Recent content by geoff57

Thanks I’ll pick some up and set up a 4 cell test circuit will take a few days to get the parts and program the Arduino. Looked up on eBay and other sites and the avalibility of 1 or 2 ohm resistors at 2 watt will mean getting from china, I’ll build the circuit with a gap for the resistors to...

I want to build my own Bms not rely on a Bms bought off the internet where I am not sure what is going on. I will brake the designing of thiss down into several sections LVC, HVC, balancing, forced balance and amp limit on both charge and discharge. I want to be able up to 20 cells in series...

Hi If you still have the case and can open it up, you could change the cells for new ones depending what was used in the first place. Geoff

Hi An alternative watt meter https://www.aliexpress.com/item/1005003713078282.html?spm=a2g0o.order_list.0.0.b49118028fRtdS Not as high a wattage but you would never get close anyway. Geoff

Hi Since posting the initial post I have been testing the BG-8s With various sizes of battery I’ve used both 18650 and turnigy lipo, From 1000 mA hours to 26 ah. The small batteries balanced in 1/2 an hour the 25 took a day. I can live with those times my reasoning for wanting to change the...

I found this a while back on hobbyking it is unavailable at the moment but banggood and aliexpress both have them in stock. It has a battery balancing function available similar to the battery medic that has been out for years but it is a lot more accurate. It does not have a discharge and...

It’s been a while since I last had to build a battery pack and have forgotten some of the things that make a pack look neat. I’m building the pack out of turnigy 5ah 5cell battery “bricks” to wire them up I need to remove the heat shrink to get at the cell tabs. To keep the whole pack looking...

I have a 48v controller that has 63v capacitors in it. Will a 15s lipo (max 63v) work with the controller? At the moment it has a 14s battery it came originally with a 13s battery. Changing the controller would not be impossible but would not be easy. Geoff

I have the same bms configured as a 14s 45a. I have no problem with the number of cells it works with and an wire up the balance wires with no problem, from using previous similar bms boards I know how to wire up the positive power wires. The problem I have is with the negative power wires. I...

Had a look at the meanwell converters and for what I want it is too expensive since I use build my own battery packs with my own BMS I’ll put a 12v and maybe 5v output into the battery. Geoff

Hi I’ll want it to be a 12v output for the 5v I’ll use a dc converter on the 12v. As for amps it’s to replace the 12v dc converter on a e-bike that looks like a Vespa so I’ll dad about 5A so I have plenty to spare. Do tell me more about these meanwell dc to dc converters that go up to 177v. Geoff

Hi With a battery pack less than 60v there is no problem finding a dc converter to get a low voltage (12 or 5 v) output, once you go over 60v we run into problems. I mostly work with 20s lipo “72v” batteries, are laptop PSU’s still the best method to get a low voltage output from the battery...

They look ok, bus bars will not work all you will need is the silicone wires from the balance cables. Personally I would build the pack as several 1p packs the bus bar each end once that is done link across each cell that is in the same place with balance cable wire then attach to a BMS I...

looks like the way the original "duck tape" lipo4 batteries were constructed multiple cells in parallel then add them together in series. the old duck tape batteries never used copper bus bars but that was the circuit. geoff

Not sure that copper bus bars would work except for joining in parallel for the serial connection the tabs of the cells can be directly connected by soldering. When I build the pack I will document it but that is a few months off, the pack is going to be made with a custom BMS I am designing...