Asking for help on a 10S3P layout

fredskidoo

1 µW
Joined
Sep 13, 2019
Messages
3
Location
north Marin county
Hello all

First post here after scouring the site (and others) looking for a battery layout design to copy but to no avail.
I have a E300 and I want to put a 10S3P battery pack in it. The batteries will be installed vertically, in holders,
making 5 rows of 6 leaving enough room for the 10S bms and 36v controller in the front of the stock compartment.
I have had some experience with making battery packs but I need to get some experienced builders input on this one.
I can't get my head around how to get these setup as 10 series 3 parallel in this 5 rows of 6 batteries configuration.

Thanks for looking
 
Do you have a picture of the holders?

If each row has 6 cells, then the rows are split into two halves and placed in series. You may need to use sections of wire between the cell groups depending on how they are arranged.
 
Did your used E300 come with the two old 5s3p battery packs with connectors or was it gutted? If not remove the old 18650 cells from the battery housings and reuse the housings and connections to make two new 5s3p packs from new 18650 cells. Then join the two 5S3P packs together with appropriate wiring for 10s3p battery ...

[youtube]ZRR_u89y4gI[/youtube]

completely-wired-pack.jpg


Basically building a 10s3p pack like this and then split it in two with each half in its own protective housing connected together with appropriate wire & connectors. The advantage of two 5s3p sub packs is paralleling them together for balancing and bulk charging if you have access to a 6S Balance Charger. That way you could monitor the condition of the p-groups before and during charging say once a month or as needed.

Does this make sense or do you have something else in mind ? You may decide not to use a BMS if you use new brand name AOK cells, monitor the condition of the two sub packs and don't abuse them.
 
Fechter:
Here is a pic of the holders.
http://queenbattery.com.cn/our-prod...6650-universal-bracketholder2p3p-instock.html

I got the scooter with the two original lead acid batteries. I have 30 QB26800 Li-ions, brand new and ready to go.
The batteries will be standing on end in the original Razor E300 battery compartment with the controller and bms. (Not sure if I have to host am image online to get it to show up here). The controller is a 36v 800w YK31C TdPRo and a Li-ion 10S 36V BMS with 30a charge current and a 60a discharge current (common port).

I have lots of multirotor experience (letting out the smoke, LOL) with balance charging cells in series (3S, 4S, 6s etc) but I want to figure out the layout of the strips to spot weld the packs in a 5S3P configuration and wire up a 5S balance plug be able to maintain a balanced charge across the 3 parallel cells in a series of 5 with my 1s to 6s balance charger. And then there is the 10S BMS to somehow integrate and get functioning. This where my concern is.

So to eMarks suggestion - two 5S3P packs so I can connect them to my balance charger is pretty much what I have been thinking I would have to do. Even if it means not using the BMS to make the balancing function work as I am coming from having no experience or confidence in using a bms, much less to maintain a balanced charge.

Let me know your thoughts, suggestions and if I'm looking at things correctly. The configuration of batteries isn't set in stone (just space constraints) but my controller and bms voltages are. I'm not looking for fast or range as much as
the umphf on the hills (well, just one in particular).

Thanks for your time

Ethan
 
Those 26800 6800mAh, 20.4A(MaxCD) cells will give you plenty of range. Although cheap the controller (YK31C) should suffice, if not over-worked. It's integrated battery protection at 36v is approx 31.5v and at 42v approx 37.5v...
YK31C-diagram.jpg

Have you yet read this ES thread on the YK31C ... https://endless-sphere.com/forums/viewtopic.php?t=97600 ... in other words leave well-enuf alone ... unless one likes to experiment/modify and possibly take-on more risk.

If you decide to go with charging the two paralleled 5s3p sub packs (5s6p) with your 2s-6s Charger you'll need to make up two Y cables. One with jst 5s connection leads (20awg if available) for monitoring and bottom balancing(if necessary) before bulk charging. The other Y cable with banana plugs to Deans or XT60 connectors.

With good new cells you shouldn't have to do this 5s6p arrangement, but this mod (paralleling two 5s3p sub packs) is handy if only used to periodically monitor the condition of the p-groups and occasionally balance as they age.

Including a BMS with 30 of those 26x80mm cells could be a tight fit. That's why i suggested a closer assembly of cells in the previous photo than is possible with those QB2680 cell holders. This cell holder photo is for 18650, but U get idea those 5s3p QB2680 cell holders take up more space than previous posted photo with cells as close together as possible ... do what works BEST for you :thumb: ...

HTB1w2lrRFXXXXXDXVXXq6xXFXXXI.jpg

fredskidoo said:
I'm not looking for fast or range as much as
the umphf on the hills (well, just one in particular).
Hopefully, not too much umphf and not for too long.
 
eMark
Thank you for the insights. I guess I'm just unsure that this bms will reliably charge my 3p cells properly. As you say I could periodically balance charge the cells but how can the different wiring for the bms charging and the 5S balance charging leads co-exist? Is this not an issue? This is the mystery to me.

The BMS I have is this item https://www.ebay.com/itm/313259106053
and since I have no experience with installing these can anyone familiar with them
share some pointers I need to know before going ahead with installation?

Fechter
I had read your post about the controller failing in the open position and your accident. Serious stuff. Glad to hear you made it through all of that. So the Domino throttle I was able to find was $120. Sound about right? Is there anything or any way to achieve the same function at a lower cost? I have to agree that safety is paramount but I'm not able to keep throwing bills at this ride quite yet. I guess I'll have to complete building a functioning scooter to be able to justify that expenditure rather than buy now and take the loss if I don't succeed in the build.

I'm just waiting on the cell holders and a big roll of Kapton tape to arrive before getting started on the battery.

Finally figured out the photo upload.
I'll be raising the deck a bit but that's what 30 upright QB26800s look like in the E300's bucket.

PXL_20210727_023525549.jpg

Coincidently, if I put them in horizontally, they are exactly the same height.
I think that'll be better for all the connections, horizontal.
It is tight but this wouldn't be fun if it was easy.

PXL_20210729_021900144.jpg

Thanks again

Ethan
 
fredskidoo said:
I'm just unsure that this bms will reliably charge my 3p cells properly.
A BMS does not charge p-groups that need balancing with one another. Rather it's a very slow process of resistance discharging of any p-group(s) to match the voltage of the other p-groups. Unless your BMS has "active equalizing" its basic purpose is protection in case a cell/p-group should die (due to defect or abuse). Thus shutting down the battery to prevent something worse from happening :bolt:

These so-called "active equalizing" balance boards https://www.amazon.com/Balance-Lifepo4-Equalizer-Balancer-Transfer/dp/B091DZ36LW?th=1 aren't "equalizing" enuf for me. My p-groups can't vary more than 0.005V to 0.01V from one another when bottom balancing them before bulk/straight charging. The only thing these "active equalizing" boards are good for (IMO) are DIY battery packs made from salvaged cells or off-brand cells of questionable quality.
fredskidoo said:
As you say I could periodically balance charge the cells but how can the different wiring for the bms [dis]charging and the 5S balance charging leads co-exist? Is this not an issue? This is the mystery to me.
YES, they can co-exist if wired correctly. Let's forget about provision for splitting the 10s3p into two 5s3p packs for balancing and monitoring the p-group voltages with your 2S-6S Balance Charger. You've already got enuf on your plate to consider besides two of these ... https://www.getfpv.com/balance-lead-replacement-cable-5s-jst-xh.html ...
and these two ... https://www.amazon.com/PACK-Battery-Voltage-Checker-Alarm/dp/B00XQ91ECA/ref=sr_1_17?dchild=1&keywords=lipo+voltage+checker&qid=1627567878&sr=8-17
It would sure be nice if a reasonably priced 10S Li-ion/Li-Po Balance Charger were available.
fredskidoo said:
The BMS I have is this item https://www.ebay.com/itm/313259106053 and since I have no experience with installing these can anyone familiar with them share some pointers. I need to know before going ahead with installation?
Didn't it come with wiring instructions ?? Are you also upgrading to a 500W motor with your upgrade to 36V from 24V ?
I use a 36v 500w motor with the variable speed controller and throttle set up. I'm using a 10ah battery.
I have a 15 tooth motor sprocket and 44 tooth wheel sprocket for extra speed should I need to get places faster ...
https://endless-sphere.com/forums/viewtopic.php?t=97908 ... (scroll to bottom of page)
 
fredskidoo said:
I guess I'm just unsure that this bms will reliably charge my 3p cells properly.
The BMS I have is this item https://www.ebay.com/itm/313259106053
If you had this so-called "SMART" 10S 36V Daly ... "https://www.ebay.com/itm/233961060672?hash=item36792a7940:g:XrMAAOSwdfFgltNm ... you might get away with "reliably charge" or "reliably balance" :D

The reason for provision of a LVC alarm is because of the storage capacity of your 10S3P QB26800 6800mAh cells. Assume one reason for choosing these cells is so you don't have to charge your pack so often. If that's the case then provision for at least a voltage tester ... https://www.commonsenserc.com/product_thumb.php?img=images/Spy-Plat_600.jpg&w=225&h=169 ... to occasionally monitor the voltages of the p-groups between charges and when in storage.

The advantage of a LVC alarm is not for voltage accuracy as the p-group voltages of these inexpensive cell monitors could be off by say 0.03V from one p-group to another. Thus, for accuracy best to check individaul p-group voltages with a reliable DMM. Thus one reason for attaching a JST balance lead if only to check the variance between p-group voltages as well as capacity as the battery pack ages ... https://ae01.alicdn.com/kf/HLB1TOtzatzvK1RkSnfoq6zMwVXaC/LCD-Digital-Battery-Tester-Tester-Battery-Capacity-Voltage-Tester-Checker-For-LiPo-LiF-Li-ion-Battery.jpg

The main advantage of provision for a LVC alarm is as a double check besides your BMS. For example you can set a LVC alarm at say 3.20V or 3.00V in the event one of the p-groups should suffer from self-discharge. For example the LVC alarm would be activated should one of the p-groups reach say 3.20V; while the other p-groups range from say 3.50V to 3.60V. These LVC alarms can be set at 0.10V increments from 2.70V to 3.80V. Purchasing a so-called "SMART" Daly BMS should be worth the extra expense so an add-on LVC alarm or capacity checker isn't necessary.

FWIW, if you'd spelled his name correctly ... fechter (instead of Fetcher) ... it would help to encourage a response :wink:
 
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