is there a guide to making a batt?

[thegavo]

Is there any info on making a battery yourself, would love to have a go at making one and i guess it would work out cheaper than going to china for one, id need to make a lifep04 48v 20ah or 15ah??

[Pure]

I have never seen a "guide" so to speak, but there are plenty of build threads in the battery section. Go have a look for yourself.

[www.recumbents.com]

Making the actual battery or assembling a battery pack with a BMS?

[thegavo]

ha ha assembling would be just fine, would my bms not be any good??

[thegavo]

im struggling to find a build thread mind....

[auraslip]

this isn't quite done as I'm waiting to assemble my next pack and take pictures first, but it should be helpful -> https://sites.google.com/site/shelbyele ... and-safety

[biohazardman]

Y pedal has a good thread on pack building here. viewtopic.php?f=14&t=26621. As far as should you go 15 or 20 ah it will depend on your motor draw, battery's ability to provide amperage and the range you want. I have built several of the a123 cylindrical packs and they have been very good to me although I have not always been that way to them.

[dogman]

A few years back, there's lots of pack build threads, isn't the A123 one still sticky at the top of the page? Top of the page that is, in the battery section.

[amberwolf]

If you're going the cylindrical route, Leamcorp has at least one or two good threads.

[thegavo]

Ok here's what I did, as I've only been getting two to 3 mile on the 20 ah , I've removed the ribbon wire that had the low cell From the bms, leaving the other ribbon in place, (balance wires) I took the bike out tonight after checking all cell volts , still 3.8v bar the one at 3.2v, I figured the bms would not shut off the power if the balance wire was disconnected, I rode the bike with wot most of the time and no pedalling at all, even from standing starts and had it up to top speed for at least one mile on way back (34mph) for aprox 10 miles , I then tested voltage and all cells were down from 3.8 to 3.3 the duff one read 3.0 from 3.2, I plugged the ribbon back into bms and charged up, it took 50 mins 5a charger , and the cells were all 3.8 and the duffer was upto 3.3, dunno what this tells me really but it was great to be out on it for a longer blast, will it damage anything doing that? Will the bms cut the power based on balance wire that gets left in or do I have to be careful ??

[dnmun]

what it means is that the BMS is shunting current around that cell at 3.3V if that is how it ends up balanced after you charged it up to 3.65V with the cell phone charger. you will have to adjust the resistor divider bridge for that cell if that is all it balances to. but i would verify that you actually did ever pump it up to 3.65V first. if you did and it stays at 3.3V afterwards when it balances then the bridge needs to have another resistor added in the right place.

[thegavo]

No I did the charging with my normal charger which charges the whole thing, not tried charging the low cell individually yet