PINNED - ADD ON PACK Step By Step 30ah Pack build / pictures

[Burgerman]

For charging 1 x 100Ah sinopoly cell at once with that preset, choose a charge rate between 1/6th to 1/3rd capacity. So:

On a 100Ah cell, I would choose 1/3rd, so 30A charge is OK. Less is OK too but slower.
And set termination manually to 100thC to 200thC for testing with no balance. (So set to .5A to 1A which is 500mA to 1000mA).
Set time limit on CV to 2 hours.

[Mind The Gap]

Hi all, Home from hospital at last. Have charged batteries and put away in box for few weeks.
Been re-reading battery threads and noticed something in the Expresso addon thread about being one big battery, does this apply if mixing 8s7p 15amp main pack with 4s8p 12amp addon on pack. What I'm asking is it ok to mix 15 amp and 12amp together.

Cheers Paul

[expresso]

Hi all, Home from hospital at last. Have charged batteries and put away in box for few weeks.
Been re-reading battery threads and noticed something in the Expresso addon thread about being one big battery, does this apply if mixing 8s7p 15amp main pack with 4s8p 12amp addon on pack. What I'm asking is it ok to mix 15 amp and 12amp together.

Cheers Paul

Hi - Glad your home i think i was referring to the fact if you Connect an ADD ON lithium pack to a chair with Lead inside - then you leave it connected all the time - making it One Pack - you can charge it from the ADD ON pack only this way - thats how i do it with the chair that has Lead inside and ADD ON outside -

Now if you are going to have Lithium pack inside the Chair and also an ADD ON outside the chair - connected together - When in use its working as One big pack - BUT to charge that - you have to disconnect the ADD ON pack from the Main Chair pack and charge each one on its own separate -

i do my other chair that way since i have the same thing - 105ah inside the chair and the ADD ON 30ah outside - when i get home - i disconnect the Cable that is connected to the ADD ON going to the Chair Pack - then its two packs - disconnected from each other -

i have a few PL8s - i use one to charge the ADD ON on its own - and connect the other one to charge the Chair Main pack on its own also - - When the Charge is done on both packs - i then reconnect the Cable that connects both packs together as ONE Pack - and ready to use again -

you cant charge both packs when connected together - they need to be charged disconnected from eachother -

[shirley_hkg]

What I'm asking is it ok to mix 15 amp and 12amp together.

Cheers Paul

YES , no problem at all.

Now if you are going to have Lithium pack inside the Chair and also an ADD ON outside the chair - connected together - When in use its working as One big pack - BUT to charge that - you have to disconnect the ADD ON pack from the Main Chair pack and charge each one on its own separate -

i do my other chair that way since i have the same thing - 105ah inside the chair and the ADD ON 30ah outside - when i get home - i disconnect the Cable that is connected to the ADD ON going to the Chair Pack - then its two packs - disconnected from each other -

i have a few PL8s - i use one to charge the ADD ON on its own - and connect the other one to charge the Chair Main pack on its own also - - When the Charge is done on both packs - i then reconnect the Cable that connects both packs together as ONE Pack - and ready to use again -

you can't charge both packs when connected together - they need to be charged disconnected from eachother -

You are always good at making simple daily routines complicated , and I see it is really unnecessary .

Complete your work of the two packs as you've planned .




Buy a 8S extension cables , and cut it in halves . Extend the leads, and connect one half to a battery and the other half to the next .

Balance your two packs seperately. Connect the SB50 main plugs first, and then the extra 8S connectors .

Now all cells are inter-connected and PL8 will see them all, so no cell will be over-charged .

You have TWO charging connectors available now , and you can recharge the the two packs as ONE with any one of the them .

Unplug them all , and you restore them back to TWO stand alone individual packs .

Good luck .

[expresso]

My bad - i was under the impression he was making a ADD ON pack - same as i did -

Glad you are hear to correct me -

bravo Shirley -

by any chance - can you still make those hub adapters for my 646se chair ? as we spoke about a while back - ? if so i would be interested in it if you can get the rims also - i am thinking 2.5 inch rims would work - ?

you can PM when ever you get a chance

thanks again

[shirley_hkg]

My mechanics is always ready .

It's simple , if I have a hub to follow through ..

Happen to find a 636 nearby . Does it use the same hub ? I can borrow it for a while .

[shirley_hkg]

, does this apply if mixing 8s7p 15amp main pack with 4s8p 12amp addon on pack. What I'm asking is it ok to mix 15 amp and 12amp together.

Cheers Paul

Oh. Sorry . Slip through my eyes .

8S7P pack cannot work with a 4S8P pack , no matter what capacity they have .

[expresso]

My mechanics is always ready .

It's simple , if I have a hub to follow through ..

Happen to find a 636 nearby . Does it use the same hub ? I can borrow it for a while .

Hi shirley - thanks alot - i started a new section for this here

viewtopic.php?f=2&t=7885&p=118861#p118861

dont want to change the subject to tires here

[Mind The Gap]

, does this apply if mixing 8s7p 15amp main pack with 4s8p 12amp addon on pack. What I'm asking is it ok to mix 15 amp and 12amp together.viewtopic.php?f=2&t=6873&start=440

Cheers Paul

Oh. Sorry . Slip through my eyes .

8S7P pack cannot work with a 4S8P pack , no matter what capacity they have .

Sorry my mistake, should have read. Does this apply if mixing 8s7p 15amp main pack with 8s4p 12amp addon on pack.

[Burgerman]

Yes. You cant use 7S at all.

[garriew]

I made one end of the cable that goes directly to the batteries. When I was heating the end I could feel heat going up the cable. Maybe about 2 inches. Is this that bad?

The terminal ring is on tight though. I used flex, solder and crimped it.

[Burgerman]

flex

?

Flux? The heat will go up the cable as its copper. Transfers heat well.

[garriew]

Yes, I meant flux.

[ex-Gooserider]

As BM said, the cable is copper, which is an excellent conductor of heat, so you WILL get heat traveling along it, no way to prevent that....

What is important is to LIMIT the amount of heat to something that doesn't do any harm - excess heat will damage the wire insulation, can damage parts if soldering electronics, etc....

More of a concern is that if you heat the wire enough, the molten solder will wick up the wire away from the joint, making the wire into a solid, which is then a stress point that is likely to fail at some later point.

This means that you should limit the amount of heat to only what it takes to to do the job, and work as quickly as possible so that you don't add any more heat than is needed, and don't allow time for the rest of the work to get hot enough to be a problem.

ex-Gooserider

[garriew]

More of a concern is that if you heat the wire enough, the molten solder will wick up the wire away from the joint, making the wire into a solid, which is then a stress point that is likely to fail at some later point.

That makes sense. Thanks for the explanation!

[snaker]

More of a concern is that if you heat the wire enough, the molten solder will wick up the wire away from the joint, making the wire into a solid, which is then a stress point that is likely to fail at some later point.

I think it would never fail if it was soldered + wrapped by an adhesive heatshrink tube. garriew, try to break an terminal that you have soldered to see how solid it is. You might need professional tools to break it

[garriew]

Your lithium pack connects to the 0V and the 24V terminals.

I'm getting new batteries on my wheelchair next week and the technician is going to install the cable. When I told him it connects to the 0v and 24v terminals. He asked if that was the positive and negative.

Well, I don't know the answer. Since there are four posts, 2/battery, how would I determine the 0v and 24v posts? Or should I say how would he?

[Burgerman]

Your "technician" is an idiot.

Honestly thats like asking a vet which is the front and rear of your dog.

Find a competant person before yours hurts himself or you. If he cant tell just by a quick glance at the cables, and he can, then just test with a volt meter. The two that show 24 or 25 volts are it...

[garriew]

Your "technician" is an idiot.

Honestly thats like asking a vet which is the front and rear of your dog.

Find a competant person before yours hurts himself or you. If he cant tell just by a quick glance at the cables, and he can, then just test with a volt meter. The two that show 24 or 25 volts are it...

lol

Just to be clear.

One post will have 0v and I put the negative to it and one will have 24v and it get's the postive. Right?

[Burgerman]

Yep. If it reads 12 or 0 you failed!

[ex-Gooserider]

The problem isn't the part of the wire that actually got soldered, but rather the part NEXT to it... The solder turns the wire from stranded stuff that allows each strand to flex slightly differently when the wire is bent into a 'blob' that won't bend, so all the bend force goes into the area right where the solder ends. The result is repeated bending in one small area, leading to metal fatigue and failure - which is then hard to find because the insulation both holds the ends together MOST of the time - intermittent failures are harder to find, and hides it from visual examination...

Strain relief is a major factor in any sort of electronics / electrical project, you NEVER want to have flex at an attachment point if it can possibly be avoided, instead tie the wire down so that the flex happens in the wire, not at the joint....

ex-Gooserider

More of a concern is that if you heat the wire enough, the molten solder will wick up the wire away from the joint, making the wire into a solid, which is then a stress point that is likely to fail at some later point.

I think it would never fail if it was soldered + wrapped by an adhesive heatshrink tube. garriew, try to break an terminal that you have soldered to see how solid it is. You might need professional tools to break it

[garriew]

I'm going to start charging my batteries this weekend. Do I need to number each battery? Any tips?

[expresso]

I'm going to start charging my batteries this weekend. Do I need to number each battery? Any tips?

i always numbered them -

this is just an ADD ON - ? its not going to sit for a few months after you charge to check the discharge rate ?

[garriew]

this is just an ADD ON - ? its not going to sit for a few months after you charge to check the discharge rate ?

ADD ON. I was gonna let them sit for a few weeks.

[expresso]

ok you can do that even a month is fine -

the first ADD ON i did - i didnt do anything and just slapped them together - 36ah - and its going great -

the 30ah ADD ON - i did let them sit also for a month maybe and then try to match them best i can to keep it tight - its harder to do with small pack

number them or else you wont know what cell is which when you recharge them up after sitting a while - and write it all down on paper also -

[expresso]

http://www.chinafrey.com/enproducts_show.aspx?id=399

i just found these also which i want to make another ADD ON with - 60ah this time to replace the 36ah i no longer have -

its on a friends chair - her Pride Rival - first time out - it got 20 miles - which was great consider it was about 8 to 10 - 12 ish maybe before with just lead alone

its new MK 24 so a dozen more times of using it should improve - just goes to show it will depend on chair etc, - with my chair i got 25 miles with the same 36ah pack - lighter chair with just tilt -

will be replacing with this 60ah if price is good - waiting on there response -

[garriew]

http://www.chinafrey.com/enproducts_show.aspx?id=399

i just found these also which i want to make another ADD ON with - 60ah this time to replace the 36ah i no longer have -

That looks nice.

[garriew]

My 1st one is done. Took 20 minutes.

[garriew]

Batteries are charged! I didn't know what to write for the first five but saved the graphs. The others are:

6 = 273
7 = 209
8 = 233
9 = 339
10 = 312
11 = 436
12 = 241
13 = 252
14 = 289
15 = 253
16 = 245
17 = 502
18 = 245
19 = 243
20 = 323
21 = 254
22 = 357
23 = 266
24 = 280

[Burgerman]

11 and 17 are a bit away from the average. When you assemble the pack try to put those at the edge, as they are more likely to deteriorate then the rest.

Get the data from the graphs for the first few.

Assemble into 8 groups, of equal number, that have the same TOTAL mAh once they are added up.