015
Dave,
Thanks for the detailed analysis. I agree 100%.
Vicente "Vince" Bortone
On Friday, October 9, 2015, Dave Lockhart via NSRCA-discussion <
nsrca-discussion at lists.nsrca.org> wrote:
> Some random comments to a long thread –
>
>
>
> I believe a number of commercial lipo applications specifically limit
> “full charge” voltage to less than 4.2 volts, and limit “discharged”
> voltage to something higher than 3.5 volts. Operating the lipo in the
> middle of the voltage range increases longevity and reduces the odds of
> failure. I’ve asked a number of “experts” if RC applications would be
> better served by operating between 4.2 and 3.75 (typical), or 4.15 and 3.7,
> or 4.3 and 3.8……never received a clear answer. Hyperion is another lipo
> supplier that has been advertising 4.35 volt capability for several months
> now on their latest generation of lipo cell.
>
>
>
> ThunderPower might know the most about charging lipos for RC use, since
> they have been doing it as long as anyone? The earliest viable packs for
> pattern use were various “4p” configurations. Early lipo cells could not
> support high discharge rates, so putting cells in parallel was the only
> option to support high discharge rates - even then, the first pattern packs
> had a 6C BURST rating. ThunderPower moved away from the “4p”
> configurations as soon as it was viable to do so.
>
>
>
> I don’t personally like the idea of parallel charging…simply because I
> want to see the voltage of each cell….and mah to recharge each pack…which
> is also part of the reason why I run the TP5s5000 packs instead of the
> 5s5400s (which are actually 10 2700s in 5s2p configuration). Tracking the
> voltage at the end of a flight vs the mah needed to recharge tells you
> quite a bit about the actual capacity of the cells.
>
>
>
> Several years ago, I tried 2C charging (packs were rated for 5C
> charging). I have not done it since, as I believe 2C charging reduced the
> lifecycles of the packs by about 30%. I’ll also note that with smaller
> packs used for indoor flying, 3C charging seems to have negligible impact
> on lifecycle. When time allows, I charge my pattern packs at 3.5
> amps…figuring if 1C charging is better than 2C charging…. 0.7C charging
> might be better yet.
>
>
>
> The number of good chargers out there is far greater than in the past….the
> weak point with all of the chargers / charging systems is the balance
> connectors….they wear out, get dirty, etc, causing false readings in the
> chargers.
>
>
>
> Solid power supplies are much cheaper than in the past. If I needed a new
> power supply, I’d go for a pair of the 75 amp HP server power supplies
> (contact RVP….he has them cheap with leads attached)….lots of charging
> power, compact, and easy to put a pair in series for 1800 watts of power
> (more than a 15 amp household circuit)…..enough to comfortably power a wide
> range of charging schemes. I currently have 2 different charger boxes….one
> has a pair of IOTA 55 amp supplies in series running a pair of TP820s, and
> the newer charger box has a pair of HP 47 amp supplies (much lighter) in
> series running a pair of TP820s. Both charger boxes have more than enough
> overhead (chargers and supplies) to charge 4 5s5000s at 2C, should I need
> to charge rapidly. Wiring to and from the power supplies becomes
> increasingly critical as the wattage goes up….at a 1000 watts, plenty of
> computer monitor power leads (intended for less than 100 watts) will get
> hot. Power leads intended for the power supplies have a lot more capacity.
>
>
>
> Regards,
>
>
>
> Dave
>
>
>
>
>
>
>
>
>
>
>
>
>
> *From:* NSRCA-discussion [mailto:nsrca-discussion-bounces at lists.nsrca.org
> <javascript:_e(%7B%7D,'cvml','nsrca-discussion-bounces at lists.nsrca.org');>]
> *On Behalf Of *Peter Vogel via NSRCA-discussion
> *Sent:* Friday, October 09, 2015 12:40 AM
> *To:* Robert L. Beaubien <rob at koolsoft.com
> <javascript:_e(%7B%7D,'cvml','rob at koolsoft.com');>>; NSRCA List <
> nsrca-discussion at lists.nsrca.org
> <javascript:_e(%7B%7D,'cvml','nsrca-discussion at lists.nsrca.org');>>
> *Subject:* Re: [NSRCA-discussion] FW: 10s LiPo Charger Recommendation
>
>
>
> If you go to 4.35v/cell your 10s pack voltage is in excess of that allowed
> by the rules by 1.5v
>
>
>
> Peter+
>
> Sent from Outlook <http://aka.ms/Ox5hz3>
>
>
>
>
>
> On Thu, Oct 8, 2015 at 8:46 PM -0700, "Robert L. Beaubien via
> NSRCA-discussion" <nsrca-discussion at lists.nsrca.org
> <javascript:_e(%7B%7D,'cvml','nsrca-discussion at lists.nsrca.org');>> wrote:
>
> Ed,
>
>
>
> I have talked with a number of battery manufacturers and while their
> batteries support as high as 9c charge rates, every one recommend NOT
> charging any higher than 2c charging rates. Anything higher, while
> tolerated by the battery, would definitely shorten the life of the
> battery. The best benefit of parallel charging is not using a high C
> charge rate, but that you are charging multiple batteries at the same
> time. It reduces the need to have to charge fast (at least for me).
>
>
>
> Also, I’m looking forward to the coming HV Lipo packs where you charge the
> cells to 4.35v/cell instead of 4.2v/cell. Turnigy (
> http://hobbyking.com/hobbyking/store/__1415__85__Batteries_Accessories-Turnigy_BOLT_LiHV_.html
> ) has them already and GiantPower is close to releasing their packs with
> these cells. They should give a nice boost in performance for a similar
> weight battery.
>
>
>
> - Robert Beaubien
>
> - Sr. Software Architect
>
> - Kool Software LLC
>
>
>
> “Dear Algebra, Please stop asking us to find your X. She's never coming
> back and don't ask Y.”
>
>
>
> *From:* Ed Alt [mailto:ed_alt at hotmail.com
> <javascript:_e(%7B%7D,'cvml','ed_alt at hotmail.com');>]
> *Sent:* Thursday, October 8, 2015 6:10 PM
> *To:* Robert L. Beaubien <rob at koolsoft.com
> <javascript:_e(%7B%7D,'cvml','rob at koolsoft.com');>>; NSRCA List <
> nsrca-discussion at lists.nsrca.org
> <javascript:_e(%7B%7D,'cvml','nsrca-discussion at lists.nsrca.org');>>
> *Subject:* RE: [NSRCA-discussion] FW: 10s LiPo Charger Recommendation
>
>
>
> Thanks for the response Robert. I can definitely see doing this at low to
> moderate C rates as with your example. I might run a test to see what the
> voltage difference is between parallel battery sets at higher C rates,
> maybe around 4 to 5C. The thing that I have in mind is, that depending on
> how things are connected, what the resulting resistance is in the path to
> the 2nd, 3rd, 4th parallel pack and so forth, and what the charging current
> is, then you might see a problem with some packs charging more than
> others. If you keep the the wiring lengths the same from the charger to
> each pack, then there should not be an issue. An example might be
> something resembling a bicycle wheel, with the charger at the hub of the
> wheel, and battery packs distributed around the hub with one pack per
> "spoke".
>
>
>
> However, if you instead choose to wire it to resemble a train track, with
> a relatively simple charger at one end of the track and battery packs
> strung out like railroad ties along the rails, then a issue may exist at
> some point. The reason is that the higher the charging current value is,
> the more voltage drop there will be along the wiring from one pack to the
> next, skewing the results from one pack to the next. Now depending on how
> the charger algorithm is designed, that may not matter. For example, an
> improved charger design could pulse the charging current on and off, and
> during each brief "off" time, take no load voltage readings that would be
> virtually unaffected by the extra resistance in the wiring to the 2nd
> pack. More sophisticated methods could be applied that you might expect
> could vary from one brand or model charger to the next, but this should
> illustrate the point that results may vary depending on a number of
> factors.
>
>
>
> Careful monitoring and not pushing C rates really high as you have done
> will certainly tell you enough. If someone wants to really push the limits
> without incurring too much risk, my suggestion is that they determine the
> wiring method based on an understanding of how the charging system will be
> able to measure what is happening. If your charging system can monitor
> individual parallel pack voltages and suss out how those separate readings
> relate to the state of the group of batteries, you get easily push C rates
> higher without much regard to the wiring scheme (hub and spoke vs RR track,
> if you will). If your charging system lacks independent battery voltage
> sensors, but is known to have an algorithm that can work around that, also
> good. Personally, I wouldn't go against any manufacturer's specific
> recommendation to avoid parallel charging with their product.
>
>
>
> Ed
>
>
> ------------------------------
>
> To: nsrca-discussion at lists.nsrca.org
> <javascript:_e(%7B%7D,'cvml','nsrca-discussion at lists.nsrca.org');>
> Date: Thu, 8 Oct 2015 20:39:19 +0000
> Subject: Re: [NSRCA-discussion] FW: 10s LiPo Charger Recommendation
> From: nsrca-discussion at lists.nsrca.org
> <javascript:_e(%7B%7D,'cvml','nsrca-discussion at lists.nsrca.org');>.
>
> I have done a lot of parallel charging this year. I was originally worried
> about cell balance charging this way when I started so I closely monitored
> the cell voltages before and after charging. I’m typically charging 1800
> 75c 4s packs, 4 at a time at 14amps (2c per pack). Every check of the
> cells after charging shows they balance very well and are within .02 volts
> each and I have about 100 cycles on each pack this way. I use the RMRC
> ParaBoard (
> http://www.readymaderc.com/store/index.php?main_page=product_info&cPath=84_387&products_id=2984
> ). Certainly not the 10s packs used in pattern, but charging them as 5s
> packs would work nicely using this system.
>
>
>
> - Robert Beaubien
>
> - Sr. Software Architect
>
> - Kool Software LLC
>
>
>
> “Dear Algebra, Please stop asking us to find your X. She's never coming
> back and don't ask Y.”
>
>
>
> *From:* NSRCA-discussion [mailto:nsrca-discussion-bounces at lists.nsrca.org
> <javascript:_e(%7B%7D,'cvml','nsrca-discussion-bounces at lists.nsrca.org');>]
> *On Behalf Of *Ed Alt via NSRCA-discussion
> *Sent:* Thursday, October 8, 2015 12:54 PM
> *To:* Keith Hoard <klhoard at outlook.com
> <javascript:_e(%7B%7D,'cvml','klhoard at outlook.com');>>; General pattern
> discussion <nsrca-discussion at lists.nsrca.org
> <javascript:_e(%7B%7D,'cvml','nsrca-discussion at lists.nsrca.org');>>
> *Subject:* Re: [NSRCA-discussion] FW: 10s LiPo Charger Recommendation
>
>
>
> Although I haven't done parallel charging, it seems like it would be ok
> within certain limits. The main limiting factor might be the path
> resistance between parallel cells, but really only in the case of high C
> rate charging. That's a theory anyway. What has your experience been at
> high C rates? Does it seem to make much difference?
>
>
>
> Ed
>
>
> On Oct 8, 2015, at 3:09 PM, Keith Hoard via NSRCA-discussion <
> nsrca-discussion at lists.nsrca.org
> <javascript:_e(%7B%7D,'cvml','nsrca-discussion at lists.nsrca.org');>> wrote:
>
>
>
> I have found that the loudest detractors of parallel charging have no
> experience parallel charging. When I ask them to point to an incident
> where parallel charging caused a problem, the answer is always “Well, I
> read on the internet . . . “
>
> .
>
> I do a lot of parallel charging, and have no problem “putting the spurs”
> to my packs during charge if I’m ready to get in the air. To dispel one
> myth right now, a good quality charger **WILL** detect a bad cell during
> parallel charging.
>
>
>
> (steps up on soapbox) . . .
>
>
>
> **I HAVE ACTUALLY SEEN IT WITH MY OWN EYES AND CONFIRMED IT WITH FURTHER
> TESTS**
>
> **PLEASE DON’T KEEP REFERRING ME BACK TO “THE INTERNET”**
>
> **IF YOU GIVE ME ONE OF YOUR CRAPPY PUFFED UP PACKS, I’LL PUT IT ON WITH
> ONE OF MY GOOD PACKS AND SHOW YOU**
>
>
>
> OK, with that statement out of the way . . . . (steps down off soapbox) .
> . . .
>
>
>
> The only time that bad cell **MAY** be masked is if you are parallel
> charging 4 or 6 packs. In practical use, you would only be parallel
> charging that many batteries on very rare occasions, perhaps once per
> season. Besides, most chargers out there don’t have enough ass to charge 6
> pattern packs in parallel and be done before sundown anyway. However, you
> should not be relying on your charger as the only point in your routine to
> detect bad cells.
>
>
>
> In my experience, folks with bad cells and puffy packs are doing a myriad
> of other no-no’s. The worst is taking their batteries home on a full
> charge and letting them sit all week or all winter. My soapbox finally
> broke down on that one and now I just smile and say “That’s too bad” and
> keep walking down the flight line.
>
>
>
> Ironically, the “straw that broke the camel’s back” for me was an H1B
> German Engineer who flies at our field asked me how I keep my packs from
> puffing up. Every time I said “storage charge at the end of the day”, he
> would reply “I don’t do that.” Then I said, “Yes, that’s why your batteries
> are all puffy and trashed.” To which he replied “Yes, I charge my
> batteries to 100% before taking them home.” . . . <Sigh> . . .
>
>
>
> I now understand how VW got busted.
>
>
>
> *From:* NSRCA-discussion [mailto:nsrca-discussion-bounces at lists.nsrca.org
> <javascript:_e(%7B%7D,'cvml','nsrca-discussion-bounces at lists.nsrca.org');>]
> *On Behalf Of *Vicente Bortone via NSRCA-discussion
> *Sent:* Thursday, October 8, 2015 13:16
> *To:* James Hiller <jnhiller at earthlink.net
> <javascript:_e(%7B%7D,'cvml','jnhiller at earthlink.net');>>; General
> pattern discussion <nsrca-discussion at lists.nsrca.org
> <javascript:_e(%7B%7D,'cvml','nsrca-discussion at lists.nsrca.org');>>
> *Subject:* Re: [NSRCA-discussion] 10s LiPo Charger Recommendation
>
>
>
> For some reason TP does not recommend parallel charging. Probably because
> it is difficult to keep track of each cell and values are averaged. Is
> this really an important factor? At this point I just following
> instructions. This factor could be important to decide what charger to buy.
>
>
>
> Vicente "Vince" Bortone
>
> On Thursday, October 8, 2015, James Hiller via NSRCA-discussion <
> nsrca-discussion at lists.nsrca.org
> <javascript:_e(%7B%7D,'cvml','nsrca-discussion at lists.nsrca.org');>> wrote:
>
> Plug & play charge box from Progressive RC (see photo).
> Parallel charging 5 flight packs in one session while having a couple cold
> ones!
> Jim
>
>
> -----Original Message-----
> From: NSRCA-discussion [mailto:nsrca-discussion-bounces at lists.nsrca.org
> <javascript:_e(%7B%7D,'cvml','nsrca-discussion-bounces at lists.nsrca.org');>]
> On Behalf Of Dr. Michael Harrison, DDS via NSRCA-discussion
> Sent: Thursday, October 08, 2015 9:46 AM
> To: 'Earl Haury'; 'General pattern discussion'
> Subject: Re: [NSRCA-discussion] 10s LiPo Charger Recommendation
>
> lol
>
> -----Original Message-----
> From: NSRCA-discussion [mailto:nsrca-discussion-bounces at lists.nsrca.org
> <javascript:_e(%7B%7D,'cvml','nsrca-discussion-bounces at lists.nsrca.org');>]
> On Behalf Of Earl Haury via NSRCA-discussion
> Sent: Thursday, October 08, 2015 8:26 AM
> To: Budd Engineering; General pattern discussion
> Subject: Re: [NSRCA-discussion] 10s LiPo Charger Recommendation
>
> Jerry
>
> Hard to beat the iChargers. The CellPros taught me that a fuse between the
> pack & charger is a good investment! No issues with 3010b iChargers (about
> 3000 charges over 5 years or so). They will report cell IR / voltage and
> charge a 10S pack at 2C with a 24v supply without breaking a sweat. The
> newer 4010 can handle 2x10S and displays data from both packs
> simultaneously. They don't meet your criteria of charging through the
> balance leads, but haven't really found that to an issue as the balancing
> system works fine. Can't really comment on service, haven't needed any
> (that should jinx me).
>
> Earl
>
> -----Original Message-----
> From: Budd Engineering via NSRCA-discussion
> Sent: Thursday, October 08, 2015 4:59 AM
> To: List NSRCA-list
> Subject: [NSRCA-discussion] 10s LiPo Charger Recommendation
>
> Hi all, I m in need of some advice/suggestions for a new LiPo charger for
> 10s packs.
>
> For the past several years I ve used CellPro-10S chargers with good
> results.
> However recently one of my CellPro-10s' emitted the dreaded magic smoke
> when I connected a 10s pack for charging. This also happened at the Nats 3
> years ago, fortunately Mike M. from F3AU was there with inventory and I was
> able to purchase a replacement charger and press on. However, after having
> a second one give up the ghost a few weeks ago (and after not many charge
> cycles - I don t fly very much), I m interested in exploring other options.
>
>
> To try to add some focus to this here s my search constraints:
>
> 1. It must be able to charge each cell individually through the balance
> connector, and give me a relative readout of each cell s condition compared
> to the other 9 cells.
>
> 2. I m not interested in chargers that have separate balancers from the
> charger (e.g. like the TP1010C).
>
> 3. Reliability and value are important, as is ease of use.
>
> 4. Cost no more than a replacement CellPro 10XP (<$180), unless a single
> charger can charge two 10s packs simultaneously, then I d consider spending
> a bit more.
>
> 5. Customer service matters, if I can buy it through F3A Unlimited, that
> would be a PLUS.
>
>
> With this in mind does anyone have a suggestion for what chargers I should
> consider?
>
>
> I don t get out much these days so it s difficult to see what everyone s
> using that works well. So I really do appreciate everyone s help with
> this.
>
> Thx, Jerry
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>
> --
> Vicente "Vince" Bortone
>
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--
Vicente "Vince" Bortone
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