Thank you, I did reach out to him couple days ago but i haven’t got a reply yet… I’ll email him and see what we can do
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They almost look a little too hot. Try turning it down a bit and see if the welds look less crispy haha. Then check if they still tear the nickel. If so, I would go with that.
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Ditto
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Hey,
is it okay to connect two different battery’s in parallel if they have the same voltage?
I have 2 Older 10s 4p packs laying around. One is using VTC6 another with no name 2200mah cells. They both have there individual BMS.
As far as i understand it the load will divide itself between the to packs in the same ratio as the internal resistance of the packs. So the VTC 6 pack will get a bit more load than the No name pack.
As long as i initially connect them with the same voltage everything should be fine?
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Yes, initial voltage is all that really matters when connecting parallel groups. They will be fin as long as they are really close, perhaps someone else has an exact number. (personally I would remain within the same .1v range.
After connected, the packs should contribute amperage between each other according to resistance values.
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So question, when wiring the BMS does the black wire goes to the negative lead of the whole pack? Or the negative of the first group?
Black to pack negative, red to pack positive. Wires are in the order of lowest to highest voltage points
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Hey guys,
Ill be making a Molicel p42a pack this winter and will be expecting to draw 30a-45a peak per P group. I was wondering what would be best between these two, or if anyone might have a source for better strips. 2WD 80100 so I will be using quite a bit of power.
I was really hoping to find something like 25x.2mm pure nickel to handle the amperage and use a single strip rather than cross bars connecting each P group. Like this here! The battery builders club
I was only able to find 25x.15mm and worry this isn’t enough to do what is shown above due to the high amperage. Since it is a solid single strip, could it be enough? Where could I find the 25x.2mm size that would be more suitable and offer lower resistance?
I was also able to find 15x.2mm which could handle the current but require many more spot welds and cutting making the battery in this traditional way. Would this be better than the 25x.15mm?
You want 30x0.2, I can sell you some in a couple weeks if you’re not in a rush
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So, question I got a little smoke when I plugged in my BMS does that mean I fried it, or would it be worse.
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You should really check your connections to the bms. Did you follow the provided diagram? I beleive there is a certain side of the series connections where you should solder the bms wire (someone please chime in on that). Also, check you don’t have your positive and negative terminals flipped or are trying to discharge out of the charge connection.
Otherwise, does it charge? is it wired for discharge or bypass? I guess try using a voltmeter and check if it reads for discharge, or if the charging works.
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I had a question about BulkBattery.com . They say that their minimum order for 18650s is 20 cells, but is there a minimum amount that you have to spend? It seems like people say a minimum of $150 but there is nothing like that on their website.
Yeah, you probably fried it. Double triple check your wiring order and connections.
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It looks like there isn’t a minimum order $ value that I can see. I’d say try it!
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There was a $150 minimum. But it may be gone now, they changed a bunch, more cell offerings and pricing, after the initial covid hit I think.
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No no no no that covers it
IR changes thro out the batery % and thro out it’s life and under difrent loads.
Basically the IR won’t always match overloading some cells then trying to charge them super quick when the load has gone. The harder you use the battery the worse it gets same with age. And charging Characteristics
different battery’s use difrent chemistry’s and are different. Unless you going to be super genital sutch as a huge power wall with lots of BMS watching eatch type of battery I will just cause issues down the line.
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This gose against parity mutch all manufactures advise surprised no one on the forum has spoken up sooner.
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Make your own its easy!
-Lay out plastic
-Apply resin to plastic
-Lay fibreglass on resin
-Roll out until thoroughly wet through. Apply more resin if necessary.
-Let cure.
Or if you are feeling really fancy, instead of plastic you can use glass, and once its fully wetted out, lay another piece of glass on top for a super flat and smooth finish on both sides. Note: not sure if it’s necessary, but I always wax my glass
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That’s what i was not sure about. The load is divided by the Internal resistance but the capacity does not necessarily have the same ratio. In my case the VTC6 pack probably gets most of the load but after the load is gone it gets charged up again by the other pack that has a crappy internal resistance?
I have often seen range extenders with the same voltage getting connected in parallel to the main battery.
So when this is a bad idea you should always use a CC setp down converter from the external pack to the main pack.
I already tested it while always having a clamp current meter to check everything and it seemed to work fine. While charging the current divided in the same ratio as the capacity. While discharging its hard to measure whats exactly going on with only a somewhat slow clamp meter.
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