HK Multistar high capacity, 10C batteries made for MR: Opinions from the experienced?

[Gary Seven]

Aha. Thankfully I haven't run into that issue with the icharger. Must have set it up correctly accidentally

i do recall the temp and timer safety features though. This charger has been pretty great from my perspective. No buyers remorse - and eventually I'll get I to more powerful power supply. But for now my system has worked just fine from 3S to 6S, and 450mah to 10000mah. Regardless of my confidence in the unit - I still keep a pretty close eye on it when charging.

These "iChargers" an Apple product?:friendly_wink: I wonder if they have these things here in Europe? I'm beginning to suspect my Imax B6 isn't being truthful with the mA's it puts into my LiPos. May be time for a divorce.

 

[Gary Seven]

Have you verify the tempo with a temp gun?? Mine is a 4S 8000, in a hex with all gear, gimball, landing, camera video transmitter and additional 1000 3s battery for video only. It does land warm to the touch after 13 minutes flying and landing at 13 to 13.2 loaded voltage. You must verify also that, If you are measuring the voltage after landing, they tend to go up few seconds after no load state. You should verify the ending voltage loaded.

No I haven't (yes, I indeed do have a temp gun here in my office). The batteries are warm...but NOT hot. Compared to the Zippy Flightmax I have, these Multistars run hotter, but not hot or burning to the touch. BTW, I do verify the ending voltage every time I fly.

 

[edgarmillennium]

In my case the get about 110*F just at landing. which is not bad. About the voltage, the best way to know how the ending voltage is with the IOSD or a meter connected to the balance port. Sometimes we tend to measure the voltage after few seconds of stopping the usage. I found a difference of about .5 volts, which make a huge difference.

 

[fltundra]

In my case the get about 110*F just at landing. which is not bad. About the voltage, the best way to know how the ending voltage is with the IOSD or a meter connected to the balance port. Sometimes we tend to measure the voltage after few seconds of stopping the usage. I found a difference of about .5 volts, which make a huge difference.

It's absolutely impossible to determine lipo end of discharge with voltage alone. You have to use MAH used, and voltage. Changes in temperature, internal resistance, and level of current draw, all effect lipo performance which will change as the pack ages.

 

[edgarmillennium]

Ftundra. I did not said that it will tell the exact statis of the batery. I just a guide to determine how stressed can be the battery with improper draining due to measuring the voltage wrong. My post is specific related to the temp. And for sure you know that when you lower too much the battery it tends to overheat also. So my comment goes specific to the conplain about how warn they come. Just in case the problem can be that the voltage us drooping too much whlie loaded

 

[AlienNet]

im running the Multistar 10000mah 10c on my RC Timer 650 stretched to 740mm, motors are Tarot 4006 620kv with 1355 carbon props & ztw spider 40a escs, carring a full fpv setup i am getting full 25 mins flying.

 

[RobBurn]

Thought id add my 2 cents. Bought the Multistar 4s 10000mah 10c as well. I used my onetouch charger and it stops at 8000mah. I have another charger on the way that will go the 10000. Ok i charged to 8000 and flew it for 20 minutes. I landed it and it was fairly warm, not like wow its warm but not what id like. I think after i can charge it up to the 10000 ill be able to easily get 20min and it should not get warm. I'll check back when i get my new charger and use it a few times. I typically use zippy 5000 4s 30c and get 12 min safely

enjoy

rob

 

[Gary Seven]

Thought id add my 2 cents. Bought the Multistar 4s 10000mah 10c as well. I used my onetouch charger and it stops at 8000mah. I have another charger on the way that will go the 10000. Ok i charged to 8000 and flew it for 20 minutes. I landed it and it was fairly warm, not like wow its warm but not what id like. I think after i can charge it up to the 10000 ill be able to easily get 20min and it should not get warm. I'll check back when i get my new charger and use it a few times. I typically use zippy 5000 4s 30c and get 12 min safely

Thanks for the input. I don't understand that remark, "it stops at 8000 mah." Your charger should be able to put in as many mA as your battery requires. Is your charger programmable? There must be some sort of "cut off" set that won't let it charge past a certain value. I'd like for others in the know to chime in here,

My Multistar 4000 mAh, 3S, 10C runs a bit different than my Zippy Flightmax 4000 mAh, 3S, 20C. It gets much warmer (comparatively speaking) after a complete discharge than the Zippy (not hot mind you, just warmer), and tends to really drop off quickly when "sagging." I get about 15 minutes solid fly time with it.

The Zippy in comparison tends to be much cooler after a complete discharge. It also tends to behave better at the end of the run when voltage sagging becomes readily apparent. It seems I'm getting 17-19 min run time on this battery, but I'm not sure this is a valid statement as the batteries and not really broken in yet. All in all I'm so far quite happy with both batteries, especially the Multistar considering how much smaller it is compared to the Zippy.

 

[AlienNet]

Thanks for the input. I don't understand that remark, "it stops at 8000 mah." Your charger should be able to put in as many mA as your battery requires. Is your charger programmable? There must be some sort of "cut off" set that won't let it charge past a certain value. I'd like for others in the know to chime in here,

My Multistar 4000 mAh, 3S, 10C runs a bit different than my Zippy Flightmax 4000 mAh, 3S, 20C. It gets much warmer (comparatively speaking) after a complete discharge than the Zippy (not hot mind you, just warmer), and tends to really drop off quickly when "sagging." I get about 15 minutes solid fly time with it.

The Zippy in comparison tends to be much cooler after a complete discharge. It also tends to behave better at the end of the run when voltage sagging becomes readily apparent. It seems I'm getting 17-19 min run time on this battery, but I'm not sure this is a valid statement as the batteries and not really broken in yet. All in all I'm so far quite happy with both batteries, especially the Multistar considering how much smaller it is compared to the Zippy.

i charge my 10000 mah 4s lipo at 5 amp with no problem, may take a while longer but i can live with that,

 

[RobBurn]

Thanks for the input. I don't understand that remark, "it stops at 8000 mah." Your charger should be able to put in as many mA as your battery requires. Is your charger programmable? There must be some sort of "cut off" set that won't let it charge past a certain value. I'd like for others in the know to chime in here,

Yes its a restriction of the charger i have and i dont see a work around. its a 1st gen onetouch. I needed to get a multi charger any way, i was dumb and getting rid of so rc car stuff i sold off my 4 port charger.

I didnt mention in the last oost but going from a 5000 to the 10000 batt messsed up a few things, one i had to adjust to to center cg and also my two batt straps were not useable, to short. I actually have a velcro system on the batt to top plate of f550 but the straps are an extra precaution. The 10000 is BIG. The motors after 20 minutes was barely warm.

I should also say i live in a hot hot area in the summer and its still 90 right now during the day, it was 90 when i flew this batt. Its suppose to be in the 70's this coming week.

gary it would be helpful if you had you mr specs in your sig or something as your flight times do t correlate to anything in my mind as what weight are you carrying etc.

your right the zippy is very stable and i could run my 5000 out to 14 minutes or more it would get pretty warm, i bring it back a couple minutes from that so i have a decent safety margin.

My mr is 2250g with zippy 5000 4s , which weighs in at 550g. So with 4s multistar 10000 at 800g its at its max payload of 2400g

 

[cootertwo]

I bought 4 when they first came out. 2, 4000 4s 14.8 and 2, 4000 3s 11.1 NOT very impressed with either. Will not try again.

 

[Mactadpole]

max discharge amperage for a 6S 10,000mah 10C pack should be 100 amps total. If you're running two batteries in parallel then they split the load and the max for the dual battery system would be 200 amps. That's maximum so if you're hovering at 50% throttle then you should be pulling 100 amps hovering to keep yourself from exceeding the max discharge amps level at max throttle.

these aren't necessarily going to be a great option for anyone that is out there flying FPV at max throttle around race courses or wide open expanses of land unless the packs are sized accordingly.

if you're hovering around, doing aerial media type stuff then you'll be more likely to find these packs useful.

also, for those of you with more advanced battery chargers, make sure there isn't a MAX MAH IN limit set in the charger that would prevent it from fully charging the packs due to a max mah limit being hit before the battery is fully charged.

Hoping I can get some input from Bart or any of you other battery pro's.

I just bought 2x Multistar 4S 8000mah 10C packs. If I follow what Bart says above, am I correct that max discharge amperage should be 80 amps? And if I am running two of these in parallel I should be good to 160 amps? My X8 copter is about 3.3kg when fully loaded (includes batteries) and hovers around 43 amps. At full throttle it pushes 100 amps but I don't ever do this except to see what it is. I flew these batteries today at 70F temp and got 17.5 minutes of flight time landing at 14.2 volts under load. Awesome! The batteries were mildly warm. What is throwing me off is that when I charged them (8 amps max in) they ended up taking 7458 mah total in one and 7519 in the other. Way more than I expected. Thoughts? Is the rated 8000mah just off? I thought I was being super conservative landing at 14.2 volts.

Now, my main question is that I am getting ready to leave for the tropics where I will be flying waypoint missions for forest mapping and curious if these will still do ok when I am flying at 85-95F temps? I sure do like the 3.5 minutes extra flight time I get over the Zippy compact 4S 6200mah batteries I've been using.

Thanks,

Shawn

 

[Bartman]

Shawn,

Those numbers look right but at those loads I wouldn't expect them to be warm. Using a min voltage of 3.3 volts per cell, with your 4 cell pack that would be 13.2 and you were 1 amp over that when you landed. If you're doing waypoint flights with the Pixhawk and have a high speed set between waypoints it may be pulling pretty close to max when transiting waypoints.

I don't know much about those packs so I can't really question the ratings with any authority.

My only suggestion would be to fly them four or five more times and see if they show any signs of puffing. That and use your charger to measure internal resistance if possible. Actually, check the IR first and then if the numbers are in the .2 to .3 range go ahead and fly them to see if they're puffing at all. If they are then I'd be suspicious of the max discharge C ratings.

Hope that helps.

 

[Mactadpole]

Shawn,

Those numbers look right but at those loads I wouldn't expect them to be warm. Using a min voltage of 3.3 volts per cell, with your 4 cell pack that would be 13.2 and you were 1 amp over that when you landed. If you're doing waypoint flights with the Pixhawk and have a high speed set between waypoints it may be pulling pretty close to max when transiting waypoints.

I don't know much about those packs so I can't really question the ratings with any authority.

My only suggestion would be to fly them four or five more times and see if they show any signs of puffing. That and use your charger to measure internal resistance if possible. Actually, check the IR first and then if the numbers are in the .2 to .3 range go ahead and fly them to see if they're puffing at all. If they are then I'd be suspicious of the max discharge C ratings.

Hope that helps.

Thanks, Bart. I think you meant one volt over acceptable min on landing. I don't think I was getting anywhere near the max amps of 160 with two batteries in parallel during flight.

I just did another flight with my watts up meter on it and did discover that my frsky FLVSS volt meter is not accurate under load at lower voltages - watts up meter was reading 13.9V for both cells in parallel and the FLVSS was reading 14.2V for just a single battery. Could the difference simply be that the FLVSS was connected to a balance port? It did also give me a chance to calibrate my Volts and Amps on the Pixhawk power module finally. Something I should have done long ago. I brought my surface thermometer and the Multistar's were 29-30 Celcius (84-86F) after 17 minute flight compared to not-flown batteries at 20-21C (68-70F). I flew a waypoint mission and then just flew around messing with Pixhawk battery calibration. I even did a few 3/4+ throttle climbs and the max amperage recorded was 86 amps. So no where near the max.

Still curious on the temps concern I have? I normally fly the Zippy 4S 6200mah batteries and they are a little warm when done flying too but I need to compare.

 

[Mactadpole]

BTW - Both of the Multistar 4S 8000mah batteries just took a more acceptable input of ~6550mah. I'm cheap, not able to get IR from my chargers.

 

[Gary Seven]

I see this thread is active again and as such would like to add an "update" (ie, some thoughts) on these Multistar batteries. Would appreciate input from those that I think have tried them, especially @cootertwo, @Motopreserve, @Bartman, @PeteDee, @kloner, @Carapau (not sure if the last three listed have used them or not), or anyone else for that matter.

I have flown both the Multistars and my Zippy Flightmax's at least 25 times (each). What I'm really starting to notice as of late is the Multistars sort of "misbehaving" towards the end of my flight. Voltage sag appears to be getting worse in that my little on-board alarm has been going off sooner and sooner with even moderate throttle input. What I mean by that is this: Before I used to set my alarm at either 3.6 or sometimes 3.5V and enjoy a flight of about 15-17 min before the thing started chirping away. Now the alarm starts to go off (depending upon load of course) at around 10 min flight time. If I stop flying and later go to recharge, I notice I'm only putting back in about 2800-2900 mA (maybe 3000). When they were newer, I would put back about 3200-3600 mA after the alarm told me to land.

So what I've been doing now is lowering my alarm set point to 3.4V, and this usually gives me back around 14-15 min flight time before it goes off (again, depending how I load it during flight). A recharge will put back in anywhere from 3200-3800 mA. However, just the other day the alarm starting chirping away only after about 8 min flight time, so I landed and recharged after battery cooldown. It only took about 2500 mA so this tells me I probably have a cell (in my 3S pack) going bad. I currently have no way to test IR as I only have a crappy Imax B6 charger, but I am planing on buying an iCharger 406Duo after the 1st of the year.

I've had no such issues with my Flightmax batteries. Just food for thought, folks.

 

[Bartman]

sorry guys but it's impossible to say if the batteries are at fault without having internal resistance numbers.
you're familiar but it goes like this, the batteries are warm but are they puffing? the flights are shorter, are they warming up when they're being charged? the batteries are puffing, are you running them at or beyond their limit (exceeding rated discharge amps)? there are symptoms but they all point to either ratings being exceeded (it looks like you're good there Shawn) or the batteries having higher than normal internal resistances.

when the packs develop resistance inside the cells the electricity flowing through them will cause heat to be created, just like a lightbulb. when you're charging, the resistance will generate heat just like when discharging. so if resistance has formed inside the packs, they will warm when being used, they'll warm when being charged, they won't take as much of a charge, and they won't last as long when you're flying them. lightbulbs get hot, you want your packs to be more like batteries and less like lightbulbs.

Shawn, it's possible the heat is ok....if flight times stay the same, if the packs don't puff, if they don't keep getting warmer and warmer as they are charged/discharged then the heat is probably an acceptable condition.

Gary, are you using the battery monitors from HobbyKing with the digital readout or just the alarms? the digital readouts will tell you the voltage of each cell and yes, one bad cell will cause those monitors to chirp.

 

[Mactadpole]

Good to know Gary, thanks for chiming in. Thanks too Bart. I will keep updating this thread. BTW- I now realize part of my APM/Pixhawk volt and current readings may have to do with the fact that I am exceeding the 60A rating for the APM power module. Just ordered a 90A one. That is a serious oversight on my part.

A little background here. I am delivering this copter to a non-profit organization that runs several reserves in the Choco forest region of Ecuador so they can monitor illegal logging on their properties and adjacent properties. They are on a very tight budget and I am actually donating a lot of stuff to them. I am trying to find inexpensive quality components for them to use. I know those two words don't go together but it is what it is. FYI - I ordered an X100 AC/DC charger from HK and it crapped out after 6-7 charging sessions. Any suggestions on an inexpensive AC/DC charger? I want to get them two just in case one dies. Which it will. I might just stick with the Zippy compact 4S 6200mah for now since I know they are trustworthy, for the most part. The addition 3+ minutes of flight time from these Multistars sure is nice though. The problem is nothing can be shipped (corrupt customs) and has to be hand delivered.

 

[Bartman]

Shawn,

The best you can do when trying to save money on a charger, IMHO, is to save by using the computer server power supplies (available on eBay) while still buying a high quality brand name charger. Here's a pic of my set-up using two Dell power supplies in series to get 24 volts but with an iCharger 206B. Probably not what you wanted to hear but a low quality charger can destroy your expensive batteries and maybe cause a LiPo fire. I've heard of other HobbyKing chargers lasting only a few charge cycles. The iCharger 306B is about $160 and with the two power supplies it's around $180 depending on what you pay for the power supplies.
Probably not the reply you were looking for, sorry!
View attachment 22063

 

[Mactadpole]

Hey Bart,

I use those supplies for my cheap chargers now and I should just upgrade to a few of these more quality chargers for myself.

I really wanted to find some decent self-contained AC/DC chargers for the organization to take to them. At their two field stations all they will have access to is two truck batteries hooked up to a solar charger with inverter. Their other option is to walk 45 minutes into town and plug their charger(s) in at a local internet/phone cafe or tienda to charge the batteries. I'm try to find something that is small and self-contained to just make things easier. I might just go with two of the iMAX B680AC (AC/DC) and they will just have to deal with a slower charger cycle. One of these was my original charger and it has worked flawlessly for many years, even though its a slower charger.

Sorry for derailing the thread a little.