Battery and controller upgrade
I have no experience with this stuff and i am looking for an easy sollotion. I wonder if you can buy a niu or a super soco battery( or another one) and connect both batterys to run them together to get more power and change the controller to get better acceleration and higher top speed.
What could i buy to do this and how have you guys done it?
Hi there samuelS! no, it's no easy plug and play solution to my knowledge, you need to read on about it and do modifications. this is actually rather complicated stuffs compared to normal gasoline bikes, if your set up doesn't match you can end up in 2 scenarios (generally):
1:The best scenario, you don't get the power and top speed you desire. you power delivery will be lacking so you can't deliver enough amps.
2: The worst scenario, you draw too much power and will hurt or destroy you electronics.
I would not paralell batteries unless you know the exact construction of you battery designs, you need to know connections between each series block to know how much amp you can safely draw from the battery. let's say you connect 2 batteries like this:
Battery 1: safe amp is 40A
Battery 2: safe amp is 80A
"woho" you can draw 120A you might think, but no. you can't.
Lets say both batteries have a configuartion of 10 cells in paralel, in battery 1 you use 0,20mm x 5,5mm pure nickle between each cell groups, 10 bridges over to the next serie, that would give you about 40A safe.
in battery 2 you do the same but 0,40mm thickness, that would give you 80A. if you then connect them in paralel config you will have 20 cells. if you try to draw 120A from this you will stress each battery with 60A, and the 10 cells only made to carry 40A will carry 50% more current than they are designed to do. they will get hot and with heat and ohms law you get more resistance.
then put in mind that current always follows the path with least resistance, so what will happen? well ofc now a lot of current will be rushing through the thicked (and cooler) 0,40mm connection instead, if you are unlucky this will also heat up leading to increased resistance. with more resistans it means you'll get a bigger voltage drop and a increase of heat.
So in general, no. it's not recommended to put 2 batteries in paralel unless you know what you are doing. the safest way if you are going to do it is to either use 2 identical batteries (2 original super soco ts batteries for example) or that you limit your current draw. for example just draw 60A from the battery (which is a lot more then original) but not to go higher. It is hard to know where the limit is, but go low is my only recommendation, and replace the bms into something that can handle alot more current than the original.
I don't know how 2 super soco ts original bms handels in paralel, but if you get 2 daly bms (2 identical bms) you can actually run them in paralel for about double the rated current, but just becuase it works with daly doesn't mean it works with the soco bms
I agree in a way with you that you can't just draw two different currents from batteries connected in parallel, the lowest rated one will be the limiting factor in this case. the safety aspect is not the biggest issue if you keep the bms in place, this will protect you're battery from damage or even worse overstressing the cells. If both batteries are rather close to each other in current delivery it will not be the biggest problem. Ideal would be two exactly the same batteries, but super soco batteries are not widely availible second hand so other options will go then.
You have seen my setup and i used it for some days now and I am really please with it, I am going to change it now and going to use two niu 35ah battery blocks in parallel, these have a higher output rating giving me more juice, the battery was the limiting factor in my setup, I will put them in and see how the behave in the next couple of days. I will loose my dash battery indication for now, until I have my realdash finished (waiting for deliviery of two current measure cells) to monitor the current draw from both batteries.