hey everyone
just another question about the DC to DC booster is it possible to add the in series or parallel to the same control as my battery has 2 output wires?
to increase voltage or amps

I am not sure what you mean? Batteries have a + and a - terminal, what two wires?

I wish to step up a battery from 52v to 25a but the booster says 30 but can output 22 constant.

Not sure what you are asking there either? Can you provide links to the hardware you are describing please?

Ron

 

I wish to connect 2 of this product in parallel to add up to 44 amps continuously as there rated at 22apms each if it's possible to a ebike controller.
As I wish to step a 52v 50a 23.4ah batter with 2 output cables up to 72v to an ebike controller
and out of curiosity could you connect them in series to the controller if theoretically it would handle the applied voltage?

 

just to clarify it has pairs of +&- wires.

 

would I also need diodes in line to stop feed back between the 2 DC to DC boosters?

 

I have never paralleled buck or boost converters so I can't honestly tell you that you can parallel a pair of buck converters and they will deliver twice the current. The ideal characteristic of a parallel power supply system is that each power module shares the load current stably and equally. I would suggest you give this a read where they mention parallel supplies. Buck or boost converters regulate based on output. I am just not sure how parallel will work out, hopefully another member here has some thoughts to share.

Ron

 

View attachment 319108
I wish to connect 2 of this product in parallel to add up to 44 amps continuously as there rated at 22apms each if it's possible to a ebike controller.
As I wish to step a 52v 50a 23.4ah batter with 2 output cables up to 72v to an ebike controller
and out of curiosity could you connect them in series to the controller if theoretically it would handle the applied voltage?

That power device in the picture does not appear to have any portion adequate for more than possibly ten amps. So if any claims are made that it can deliver more at any voltage, I would not believe them.
AND, as for getting more power out of motors by using more voltage to force more current, understand that there will also be a lot more heat. AND it is quite possible to damage a motor through heat so that even the scrap metal value is diminished because the copper is melted all over the steel.

 

perfect I understand you Mr bill and will have a read reloadron.

I also have 4 I want to use 3 7s 28v 60ah from 82ah prismatic batteries as there 10 years old with a charge of 1c.
according to the spec sheet what would you recommend I should charge them at if there is series to produce a 84v battery. or should I charge them individually.

also should I use a lower amp BMS as I will never need the 150+ Amp it can output in the near future (6 months plus)

I am fully aware all this is over kill and it's all just one big experiment/prototype project.

I'm currently running the bike at 25a 52v with a motor gearing of 11 to 1 and am looking for a cheap solution to get a speed boost untill I finish my new batteries.(2months)

I plan to upgrade motor and controller to a significantly more powerful one over the coming year possibly 6kw to 8kw plus in the future.
just exploring all the options
available.
as I have 2 of the bikes 1 for experimental purposes and the other my commuter.

 

Current motor is a bafang h720w heard motor. with a custom controller.

 

The good news is that you can charge a string of batteries in series with a power supply that will limit the current to the same as for charging a single cell. This will work as long as all of the cells in the series string charge at an equal rate and all have the same voltage across them as they charge. That is the primary purpose of battery management systems. Some methods of assuring equal charge are more complex than others, though.
Battery Management Systems are a whole huge area BTW.

 

ya I was personally thinking of using a solar charge controller if it was possible as there prismatic batteries.
or would I have to use a Ballance charger as it currently has no BMS as the operate in the range of 2.7 to 4.1 max charge discharge per cell and each bank is 14 cells 7s 2p li ion prismatic cylinder saft vl41m no BMS.

They will need to be ballenced to the same capacity before I link them up tho as they all have slightly different capacity due to them being 10 years old all around the 60ah range tho .

so I'm finding it difficult for a chap/reliable way to safely charge them as I can set the low discharge point on the bike control. but would much rather take the safest root possible. I'm aware of the dangers of lithium batteries.

would any one have any suggestions
if I'm compident and carfull coul I run no BMS use other means to stet the cut off point. or low voltage /over discharge or should I install n intelligent BMS on all of the packs. (expensive but presumably safer route). or could I use active ballansers to keep them balanced while charging.

 

 

I see that the battery pack in post#31 has a connector for some sort of monitoring system Is that a BMS that you have? or an option connector, or ???
I am not an expert in lithium battery applications and management systems and so while I understand about connecting battery strings, the care and feeding is a different story.

 

Here, you are working with very high power systems. 36V x 50A = 1800W.
Personally, I would skip the DC-DC converter and use the 36V battery straight to the motor controller. You will achieve maximum efficiency and optimum range.

 

I believe it is bus bars under and BMS lines on the PCB on top but no actual BMS connected if I could find the same connector.

it would save me so much time have no idea on what BMS was originally connected to it tho as there from a hybrid truck battery I believe. as they came in a big block case with about 12 or more not too sure tho.