A 48V 10.4 Ah battery mount with no connectors.

A 48V 10.4 Ah battery mount.

I used 2 pieces of 1/2" plywood and utlized the water bottle screws and super heavy zip ties to hold everything in place.

There are 2 series strings of 6s 5,200 HK battteries.

http://www.hobbyking.com/hobbyking/...apacity_6S_5200mAh_Multi_Rotor_Lipo_Pack.html

There are access points to measure the Voltage of each battery and each cell,

The blue tape is covering the series connection point.

I just made a 1 mile ride at 20 mph,

The cells were charged to about 4.15 V average.

(The Walmart Boosters gave me 1,800 miles)

I can feel the difference.

Isn't that a 44 or 45v 5.2 ah battery? 13s is 48v.

I bet you feel the difference,, a hell of a lot less sag under load I bet.

Yes, 5.2Ah. Dunno where 1.4Ah came from?

I prefer these because they don't need protection using extra material(s) -

http://www.hobbyking.com/hobbyking/store/__58976__Turnigy_5000mAh_4S1P_14_8v_20C_Hardcase_Pack_AR_Warehouse_.html

Good price now too - $23ea. (might need to login to see that price?)

3 of those in series (4mm bullets easier to series wire too) makes 12S. Sure, a little less capacity (barely) but you can buy 3qty shipped for $80-$90.

How much did those 2qty 6S MultiStar's cost, shipped?

I think he has 4 of the Multistars. Wired 12S 2P, and meant to write 10.4Ah

dogman dan said:

Isn't that a 44 or 45v 5.2 ah battery? 13s is 48v.

I bet you feel the difference,, a hell of a lot less sag under load I bet.

Click to expand...

I bet you feel the difference,, a hell of a lot less sag under load I bet. Yes!

Just went 6 miles 49.7 > 48.6V

12s 4.15 x12 = 49.8V / 2 = 24.9V

The spec: Configuration: 6S1P / 22.2V / 6Cell. However 22.2 / 6 = 3.8 V

Would you charge to only 3.8 V? I would not.

Gregory said:

I think he has 4 of the Multistars. Wired 12S 2P, and meant to write 10.4Ah

Click to expand...

Thanks for the correction. Yes, 10.4 Ah

Gregory said:

I think he has 4 of the Multistars. Wired 12S 2P, and meant to write 10.4Ah

Click to expand...

Thanks Greg. All I could see in the photo was 2qty 6S packs.

My preference still stands for the hardcase packs. Easier to series wire and better pouch protection. Also a little better C rate, IMO...

Just received;
Tucson, AZ 85712
United States
Transaction ID
7FY39004FH4261057
Seller info
hexTronik Limited
support@unitedhobbies.com
Your purchase
912700002-0 (Qty 6)
Multistar High Capacity 4S 5200mAh Multi-Rotor Lipo Pack (AR Warehouse)
$125.94
Item #66476
Shipping$12.28
Tax$0.00
Purchase total$138.22
Fee$0.00
Total$138.22

12S/10.400 mAh for less than $140 :lol:

For a budget assist build I'm doing;

Q100CST-............................$140
Batteries-............................$140
Controller-............................$40
Truvativ Chainring MTB 48t-.......$30
Small frame bag-....................$10
Spokes-................................$20
Sidestand-.............................$10
Tektro Ebike levers-.................$10
Used GT I Drive MTB................$350(Like new. Came with new Forte Flat resistant tires and tubes, Krypto loc, seatbag



Total of $750(not including charger, rim and connectors and wires which I had)

motomech said:

Just received;
Tucson, AZ 85712
United States
Transaction ID
7FY39004FH4261057
Seller info
hexTronik Limited
support@unitedhobbies.com
Your purchase
912700002-0 (Qty 6)
Multistar High Capacity 4S 5200mAh Multi-Rotor Lipo Pack (AR Warehouse)
$125.94
Item #66476
Shipping$12.28
Tax$0.00
Purchase total$138.22
Fee$0.00
Total$138.22

12S/10.400 mAh for less than $140 :lol:

Click to expand...

Same deal. What a winner!

Are you going to connect them as I did?

Ykick said:

Gregory said:

I think he has 4 of the Multistars. Wired 12S 2P, and meant to write 10.4Ah

Click to expand...

Thanks Greg. All I could see in the photo was 2qty 6S packs.

My preference still stands for the hardcase packs. Easier to series wire and better pouch protection. Also a little better C rate, IMO...

Click to expand...

The plywood "sandwich" offers a lot of protection.

If the place the batteries front to back you can use the short leads provided and 8-32 machine screws to connect them in series (or parallel).

I connected the first group of three in series using 3.5 m/m bullets in the middle and 4 m/m bullets on the ends;



Then I parallel using standard 14awg HK adaptors(luv low-powered systems for easy wiring)



Since I use Battery Medics to ck/bal., I need to splice the bal. extensions so I only need 4 BM's, instead of 6.
3 + 3 to 6 are available, but I need 4 + 2 to 6, so I need to make my own;

View attachment 3

My first try didn't work too well. I started @ the red wire and forgot that electricity "flows backwards" and the wire started to smoke. One thing I have learned over the years is to be ready for these things and I pulled it apart before the wires melted. I will try again today, starting @ the black wire;



One set of three bricks will go in one side of the sm. frame bag and the other set in the other;

Since the power wires are right there, I decided to put a Wattmeter in the clear pouch on top of the frame bag.
I want to keep it simple, so I ordered one of these;

https://www.amazon.com/gp/product/B017FSED9I/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

I researched many types, but only this one has an on/off for the back light. That way I can just leave it on all the time as the LCD screen doesn't draw much current. Also, since my controller is only a 17 Amp model, I won't need to use the external shunt.

You guys having fun ? Just don't over discharge. Leave some room before lvc or 3.5v any one cell.

999zip999 said:

You guys having fun ? Just don't over discharge. Leave some room before lvc or 3.5v any one cell.

Click to expand...

My LVC is 3.5V average.

My rides never get me close to LVC even after 1,800 miles with the weak Walmart Boosters.

My estimate that after a days ride, I will be at 3.75 or higher.

I now have a one plug charger connection.

Set Voltage for 49.8V at 3 A max and walk away. Easy peasy.

999zip999 said:

You guys having fun ? Just don't over discharge. Leave some room before lvc or 3.5v any one cell.

Click to expand...

You guys having fun ?

Click to expand...

Almost as much fun as playing with fire.

Just don't over discharge. Leave some room before lvc or 3.5v any one cell.

Click to expand...

See the controllers listed in my sig.?
Hard and fast LVC @ 42 Volts (tested)
I wouldn't ride with Lipo if I didn't trust my contriller's LVC

Sorry I got confused by the typo,, I thought you had a two pack setup. 12s 10 ah,, or in this case 10.4,, is a great setup for a new lipo user. Big enough to run a pretty powerful controller and have some good range, yet small enough to be easy to carry. Not too hard to charge the hard way either,, with a cheap 6s charger.

dogman dan said:

Sorry I got confused by the typo,, I thought you had a two pack setup. 12s 10 ah,, or in this case 10.4,, is a great setup for a new lipo user. Big enough to run a pretty powerful controller and have some good range, yet small enough to be easy to carry. Not too hard to charge the hard way either,, with a cheap 6s charger.

Click to expand...

Easy way of charging.

I now have a one plug charger connection.

Set charging Voltage to 49.8V (3 A max) and walk away. Easy peasy.

For balance:

[youtube]wIbHLacozFo[/youtube]

Nice job Stu, simple and cost/use effective! (and motomech).
I would aim to charge them @ ~1c (~10a) . . . . Then I would walk away, but never out of sight/hearing . . .

So 6x multistars making 12s 10.4ah for ~125$
VS 6x hardcases making 12s 10ah for ~150$

Former can provide 35a
Latter can provide 70a

I'm thinking of 10x hardcase for 20s 10ah. I would like to draw 70-100a, and think they'll be up to it if taking it easy in the lower soc (might have to stop @ 3.7 resting. . .). ~250$ for a 20s 10ah 70a discharge pack (or 12s 15ah 100a discharge) beats any alternative I'm aware of. 11.4 pounds. I think my bullets are 5mm though :|

What kinda discharge current are you doing w/ the 20c Ykick?

nutspecial said:

What kinda discharge current are you doing w/ the 20c Ykick?

Click to expand...

My 16S1P 20C 5Ah Turnigy Hardcase handle 20-30A with little complaint. Anything above 25A they get a little warm but an interesting thing about 5-10A charge is that I can actually feel them cool down when charge is applied. Almost like some sort of thermal reaction where the reverse electron flow carries heat away?

However, my 30-40A eBike I use 2P configuration to double the practical C rate. That pack is now about 3 years running 5Ah Hardcase.

All this talk about labelled C rate is nice for the vendors but we’re much better off doing DC IR testing as part of a 3 step RC Lipo qualification.

1st QC test is DC IR (you can also use the AC IR function in some balance chargers but I prefer the DC loading method) Anything under 10mOhm/cell is pretty good C rate and will handle the loads I claimed above.

I do get a big grin when I receive new packs and they measure under 5mOhm/cell. I tend to quit using them (or apply for warranty replacement if new) when above 20mOhm/cell.

2nd QC test is for capacity using 3-4.2V/cell parameters and 1-2C load. Any 5Ah cell that delivers 4.8Ah or more is “good enough” for my purposes.

3rd QC step is “leakage”. Full SOC, disconnected from anything that might externally drain them and let them sit 48 hours. A small drop from 4.2V/cell to 4.17V or so is to be expected.

But any cell which drops more than that should be tested further to determine if it’s a “leaker” and continuously dropping voltage while sitting unattached to any active circuits.

btw, connecting an unprotected bulk charge and walking away and forgetting about these hydrogen fireball’s = one of the more irresponsible things a user can do with them.

For a 12S pack bulk charged to 49.8V, if you’re not paying close attention you really have no idea if 11 if cells have been charged to 4.33V but one is sitting at 2.1V, do you? Or worse, a 0V cell that shorted (when they fail they often short, btw) and now the remaining 11 cells have been pushed up to over 4.5V/cell.

nutspecial said:

Nice job Stu, simple and cost/use effective! (and motomech).
I would aim to charge them @ ~1c (~10a) . . . . Then I would walk away, but never out of sight/hearing . . .

So 6x multistars making 12s 10.4ah for ~125$
VS 6x hardcases making 12s 10ah for ~150$

Former can provide 35a
Latter can provide 70a

I'm thinking of 10x hardcase for 20s 10ah. I would like to draw 70-100a, and think they'll be up to it if taking it easy in the lower soc (might have to stop @ 3.7 resting. . .). ~250$ for a 20s 10ah 70a discharge pack (or 12s 15ah 100a discharge) beats any alternative I'm aware of. 11.4 pounds. I think my bullets are 5mm though :|

What kinda discharge current are you doing w/ the 20c Ykick?

Click to expand...

So 6x multistars making 12s 10.4ah for ~125$ Not quite. 4x making 12s 10.4ah

VS 6x hardcases making 12s 10ah for ~150$

Click to expand...

Link?

I am charging them at 1.5/10.4 C and I use a timer.

3 A max

Click to expand...

3a charge on 10.4ah is like .25c - you can charge 4 times faster.
This is a good thing because it's not good practice to charge naked lithium batteries unsupervised.

So 6x 4s multistars making 12s 10.4ah for ~125$
VS 6x 4s hardcases making 12s 10ah for ~150$

Click to expand...

I'm referring to the 5ah 4s multistars motomech covered.
The second are the 5ah 4s hardcases Ykick mentioned. They give twice the usable c rate for higher discharges.

Did you mention what the price of your 5.2ah 6s multistars?
I don't like the extra wiring to make a pack, but 4s are usually cheaper per cell.

nutspecial said:

3 A max

Click to expand...

3a charge on 10.4ah is like .25c - you can charge 4 times faster.
This is a good thing because it's not good practice to charge naked lithium batteries unsupervised.

So 6x 4s multistars making 12s 10.4ah for ~125$
VS 6x 4s hardcases making 12s 10ah for ~150$

Click to expand...

I'm referring to the 5ah 4s multistars motomech covered.
The second are the 5ah 4s hardcases Ykick mentioned. They give twice the usable c rate for higher discharges.

Did you mention what the price of your 5.2ah 6s multistars?
I don't like the extra wiring to make a pack, but 4s are usually cheaper per cell.

Click to expand...

I cannot imagine a more compact, easier to wire arrrangement than using a pair of 6s back to front..

Cheaper than these $27.99 each?

http://www.hobbyking.com/hobbyking/...apacity_6S_5200mAh_Multi_Rotor_Lipo_Pack.html

I use a 2 hour timer and that is sufficient for a full recharge.

Sometimes the 4s is super cheap. Sometimes not that much cheaper. I find the most compact pack I can get for the ah and the voltage, is 4 6s and two 2s. I run 14s, and this makes a nice compact square brick that carries nice in all kinds of bags, saddle bags, camera bags, etc. Once I go to 4s hardcase, the package gets a lot bigger and more awkward to carry. 4s and 3s makes a good 14s pack too, but it's just been my experience that the 6s packs are damn reliable. I sometimes chuck 2s early, but rarely the 6s ones. I buy in the spring,, so the packs I get are fresh, not last summers left overs.

The extra wiring of 4s doesn't bother me,, since I NEVER parallel balance plugs. If I have a bogus cell in there,, the LAST thing I want is to have it drag a second pack with it. Once I find it,, it's chucked out immediately. I go easy on the cells, so I really,, truly balance about once in 3 months.

dogman dan said:

Sometimes the 4s is super cheap. Sometimes not that much cheaper. I find the most compact pack I can get for the ah and the voltage, is 4 6s and two 2s. I run 14s, and this makes a nice compact square brick that carries nice in all kinds of bags, saddle bags, camera bags, etc. Once I go to 4s hardcase, the package gets a lot bigger and more awkward to carry. 4s and 3s makes a good 14s pack too, but it's just been my experience that the 6s packs are damn reliable. I sometimes chuck 2s early, but rarely the 6s ones. I buy in the spring,, so the packs I get are fresh, not last summers left overs.

The extra wiring of 4s doesn't bother me,, since I NEVER parallel balance plugs. If I have a bogus cell in there,, the LAST thing I want is to have it drag a second pack with it. Once I find it,, it's chucked out immediately. I go easy on the cells, so I really,, truly balance about once in 3 months.

Click to expand...

That sounds like good news for the 6s. The mount and wiring onto 8-32 screws was a snap. Short leads and soldered loops that will not fall out.

I am building my 'balance' setup. I will be using a 2 pole 6 position switch and a balance lead connector cable,

Hook it up to a multimeter and click through the 6 cells for each battery.

If I find a low cell, I can charge it with my lab PS.

I have 2- 48V strings in parallel. I assume that before taking a cell reading, I must first isolate the strings, Correct?

Yes, isolate the strings if you want to read one cell. Once you have a bad cell ruining the cell you paralleled it with,, then you can isolate and identify which cell is the worst one.

Then toss out both packs,, cuz the bad pack ruined the second one. :lol:

That only happens if you ignore the bad cell long enough. Just run them not parallel for 10 cycles or so, watch the cells, and weed out any bad pack right away, and you'll be fine.

Quality in general at HK has improved, used to be you could count on one pack in 5 being shit. But I still don't parallel at cell level out of habit. Just prefer to not have the bundle of extra wire to do it.

Get a cellog 8 or similar device for quickly checking out cell by cell voltage, you are doing it the hard way,, for sure. With my cellog 8, I can check the voltage of 28 individual cells in about 90 seconds.