# Understanding Batteries - Please help



## AmaToolBox (May 11, 2017)

Ok, doing a small project for a quad for my son, and i was considering the below setup to drive it, but my lack of knowledge on batteries is really holding me back. I know i need at last 4 @ 12v batteries to make the 48v, but what types and where to get them is becoming the tough point. Can someone provide me a recommendation as to the place to buy them and the types that would be ideal? or even if the kit i noted below should be bypassed for something else.

Thanks

https://www.amazon.com/gp/product/B0785MXPHM/ref=ox_sc_act_title_1?smid=A2RB21RUGRFV4T&psc=1


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## Functional Artist (Aug 8, 2016)

Howdy,

It depends

...on the area you have to put the (4) batteries into

...how much weight the vehicle can carry (safely)

...& how long you plan on him riding at a time

IMHO smaller is better


Remember

...the more weight you add

...the harder the motor has to work 


I have used (4) 12V 12AH SLA (sealed lead acid) batteries like these on many go karts

https://www.amazon.com/ExpertPower-...id=1517327360&sr=8-3&keywords=12v+sla+battery



on my !Arriba! kart (48V 1,800W motor) 

...the (4) 12V 12AH batteries, (48V battery pack) usually lasts ~30 - 45 min

Check it out

https://www.youtube.com/watch?v=e6LV0A3l6jo


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## AmaToolBox (May 11, 2017)

Thank you, much appreciated. love the little kart, looks like a fun project.

At the size of those batteries, i could easily fit 8 to 12 (if i can squeeze in air flow) given how much space is available without the engine and gas tank. they are nice and small.

it's essentially one of these: http://chineseatvmanuals.com/images/fa-b50_wm.jpg

cheap 150cc Chinese ATV, engine was defective, and trying to go green and teach the kids something all in the same swoop.

thinking of even trying to add a transmission to the mix:
https://www.amazon.com/gp/product/B075RZGT5B/ref=ox_sc_act_title_2?smid=A36FCRXFCR9ZYN&psc=1







Functional Artist said:


> Howdy,
> 
> It depends
> 
> ...


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## Functional Artist (Aug 8, 2016)

That will be a great project for you & your son

Save your money, time & effort

...skip the trans

IMHO

The koolest thing about converting from a gas engine to an electric motor 

...whether it's a go kart, golf cart, motorcycle or even most cars is

...you don't need a transmission or a clutch


These 12V 12AH batteries weigh ~9 lbs. each 

...(4) of them will add ~35 lbs. (4 x 9 lbs. = 36 lbs.) 

...(8) batteries = ~72 lbs. 

...or (12) batteries = ~109 lbs.

...that's a lot of additional weight on a small vehicle

How long do you plan on him riding at a time? (longer than 45 min.?)

...if not 

IMHO 

...keep 'er as light & nimble as possible


I have also used 12V 18AH batteries on karts too, they are 

...~30% larger 

...weigh ~ 12 lbs. each (4 x 12 lbs. = 48 lbs.)


Here is El Dingo, it's powered by (4) of the 12V 18AH batteries

https://www.youtube.com/watch?v=zYWuGJTC0jQ


Here is the same kart with (3) 12V 35AH batteries & a much bigger motor

...it was so heavy in the rear that the steering was more like a suggestion than a command 

https://www.youtube.com/watch?v=AV0BQPm5JFo&list=PLoL6eIYWPO_ldEXj0hJX9nWGrLI8KmC7q&index=13


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## AmaToolBox (May 11, 2017)

Awesome Kart too!

The good news is the donor frame is an ATV, which means the batteries will be low center (preventing the needless wheelies)!

Looking to get a minimum of 30 min, though i'd like to get up to an hour.

how much time did you get with El Dingo in the two configurations? did the bigger batteries get you more time?




Functional Artist said:


> That will be a great project for you & your son
> 
> Save your money, time & effort
> 
> ...


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## AmaToolBox (May 11, 2017)

couple more questions... my battery (DC) knowledge is limited...

I know more MaH means more drive time, but how does that relate to volts...
i see 12V 100Ah batteries for around 200, but with the drop in volts (48 to 12), will the controller/motor have issues?

also, how do you charge the bank of batteries once they are connected together for the 48V?


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## Functional Artist (Aug 8, 2016)

Yes, the bigger batteries gave a longer run time

...but, not really enough to make up for the additional weight

...or loss of maneuverability & handling


I used to think that "bigger was better"

...or bigger batteries were the way to go

...but, as I tried the smaller, lighter batteries


I noticed, 

...the motors didn't seem to work as hard or get as hot

...the karts were actually faster 

...& they were a lot more fun to ride


Now, I start off as small & light weight as possible

...& upgrade (as necessary) from there


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## Functional Artist (Aug 8, 2016)

AmaToolBox said:


> couple more questions... my battery (DC) knowledge is limited...
> 
> I know more MaH means more drive time, but how does that relate to volts...
> i see 12V 100Ah batteries for around 200, but with the drop in volts (48 to 12), will the controller/motor have issues?
> ...


 
The voltage applied to an electric motor affects the RPM's

...most motors I have worked with produce ~70 RPM's per volt of input

...so @ 12V the motor RPM's would be ~840 RPM's

[email protected] 24V ~1,680 RPM's, @ 36V ~2,520 RPM's, @ 48V ~3,360 RPM's

So, @ 12V you would have a very slow ("power wheels" slow) type ATV


Also, the low voltage cut-off of a 48V speed controller is ~41V

...so, a 12V battery, no matter how big, (large AH) can not provide (nowhere near) enough voltage to power a 48V speed controller 


I just use a small 48V battery charger for electric scooters on my go karts

...like this (under $30.00 delivered) 

https://www.ebay.com/itm/48-Volt-2-...152157?hash=item20e7d0765d:g:ALEAAOSw32lY0wuL


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## AmaToolBox (May 11, 2017)

Thanks again for the detailed info! that seems to clear a lot up!.

outside costs, what are your thoughts on these batteries?
https://hobbyking.com/en_us/zippy-compact-5800mah-5s-25c-lipo-pack-xt90.html

thinking 3 would give me 55.5V... but it seems strange given the mah is 4x the other batteries (or i'm not understanding them right)


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## Functional Artist (Aug 8, 2016)

AmaToolBox said:


> Thanks again for the detailed info! that seems to clear a lot up!.
> 
> outside costs, what are your thoughts on these batteries?
> https://hobbyking.com/en_us/zippy-compact-5800mah-5s-25c-lipo-pack-xt90.html
> ...


 
Those are for remote control cars & planes

...not a vehicle a person can ride in or on

mah (milli amp hour) like divided by 1,000

(5,800 mah = 5,800/1,000 = 5.8AH)

So, (3) of them, wired in series, would only give you an (55.5V 5.8AH) battery pack


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## Duncan (Dec 8, 2008)

Hi Ama

If you use SLA's as recommended by Functional and discharge them by 80% they will last for about five or six cycles 
NOT what you want!

The batteries are the most important part of any project of this type - if you are OK with 5 or 10 minutes of run time then use Lead

If you want 30 minutes or an hour then you will need to bite the bullet and move into the 21st century

Then it is how much you want to spend - 

BEST would be some Leaf modules or a Chevy Volt module
like this

https://www.ebay.com/itm/Lith-ion-C...687242?hash=item2a99b9584a:g:qCcAAOSwUchaSnD5

Next best would be batteries for an RC car - these are very light - will give lots of power
BUT these are the "burn the house down" batteries and need to be treated with a lot of care and a smidgen of paranoia


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## AmaToolBox (May 11, 2017)

Oops, didnt catch the mah vs ah on the batteries. thanks, i wasnt catching that.

what about 2 of these instead?
Battery

with this controller:
https://hobbyking.com/en_us/turnigy-dlux-250a-hv-14s-60v-esc.html?___store=en_us

and this motor?
https://hobbyking.com/en_us/turnigy-rotomax-150cc-size-brushless-outrunner-motor.html?___store=en_us






Functional Artist said:


> Those are for remote control cars & planes
> 
> ...not a vehicle a person can ride in or on
> 
> ...


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## Duncan (Dec 8, 2008)

Those batteries would do - BUT charge them on a metal plate - Just in Case

That motor is designed for very high rpm and LOTS of air flow - great for an aircraft - no good at all for a kart


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## AmaToolBox (May 11, 2017)

Thanks

any objection to ones like these:
Batteries
?



Duncan said:


> Hi Ama
> 
> If you use SLA's as recommended by Functional and discharge them by 80% they will last for about five or six cycles
> NOT what you want!
> ...


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## PStechPaul (May 1, 2012)

I found one that might be better (LiFePO4, 12 A-h, 30A, 60A peak) and cheaper ($300 including charger):

https://www.amazon.com/48V-12AH-LIF...rd_wg=YMEL7&psc=1&refRID=D6VBYMVXNGG5A349A04P


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## Functional Artist (Aug 8, 2016)

Duncan said:


> Hi Ama
> 
> If you use SLA's as recommended by Functional and discharge them by 80% they will last for about five or six cycles
> NOT what you want!
> ...


 
Duncan, 

you did notice, were talking about a kids toy

(a HD kids size ATV but, still a kids toy)

You think it's a good idea to put a 2Kwh battery pack on a kids toy?


IMHO & from my personal experience

...for a kid size vehicle

...the 12V 12AH are the safest & most cost effective way to go

I haven't actually counted but, I seem to get hundreds of cycles out of them

...& as I said ~30 - 45 min run time, every time

I use these batteries on

Desteny's kart https://www.youtube.com/watch?v=4RjUPNhhPoE&index=3&list=PLoL6eIYWPO_keNZBEhfrew8UB5maK25Nl

Winston's kart https://www.youtube.com/watch?v=YZ6bcBy1O1M&t=11s

Zero https://www.youtube.com/watch?v=TCzH-m-mEgQ

& I did several test on 

E-lemon-aid (with a 24V 450W brushed ) https://www.youtube.com/watch?v=n1aysgJYGQ8

(a 48V 1,000W brushed motor) https://www.youtube.com/watch?v=AxKkIaE2feY&t=1s

(& with a 48V 1,800W brushless motor) https://www.youtube.com/watch?v=3yzOS4cE424&t=1s

...all with 12V 12AH SLA batteries

(some are over (3) years old, heavily used & still going strong)


* PLEASE, DO LOTS OF RESEARCH FIRST

DO NOT PLAY WITH LITHIUM BATTERIES

...until you know "more about them" 

...what your doing

...& how to handle them "safely"


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## Duncan (Dec 8, 2008)

AmaToolBox said:


> Thanks
> 
> any objection to ones like these:
> Batteries
> ?


Those would be OK
But a Chevy Volt module would be
A bit more expensive
Four times the capacity
And because it's OEM design and quality - much safer and more reliable

But to Functional's point with any of these you do need to do a bit of studying and be careful


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## Duncan (Dec 8, 2008)

Hi Functional
He is talking about using an ATV for an hour - that is not a "kids size" vehicle


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## AmaToolBox (May 11, 2017)

I am copying this!...
https://www.youtube.com/watch?v=3yzOS4cE424&t=1s

that 48V setup is fast enough for him! espically with that low/mid/high switch configuration.

Probably up the batteries a little tho 18Ah
or 35Ah




Functional Artist said:


> Duncan,
> 
> you did notice, were talking about a kids toy
> 
> ...


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## AmaToolBox (May 11, 2017)

Duncan said:


> Hi Functional
> He is talking about using an ATV for an hour - that is not a "kids size" vehicle


it is (or rather was) a chinese knockoff kids ATV. 

Similar to this:
http://chineseatvmanuals.com/servic...stroke-chinese-atv-service-manuals-p-323.html

small, light weight... with engine i could pick it up and toss it in the back of the truck.


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## AmaToolBox (May 11, 2017)

after a bit of reading, i'm going to stay away from Lipo for now. i can always upgrade later when the batteries die.




Duncan said:


> Those would be OK
> But a Chevy Volt module would be
> A bit more expensive
> Four times the capacity
> ...


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## AmaToolBox (May 11, 2017)

What is that volt/amp meter you have on the "e lemon" go kart?


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## brian_ (Feb 7, 2017)

AmaToolBox said:


> I know more MaH means more drive time, but how does that relate to volts...


Capacity - typically given in amp-hours or A-h - is how much current for how much time can be delivered. The capacity of a battery is the sum of the capacities of the cells which are connected in parallel.

The voltage of a cell is a result of the chemistry; it doesn't depend on the size of the cell. The voltage of a battery is the sum of all the cell voltages which are connected in series.

The energy you get out of the battery is the product of the capacity and the voltage; if (for instance) you have two cells of 1 A-h and 3.7 volts, it doesn't matter whether you connect them in series for 1 A-h and 7.4 V, or in parallel for 2 A-h and 3.7 V, it's still 5.4 watt-hours.

Of course, cells used usually have more than 1 A-h of capacity, and they are used in much larger quantities.


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## brian_ (Feb 7, 2017)

AmaToolBox said:


> outside costs, what are your thoughts on these batteries?
> https://hobbyking.com/en_us/zippy-compact-5800mah-5s-25c-lipo-pack-xt90.html
> thinking 3 would give me 55.5V... but it seems strange given the mah is 4x the other batteries (or i'm not understanding them right)


Those batteries each have 5 cells in series, so yes three of them in series would give you 15 cells in series, or about 55 volts.

Four times the capacity of what other batteries? These are built of flat cells, a stack of five cells in this case; they are not built up of some common size such as 18650 cells, for instance. The same line includes batteries built of lower-capacity cells, some with higher discharge rates, so the cells are not constructed exactly the same way internally, which affects the capacity.


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## Functional Artist (Aug 8, 2016)

AmaToolBox said:


> What is that volt/amp meter you have on the "e lemon" go kart?


 
That's a little meter that I rigged up in a box with a 9V battery

I originally built & used it to monitor & gather data 

...on the amps the motor was drawing 

...& also, the voltage level of the battery pack

Last summer, when I was doing some "Electric Turbo" tests (push button overvolting) on a kart called "El Turbo"

* Check out the (3rd) "Turbo Blast" ~3:20 the meter shows over 100A draw

https://www.youtube.com/watch?v=H-704ZyJkaU&t=29s


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## AmaToolBox (May 11, 2017)

That's pretty cool! how fast did that thing go? (note my son is not getting that option) and i dont see any breaks!

any comment on these batteries? not sure if "deep cycle" impacts anything.
https://www.amazon.com/gp/product/B00K8E0WAG/ref=ox_sc_act_title_3?smid=A33N703ELCFX8U&psc=1




Functional Artist said:


> That's a little meter that I rigged up in a box with a 9V battery
> 
> I originally built & used it to monitor & gather data
> 
> ...


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## Functional Artist (Aug 8, 2016)

AmaToolBox said:


> That's pretty cool! how fast did that thing go? (note my son is not getting that option) and i dont see any breaks!
> 
> any comment on these batteries? not sure if "deep cycle" impacts anything.
> https://www.amazon.com/gp/product/B00K8E0WAG/ref=ox_sc_act_title_3?smid=A33N703ELCFX8U&psc=1


El Turbo went ~15 mph in 24V 450W standard drive

...& jumped to ~20 mph when the "36V Turbo" was engaged 

"We don't need no stinkin' brakes"
(no, the brakes were not hooked up at that time)
(they are now)


There are (2) main kind of lead acid batteries

Starting batteries (give lots of power for short bursts) (like starting the engine in a car)

&

Deep Cycle batteries (gives steady power for a long time) these are the ones you want


I think that is what Duncan was referring to earlier

...if starting batteries are used to power a motor for an extended period

Yup, they'll die quite quickly 

...because, that's NOT what they were designed for

(operating outside their specified parameters)


* SLA (sealed lead acid), just means the battery is sealed up & maintenance free 

** Liquid acid, absorbent glass mat, gel etc. just describes the materials used in the construction of the battery.


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## AmaToolBox (May 11, 2017)

Functional Artist said:


> El Turbo went ~15 mph in 24V 450W standard drive
> 
> ...& jumped to ~20 mph when the "36V Turbo" was engaged
> 
> ...


Thanks for all the info! I think I have my list at this point.

I also think Duncan may have seen my other thread, where I am going to rebuild a Honda trx300ex... That one is going to need more power, though, at the price tag I may just rebuild it gas. I don't want to put 4k into it and have a 10mph quad. And based on power needs, I would probably have to be good with lipo.


How did your motorcycle build go?

Sent from my XT1254 using Tapatalk


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## Functional Artist (Aug 8, 2016)

AmaToolBox said:


> Thanks for all the info! I think I have my list at this point.
> 
> I also think Duncan may have seen my other thread, where I am going to rebuild a Honda trx300ex... That one is going to need more power, though, at the price tag I may just rebuild it gas. I don't want to put 4k into it and have a 10mph quad. And based on power needs, I would probably have to be good with lipo.
> 
> ...


 

Your very welcome, Team work! 

Yup, I think your right, I did not know that you were asking questions about (2) different projects in (2) different threads at the same time.
(probably shouldn't do that, kinda confusing)

My electric motorcycle conversion turned out great.

I think its BAD AZZ!

Here is the entire build

https://www.youtube.com/watch?v=bkLXnjOEB7Q&list=PLoL6eIYWPO_nZYYAumnkE7RowDoBCsuCh


IMHO 

Always start small, learn, get comfortable, then evaluate the situation, & make educated decisions about stepping up, before stepping up.

No one learns "how to drive", in a dragster!


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## AmaToolBox (May 11, 2017)

Functional Artist said:


> Your very welcome, Team work!
> 
> Yup, I think your right, I did not know that you were asking questions about (2) different projects in (2) different threads at the same time.
> (probably shouldn't do that, kinda confusing)
> ...


Agreed on the learning to drive! That's why my son's quad will be the learning one... Already swapped in a harbor freight 212 cc engine as a project, but now it's time to up the game!

Phase one will be ev transform, phase 2 may incorporate a gear box, phase 3 will be extended range. We will see how that plays out.

With the motorcycle, how fast did it her up to and how long does it drive? Might seek out similar hardware for the big quad.







Sent from my XT1254 using Tapatalk


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## Functional Artist (Aug 8, 2016)

AmaToolBox said:


> Agreed on the learning to drive! That's why my son's quad will be the learning one... Already swapped in a harbor freight 212 cc engine as a project, but now it's time to up the game!
> 
> Phase one will be ev transform, phase 2 may incorporate a gear box, phase 3 will be extended range. We will see how that plays out.
> 
> ...


 
I did several go carts but, El Moto was my first "bigger" electric conversion project

I wanted to start off small & slow (baby steps) until I understood everything & felt more comfortable 

So, I mounted everything on a Dingo go kart "El Dingo" (Electric Dingo)

https://www.youtube.com/watch?v=Ysib9TNE_sc&list=PLoL6eIYWPO_ldEXj0hJX9nWGrLI8KmC7q

It's kind of a long story but, I got suckered by an ad that said: 

"Build a super fast go cart" 

"NO expensive speed controller required" "

"let your battery voltage be your speed controller" 

...the ad even showed an example titled as "Concept of battery speed controller" which was just a "slide throttle"


Well, (from personal experience) it's NOT a good idea

It was like driving an old hot rod car with a shift kit in the transmission

...when you "got on it"

..."it would chirp the tires & kinda bang the gears

...really, really hard


It banged so hard that

...it stretched the chain & bent the motor mounting bracket on the first (& only) test drive

Then, I got a proper speed controller 


Back to the question

El Moto started off running at 36V (3- 12V 35AH SLA solar batteries from Harbor Freight)

https://www.harborfreight.com/12-volt-35-amp-hour-universal-battery-68680.html

...then, I upgraded to 48V by adding another, 12V 12Ah battery

When running at 36V it had a top speed of ~25mph & ~30 min. run time

When running at 48V the top speed increased to ~35 mph but, the run time seemed to decrease dramatically


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## AmaToolBox (May 11, 2017)

Other than switches and a volt meter (kicking around a few ideas for that one), this is what i am going with for my son's ATV.

Motor/Controller

Batteries - going with 4

Charger/maintainer (helps keep batteries alive)

And because it's a quad, a thumb throttle

I'm also going to make a dashboard, similar to what you did with the kart, with a volt/amp meter and i had a temp kit floating around i may add to monitor the motor and controller temperatures.

what's your source for things like switches/component boxes? i used to use radio shack, but they've closed up.


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## Functional Artist (Aug 8, 2016)

The motor & thumb throttle look kool

...keep in mind that (4) of those batteries are going to add ~100 lbs. to the ATV just in batteries
(24 lbs. ea. = ~96 lbs.) 
...the battery charger/maintainer seems very expensive for a 3 amp charger & it doesn't look like it has a cooling fan

Battery charger electronics get hot while in use, 

IMHO most "good" battery chargers that I have seen have a cooling fan

I have used this (~$30.00) 2.5A charger https://www.ebay.com/itm/141328152157?rmvSB=true many times, without a problem


I have done a couple of videos on the amp/volt meter 

...I will post them soon


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## AmaToolBox (May 11, 2017)

i use those battery minder chargers in a lot of different machines. They seem to bring a battery back to life really quickly. I've even had 10 year old ATV batteries that were done, plugged it into one of these, and the battery worked like new after a week. They are pricey, but saving just 2 batteries would make up for the cost.


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## AmaToolBox (May 11, 2017)

Functional Artist said:


> The motor & thumb throttle look kool
> 
> ...keep in mind that (4) of those batteries are going to add ~100 lbs. to the ATV just in batteries
> (24 lbs. ea. = ~96 lbs.)
> ...


Weight Wise, the gas engine, full gas tank, exaust and original electronics together was 102 lbs, so I figure 98 lb of batteries and a motor and new electronics is maybe 10 lb more in the end.

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