Connecting batteries to fight the sag

Sooo, I got these three saggy ass evolve packs that cant throttle hard for more th an a second… paralleling them should take care of that right? Idk I tried linking two of them up earlier this year and it didn’t yield good results, I did a real hack job but this time around would be different I think. I dont wanna link all 3 but two of them would be a fuckin improvement yeah? Last time I just jumped the mains into each other and the lil guys into each other. This time I think I’d keep the charging ports separate and deal with that but the mains should be fine to fuse right? I feel lile this must’ve been asked here before in which case maybe I just need to figure out how to do more detailed searches or something. This hobby really knows how to make one feel like what they thought they knew really ain’t shit LOL! Hopeful to get some help and really kick off this learning curve…

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Yes; in theory. You might need a number of them. In theory you should be able to get a decent amount of range from them if they aren’t totally trashed, which they might be.

I bet @longhairedboy has a room full of those cells somewhere. Have any experiments been done over there?

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heck series them with a storemcore would be pretty interesting too

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Lol. This was fun to do, but I haven’t been able to convince myself to build a board around it. So it has sat like this on a shelf for months. I’m thinking about just attaching a buck/boost converter to it and using it as a variable voltage charger.

My advice would be to harvest the bms’s from those packs and sell them for the big bucks, then put that money towards a real pack. Here in Aus, those bms’s don’t sell for any less than 100AUD

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[quote=“nsteph, post:1, topic:45048”]
This hobby really knows how to make one feel like what they thought they knew really ain’t shit LOL!
[/quote] :laughing: yup…

@glyphiks Where do I get my hands on that blue helping hands?

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Hobbyking

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Yeowzaaaa. Thanks fellas! Uhh yeah, I got another 10s BMs layinnup here somehere… so deconstruct sell bms and learn me to weld right? 10s6p then learn to vesc! Fack, I already feel like I’m in over my head… there just ain’t enough time and so much reading to do!

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Not sure which cells your packs have but since the current you will be drawing from each paralleled pack will also be approximately halved that means less voltage sag in each pack. How much less depends on what cells those packs use and their internal resistance (which causes the sag along with with the connection and wiring resistance).

Adding that third pack can help but won’t result in as much of a power increase as going from one to two packs. IMHO, it wouldn’t be worth the size, weight, and effort needed.

You should be able to noticeably improve performance by paralleling two packs. If not, then there is a performance bottleneck somewhere that’s causing a loss of power…high resistance connections, wires too small, crappy welds, one or more bad cells, etc.

Every single thing between each individual cell and the ESC robs you of performance. Even small changes made to each of those things can add up to a lot of power lost or gained.

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yeah I’m confused because some of the evolves use these cruddy 10Ah pouch cells but the newer ones use a 10S4P 35E

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Ot defo ain’t the new ones. One is 2+y.o. bgt, the other is a bamboo gen2.

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The bottleneck explains my interesting results from my first try, shit connections. I just hooked the leads into each other. I’m gonna open em up and attach them at the pouches now. Has this been gone over before? This app is tricky to learn, my search results were totally bereft of anything similar but I really cannot be the first person to try this.

Surely not the first but my advice is to go slowwwww and carefully. Shorting out a pack can get…umm…exciting. :scream:

I don’t know how you’ll be connecting directly to the pouches but if it’s using something temporary like alligator clamps then you will have very high resistance connections.

Have you confirmed that all the p-groups are discharging down to about the same voltage when the BMS cuts out? That is, are all the groups performing at about the same level and none are running hotter than the others? Those two things can indicate where your performance loss might be occurring.

Are all your connections (when you paralleled the packs) tight and clean?

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No, none of that was done properly when I first tried. I am looking into this further now with y’all’s guidance and I will be rebuilding the stock board to test the cell readings with the remote. I’m guessing I’ll have a shit cell somewhere. And @Battery_Mooch while trying to look up some voltage sag shit unseen your write up on fb for vaping bats. Fkn small synchronicity letting me know in on the right trail. Shout out all you homies, I defo didn’t think so many big hittaz was gonna jump right on me like this. Thank you thank you thank you alllll

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I have somewhere around 80 evolve packs with no BMSs or connectors in a metal filing cabinet. I might let them go “as is” if somebody were to make me an offer. They’re all used, some mostly depleted, i have them from doing the cell replacement mod I do.

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I was expecting it in the trash at the end, you disappointed me :rofl:

I did something similar to this a while ago with the old Landwheel packs

It’s still running. It can be done but boy is it a pain to solder all those cells together lol

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Wow sweet thanks man, real helpful. Yeah thought itd be aan ex upgrade but like anything, no free lunch right!

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Ya not as ez as one might hope lol

Hey so uhh another quick question before I fkn got these shrimps. One of them is only maybe 50 cycles into its life but its fallen under voltage only measuring at 20v. This dude wont take a charge from the charger. Again this might be on me but I cant find posts about connecting two packs to try and bring his voltage up. Alls I know is that I put a resistor in line to let it go slowly but the charge should transfer into the one that reads 20v right? Or there’s another method where I’d need a rly low amp charger to let it sit on awhile right. Or perhaps its likely this is where the sour cell is located and shits gonna burn if I try to boost him back up?