How many batteries can you get in an EM3EV bag?

[KINNINVIEKID]

Just got an EM3EV bag and I can only get 3 of my Multistar 16Ah batteries in.
How many batteries can you get in yours,particularly the 4s hardcases.
As a full time carer for my 2 disabled lads I cant afford to buy batteries to find they wont do the job.
Pictures would be an asset if possible.
I am running a BBS02 750W at 44.4Volt and looking for at least 32Ah
Thanks :wink:

 

[KINNINVIEKID]

My batteries in the EM3EV bag

 

[neptronix]

40ah of turnigy multistar ( in 10AH form ) fits according to icecube57, because they can be placed side to side.

 

[danielrlee]

Are you sure you can't get four 16Ah packs in the bag standing on their ends?

 

[KINNINVIEKID]

40ah of turnigy multistar ( in 10AH form ) fits according to icecube57, because they can be placed side to side.

He is using a Falcon EV bag though not an EM3EV.

 

[KINNINVIEKID]

Are you sure you can't get four 16Ah packs in the bag standing on their ends?

Tried it but it wont go

 

[danielrlee]

Are you sure you can't get four 16Ah packs in the bag standing on their ends?

Tried it but it wont go

That's a real bummer. I'll get you a photo of my 4S hardcase arrangement this evening.

 

[KINNINVIEKID]

Thanks :wink:

 

[danielrlee]

Hopefully you can make out what's what in this photo. There are 12x 4S 5Ah hard cases arranged into parallel sub-packs of 2x2. Two sub-packs are laying horizontally and another between them laying vertically.

If you need a better photo, let me know and I'll do you another.

 

[neptronix]

40ah of turnigy multistar ( in 10AH form ) fits according to icecube57, because they can be placed side to side.

He is using a Falcon EV bag though not an EM3EV.

The difference in size between the two bags is very small and they are generally the same shape.

 

[KINNINVIEKID]

Thanks for that.
I reckon I should be able to get 15 packs in with a bit of careful wire placement.
Happy xmas.
NEPTRONIX.. If my bag was just 20mm taller I could get 4 in
Shame that bag is so expensive to get over here.

 

[neptronix]

30ah 10S of 20C Turnigy in a falconEV bag.

Given that turnigy multistar contains 20-23% watt hours per the same volume of weight ( and size ) versus all other Lipo hobbyking has for sale.. that's how you get 40ah in there

It would be reasonable to assume that you could jam 30ah 12S into a em3ev bag despite it's smaller size - if you used the 10ah packs.

The hardcases are the least dense battery due to their case. The cells are also of lower quality. If you are going for maximum amp hours, i don't recommend them in the slightest.

 

[Alan B]

Good to see this discussed. I'm still waiting for my em3ev bag, shipped 11 Dec. Will check some batteries I have here in it.

I note that the inch dimensions shown in their website are not right, at least one of them is wrong (26 cm is not 20 inches). Presumably the metric values are right.

from their text and photos
80mm wide (compares to 100mm for Borg)
430mm long
260mm high
70mm forward height and rear perpendicular before bag angles up, effectively a triangle plus two rectangles

One key item is fitting the 80mm bag width. If this was 100mm it would fit my batteries better.

Some battery dimensions

6S 5000 Turnigy 25C 50x52x150 (have used these in mountain bike and Borg packs)

6S 8000 Multistar 10C 49x63x142 (to be used in upgraded Borg pack)

6S 10000 Multistar 10C 53x65x156 (don't have these)

6S 16000 Multistar 10C 68x74x173 (don't have these)

6S 8000 Zippy 30C 52x69x165 (have used these on recumbent)

I used to use Visio for layouts like this, but licensing has become problematic, not sure if anything I have will still work on that. Any 2D layout program should work for this, it helps to have rotations which a PCB layout program may or may not have.

Another issue is fitting all the wiring, I've made nice neat plans that were torpedoed by the wiring needed.

 

[KINNINVIEKID]

I am going to craft some dummy batteries out of polystyrene this week to see what fits.
I reckon I can use my 2 6s16Ah with either 4 of 4s10ah or if thats too tight then 4 of 4s8Ah.
That will give me 32 or 36Ah and 8.2 volts more than I have at present.

As stated,one of the main things is to make plenty of allowance for the wiring.

 

[Alan B]

4 of 4s is 16s, doesn't match 12s

 

[KINNINVIEKID]

I was thinking of running a 16Ah in series with 2 of 10Ah for 14S BUT after a bit of research I have changed plan and am going to get some 10AH6S or if they wont fit then go to 8Ah6S.

My plan then would be to ride with the 16s connected and when they get down swap over to the other batteries.

 

[Alan B]

OK, you can do that, but it is more practical to match the voltages and parallel. That lowers the load and makes things more efficient and avoids the decision and interruption to swap.

Still waiting for the bag to show up here.

 

[The fingers]

Has anyone tried using two side by side triangle bags? :?

 

[danielrlee]

Has anyone tried using two side by side triangle bags? :?

That's either absolute genius, or total stupidity and I can't work out which. I guess that the challenge would in the fact that the velcro straps would align to the same parts of the frame, but couldn't the hooks from one bag be joined with the loops from the other?

EDIT: I've just had a look at my bag to help visualise this and I'm wondering if it would be too wide to comfortably peddle, but I'm looking at a bulging bag with 2x2 paralleled hardcases.

 

[KINNINVIEKID]

OK, you can do that, but it is more practical to match the voltages and parallel. That lowers the load and makes things more efficient and avoids the decision and interruption to swap.

Still waiting for the bag to show up here.

The voltages do match but the Ah doesnt.
I could connect them till I use the 10Ah up then split them.
I use LV alarms so no danger of a low cell.

Has anyone tried using two side by side triangle bags? :?

Not enough room ,Would keep bashing my knees off them

 

[Alan B]

Voltages must equal in parallel, amp-hours parallel don't need to match (but in series do need to), they will share per the voltage. As long as the parallel cells don't go too low in voltage all is good.

 

[KINNINVIEKID]

Voltages must equal in parallel, amp-hours don't need to match, they will share per the voltage. As long as the parallel cells don't go too low in voltage all is good.

So you reckon if I parallel a 16Ah with 2 x 10Ah (all at 22.2V) I should be able to get all 36Ah out of them?
Obviously I would not take it that far as I never go below 3.5V.

 

[danielrlee]

Voltages must equal in parallel, amp-hours don't need to match, they will share per the voltage. As long as the parallel cells don't go too low in voltage all is good.

So you reckon if I parallel a 16Ah with 2 x 10Ah (all at 22.2V) I should be able to get all 36Ah out of them?
Obviously I would not take it that far as I never go below 3.5V.

Yeah, it'll be fine. As long as any cells/packs in SERIES are of a similar condition (internal resistance), they will charge/discharge at an equal rate. Any cells/packs in PARALLEL will remain at an identical voltage as all others in the same parallel group.

 

[danielrlee]

I've been doing some calculations regarding the various pack configurations discussed in this thread. Based on nominal voltage values, total capacity is as follows:

12x 6S 5Ah = 1332Wh
16x 4S 5Ah = 1184Wh
4x 6S 10Ah = 888Wh
1x 6S 16Ah + 2x 6S 10Ah = 799.2Wh

Of the four configurations listed above, neptronix's configuration of 12x 6S 5Ah gives the highest capacity. I'm convinced however that with the right configuration, the multistar packs would give a greater capacity still.

Does anybody have any other triangle bag compatible high capacity pack configurations to add to the list?

 

[KINNINVIEKID]

I've been doing some calculations regarding the various pack configurations discussed in this thread. Based on nominal voltage values, total capacity is as follows:

12x 6S 5Ah = 1332Wh
16x 4S 5Ah = 1184Wh
4x 6S 10Ah = 888Wh
1x 6S 16Ah + 2x 6S 10Ah = 799.2Wh

Of the four configurations listed above, neptronix's configuration of 12x 6S 5Ah gives the highest capacity. I'm convinced however that with the right configuration, the multistar packs would give a greater capacity still.

Does anybody have any other triangle bag compatible high capacity pack configurations to add to the list?

My 1x 6S 16Ah + 2x 6S 10Ah is x2 in series so thats 1598Wh
Your suspicions are confirmed

At an average of 15Wh/mile thats 106 miles which is at least 20 miles more than I am aiming for qhich is a nice buffer for headwinds etc.