# [EVDL] Banding Winston/Thundersky Batteries



## EVDL List (Jul 27, 2007)

Anyone know if there would be a problem banding up to twelve (12) 400 Ah
Winston/Thundersky batteries together? I am aware that they need to be
banded with the provided jigs so that they do not bulge/deform as they heat
under use. When I ordered them, the most batteries that could be banded
together is six. But I assume this limitation is due to portabiliy issues: 
The jigs have carrying straps and six batteries is already about 180 lbs;
anything greater than this would be difficult to lift. For installation
into my conversin project, optimally I would like to band up to twelve
batteries together; this would allow inserting one more battery into two of
my battery boxes (the jigs themselves take up to 3/4" between banded sets of
batteries). Compressing twelve (rather than the maximum six) into a single
jig should work fine for keeping them from bulging or deforming, but would
this cause any other problem? Like excessive heat buildup in the middle
batteries? Any advice anyone can offer on this issue would be greatly
appreciated.



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## EVDL List (Jul 27, 2007)

Hi George,

There has been a lot of comment on the EVDL regarding swelling of LiFePO4 cells. It appears that if you do not abuse them they will not swell. By abuse, I mean specifically over-charging them. Apparently over-discharging does not cause swelling - it just destroys the cell. So, if you have a BMonS to prevent over charging and/or a BManS that works properly and does not cause over charging whilst balancing, then banding is not needed as the cells will not swell.

That said, I prefer to band cells as it means that the interconnects on a sub-pack do not put strain on the cell terminals and you can use the much cheaper layered, solid interconnects rather than braided ones. It also makes it easier to handle groups of cells.

The downside is that you can't stash the cells individually away into nooks and crannies in a tight installation situation.

How many and what type of band are you going to use? I ask as if you were going to use the plastic strapping type stuff then I would think you would need to use at least 8 straps but if using the standard metal ones, you may find they won't be taught enough to hold 12 x 400Ah cells together such that they won't move relative to one another when being handled as a pack - unless you keep them all on a level pallet or something. 

When I strapped my 8 x 160LFPs together with 5 plastic straps even quite tightly, when lifted at each end, the cells tended to sag a bit (1/4") in the middle and twist as well. They all sorted them selves out when put down again but I could imagine the ribs locking out of sync or something equally annoying which would probably mean taking the banding off to correct!

One thing you could do to prevent that is to insert some pieces of wood or plastic just the right size to be a snug fit into the rectangular hole that 2 adjacent case grooves make. This would then 'lock' the 2 cells and prevent movement between them. You would only need a couple of these per adjacent cell pair.

Heating really won't be an issue unless you intend to race your EV or you live in Arizona (apparently) especially with 400Ah cells as I imagine the max continuous current draw will be less than 1C. Consequently, I doubt you will see any heating at all - maybe a few degrees at most. Keeping them warm in winter is another matter.

Good luck and keep us posted. EValbum page?

Regards, Martin Winlow
Herts, UK
http://www.evalbum.com/2092
www.winlow.co.uk





> George Wagner wrote:
> 
> > Anyone know if there would be a problem banding up to twelve (12) 400 Ah
> > Winston/Thundersky batteries together? I am aware that they need to be
> ...


----------



## EVDL List (Jul 27, 2007)

> George Wagner wrote:
> > Anyone know if there would be a problem banding up to twelve (12) 400 Ah
> > Winston/Thundersky batteries together? I am aware that they need to be
> > banded with the provided jigs so that they do not bulge/deform as they heat
> ...


----------



## EVDL List (Jul 27, 2007)

My battery configuration is 12 under the hatch; 12 under the rear seat (this
is where the gas tank was in my Pontiac Vibe, so no exhaust, brake, or
electical lines ran under the full-span of the seat); and 10 under the hood
for a total of 34 (pack voltage 120 V).

For the two sets of 12, I was planning using the orginal metal bands used
for banding (up to groups of six) but joining them with stainless-steel
"worm-gear" hose clamps of the same width. The batteries would then be
placed one-by-one into the jigs already in the battery box, the bands added,
and the hose clamps tightened to compress the batteries between the end jigs
into the 12-pack. So I won't actually need to physically lift the
twelve-battery packs at all; they will be assembled directly into each
battery box.

I appreciate the great idea of inserting a couple of square dowels between
each battery in the pack to keep them from shifting side-to-side. Winston
Battery provided solid-copper straps for terminal connections between
batteries in a pack. The straps are not long enough to reach over jigs to
adjacent packs, so this way I will have to fabricate fewer terminal
connections than if smaller-size packs were used.

For the ten batteries under the hood, I'll probably join the two current
five-packs into a single ten-pack, space permitting (I won't know for sure
until I get the electric motor/tranny in the car).

Also good to know that battery-heating in use should not be an issue. I'm
using the MiniBMS system to keep the batteries in the proper charge range.



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| Moratorium on drag racing discussion is in effect.
| Please take those discussions elsewhere. Thanks.
|
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| Multiple-address or CCed messages may be rejected.
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## EVDL List (Jul 27, 2007)

The batteries LIKE heat. They perform better when hot. I un-banded them
and re-used the end plates with cables and turnbuckles. I filed a small
rounded notch in the aluminum to soften the corner on the cable. Now the
turnbuckles can be cranked up super tight, but can also be easily loosened
for maintenance. There are 3 banks of 12, 10, and 8 batteries. They are
Thundersky LFP260ah cells. No problems after 2 years. Cell bulging is
from over or under discharge. They will be damaged whether they are
restrained or not.

On Thu, Jul 26, 2012 at 9:16 AM, George Wagner


> <[email protected]>wrote:
> 
> > Anyone know if there would be a problem banding up to twelve (12) 400 Ah
> > Winston/Thundersky batteries together? I am aware that they need to be
> ...


----------



## EVDL List (Jul 27, 2007)

You'll get better performance out of them when they are hot - for a
short time. Heat will rapidly reduce their capacity though, killing
them much sooner than they would otherwise have lasted.

For all the comments that I've read about swelling only being a result
of over charging, I had a 100Ah Hi-Power cell sitting on the bench
that spontaneously swelled and was ruined overnight. I have no idea
what caused it. The terminals were not in contact with anything and it
was sitting next to an identical set of cells that were just fine -
all of them at 3.28 volts. I can only assume that it was a
manufacturing defect that was triggered by a change to horizontal
orientation after a year of sitting vertical.

- ian

On Fri, Jul 27, 2012 at 9:42 AM, Marcus Reddish


> <[email protected]> wrote:
> > The batteries LIKE heat. They perform better when hot. I un-banded them
> > and re-used the end plates with cables and turnbuckles. I filed a small
> > rounded notch in the aluminum to soften the corner on the cable. Now the
> ...


----------



## EVDL List (Jul 27, 2007)

George,

I don't think the Jubilee (as we call them over here in the UK) or worm gear-type clips will exert enough tension - unless you use a lot of them... one per cell case groove maybe.

Marcus' cables would be better but I don't know exactly which product he is referring to. Plastic strapping is easy and cheap and has the advantage of being quite elastic (obviously at considerable tension) and therefore is unlikely to cause any damage due to over-tensioning, unlike a steel system. My strapping can be seen here... http://www.winlow.co.uk/wychwood.co.uk/EV_Conversion_-_Part_2.html

As for BMS', I gather Willie McKemie has some considerable experience of that particular product - good and not so, I gather.

Tho I have not tried it, the Elithion's 'Lithiumate Lite' would be my choice but it would be somewhat more expensive than the MiniBMS - but much more useful in terms of cell monitoring/logging etc.

Sure, between sub-packs, you would have to use braided connects or lengths of cable.

Regards, Martin Winlow
Herts, UK
http://www.evalbum.com/2092
www.winlow.co.uk




> George Wagner wrote:
> 
> > My battery configuration is 12 under the hatch; 12 under the rear seat (this
> > is where the gas tank was in my Pontiac Vibe, so no exhaust, brake, or
> ...


----------



## EVDL List (Jul 27, 2007)

I've got string of 13 CALB 100Ah cells bounded by an aluminum plate on each
end. The plates fit snugly between the end cells and the aluminum battery
box itself. Holes drilled in the battery box allow 4 36-inch lengths of
all-thread to protrude through the sides of the battery box where they are
bolted in place from the outside, making the box sides themselves also part
of the clamping. Haven't had any trouble in 2 years. Plus, the 1/4-inch
all-threads act as battery restraints in case of a crash. I've got three
rows of cells in the front battery box fitted tightly that way, with the
all-thread running down the grooves between the cells. I think you could
turn the box upside down and the cells wouldn't fall out.

Bill

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Martin WINLOW
Sent: Friday, July 27, 2012 9:41 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Banding Winston/Thundersky Batteries

George,

I don't think the Jubilee (as we call them over here in the UK) or worm
gear-type clips will exert enough tension - unless you use a lot of them...
one per cell case groove maybe.

Marcus' cables would be better but I don't know exactly which product he is
referring to. Plastic strapping is easy and cheap and has the advantage of
being quite elastic (obviously at considerable tension) and therefore is
unlikely to cause any damage due to over-tensioning, unlike a steel system.
My strapping can be seen here...
http://www.winlow.co.uk/wychwood.co.uk/EV_Conversion_-_Part_2.html

As for BMS', I gather Willie McKemie has some considerable experience of
that particular product - good and not so, I gather.

Tho I have not tried it, the Elithion's 'Lithiumate Lite' would be my choice
but it would be somewhat more expensive than the MiniBMS - but much more
useful in terms of cell monitoring/logging etc.

Sure, between sub-packs, you would have to use braided connects or lengths
of cable.

Regards, Martin Winlow
Herts, UK
http://www.evalbum.com/2092
www.winlow.co.uk




> George Wagner wrote:
> 
> > My battery configuration is 12 under the hatch; 12 under the rear seat
> > (this is where the gas tank was in my Pontiac Vibe, so no exhaust,
> ...


----------



## EVDL List (Jul 27, 2007)

I like this idea. Question: what do you do from keeping the long sides from
bowing out? Do you put some brackets across the top and bottom at
intervals?

Peri

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Bill Dennis
Sent: 27 July, 2012 9:16 AM
To: 'Electric Vehicle Discussion List'
Subject: Re: [EVDL] Banding Winston/Thundersky Batteries

I've got string of 13 CALB 100Ah cells bounded by an aluminum plate on each
end. The plates fit snugly between the end cells and the aluminum battery
box itself. Holes drilled in the battery box allow 4 36-inch lengths of
all-thread to protrude through the sides of the battery box where they are
bolted in place from the outside, making the box sides themselves also part
of the clamping. Haven't had any trouble in 2 years. Plus, the 1/4-inch
all-threads act as battery restraints in case of a crash. I've got three
rows of cells in the front battery box fitted tightly that way, with the
all-thread running down the grooves between the cells. I think you could
turn the box upside down and the cells wouldn't fall out.

Bill

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Martin WINLOW
Sent: Friday, July 27, 2012 9:41 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Banding Winston/Thundersky Batteries

George,

I don't think the Jubilee (as we call them over here in the UK) or worm
gear-type clips will exert enough tension - unless you use a lot of them...
one per cell case groove maybe.

Marcus' cables would be better but I don't know exactly which product he is
referring to. Plastic strapping is easy and cheap and has the advantage of
being quite elastic (obviously at considerable tension) and therefore is
unlikely to cause any damage due to over-tensioning, unlike a steel system.
My strapping can be seen here...
http://www.winlow.co.uk/wychwood.co.uk/EV_Conversion_-_Part_2.html

As for BMS', I gather Willie McKemie has some considerable experience of
that particular product - good and not so, I gather.

Tho I have not tried it, the Elithion's 'Lithiumate Lite' would be my choice
but it would be somewhat more expensive than the MiniBMS - but much more
useful in terms of cell monitoring/logging etc.

Sure, between sub-packs, you would have to use braided connects or lengths
of cable.

Regards, Martin Winlow
Herts, UK
http://www.evalbum.com/2092
www.winlow.co.uk




> George Wagner wrote:
> 
> > My battery configuration is 12 under the hatch; 12 under the rear seat
> > (this is where the gas tank was in my Pontiac Vibe, so no exhaust,
> ...


----------



## EVDL List (Jul 27, 2007)

My box is wedged in pretty tightly, so I haven't had any problems with
bowing. But initially I had considered also running a piece of all-thread
from front to back by leaving a 3/16-inch gap between two cells close to
center. I had three pieces of aluminum about 1/3 the height of the cell, so
that starting at the top of the box between those cells it was:

Piece of aluminum
3/16 all-thread
Piece of aluminum
3/16 all-thread
Piece of aluminum

Hope that's clear.

Bill


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Peri Hartman
Sent: Friday, July 27, 2012 10:36 AM
To: 'Electric Vehicle Discussion List'
Subject: Re: [EVDL] Banding Winston/Thundersky Batteries

I like this idea. Question: what do you do from keeping the long sides from
bowing out? Do you put some brackets across the top and bottom at
intervals?

Peri

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Bill Dennis
Sent: 27 July, 2012 9:16 AM
To: 'Electric Vehicle Discussion List'
Subject: Re: [EVDL] Banding Winston/Thundersky Batteries

I've got string of 13 CALB 100Ah cells bounded by an aluminum plate on each
end. The plates fit snugly between the end cells and the aluminum battery
box itself. Holes drilled in the battery box allow 4 36-inch lengths of
all-thread to protrude through the sides of the battery box where they are
bolted in place from the outside, making the box sides themselves also part
of the clamping. Haven't had any trouble in 2 years. Plus, the 1/4-inch
all-threads act as battery restraints in case of a crash. I've got three
rows of cells in the front battery box fitted tightly that way, with the
all-thread running down the grooves between the cells. I think you could
turn the box upside down and the cells wouldn't fall out.

Bill

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Martin WINLOW
Sent: Friday, July 27, 2012 9:41 AM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Banding Winston/Thundersky Batteries

George,

I don't think the Jubilee (as we call them over here in the UK) or worm
gear-type clips will exert enough tension - unless you use a lot of them...
one per cell case groove maybe.

Marcus' cables would be better but I don't know exactly which product he is
referring to. Plastic strapping is easy and cheap and has the advantage of
being quite elastic (obviously at considerable tension) and therefore is
unlikely to cause any damage due to over-tensioning, unlike a steel system.
My strapping can be seen here...
http://www.winlow.co.uk/wychwood.co.uk/EV_Conversion_-_Part_2.html

As for BMS', I gather Willie McKemie has some considerable experience of
that particular product - good and not so, I gather.

Tho I have not tried it, the Elithion's 'Lithiumate Lite' would be my choice
but it would be somewhat more expensive than the MiniBMS - but much more
useful in terms of cell monitoring/logging etc.

Sure, between sub-packs, you would have to use braided connects or lengths
of cable.

Regards, Martin Winlow
Herts, UK
http://www.evalbum.com/2092
www.winlow.co.uk




> George Wagner wrote:
> 
> > My battery configuration is 12 under the hatch; 12 under the rear seat
> > (this is where the gas tank was in my Pontiac Vibe, so no exhaust,
> ...


----------



## EVDL List (Jul 27, 2007)

Hello,
Here is a link to photobucket showing a picture of the top turn-buckle (4
used).
http://s491.photobucket.com/albums/rr280/Ruckus99/?action=view&current=car026.jpg
Are they strong enough? I haven't seen anybody else do this, so time will
tell. I would have rather had steel, but the hardware store only had
aluminum. The cable is steel. They can be tightened till they sing like a
guitar string. I very much considered the super-heavy-duty zip-ties but
thought the cables would provide more tension and look better. I am not
sure if you can have TOO much tension. The Thundersky manual shows a
compression jig to fix a bloated cell. It is beyond extreme compression.
Have yet to hear of damage from over-compression.

As for which bms? I think it depends on your interest in data-logging and
such. Many controllers do that as well. I have a hard time paying several
grand for a bms. Regardless of the configuration, I believe over/under
voltage events MUST be prevented at a cell level. If it does that it will
be fine. Everything else is icing on the cake.

Marcus



> Martin WINLOW <[email protected]> wrote:
> 
> > George,
> >
> ...


----------



## EVDL List (Jul 27, 2007)

This is a great idea! I used (very large) all-thread to clamp the batts
down to the frame, but did not think of using the all-thread for horizontal
clamping as well. I think this is a much better idea than turn-buckles.



> Bill Dennis <[email protected]> wrote:
> 
> > I've got string of 13 CALB 100Ah cells bounded by an aluminum plate on each
> > end. The plates fit snugly between the end cells and the aluminum battery
> ...


----------

