I dont know how much you know/if this will be useful but I found this video. The first bit is common sense though… https://www.youtube.com/watch?v=MZyY1dpka7c
So, I’m leaning about BMS systems, how would I plug two 5s batteries into a 10s BMS?
I’m pretty sure you would need a balance adaptor/splitter to turn 2 5s balance ports to 1 10s one. (You are talking about the balance ports right?)
1 Like
Yes I am. So a series connector to connect the positive and negative and a balance adaptor to turn both the balance connectors into a 10s right? Do you know where I can find a lead? All I can find is 2*3s to make 6s on hobbyking…
1 Like
Here is my Lipo with bms build thread. I used 5 2s packs but 2 5s packs would work. I charge it with either a 42v 5a scooter charger or my lab power supply
this is my diagram:
3 Likes
A BMS will come with a balance harness with a 10s connector that matches it. All you need is two 5s extensions. You remove the male end, plug the female end into your battery balance connectors and wire the cut end to the balance harness from the BMS omitting the ground balance wire from each pack. Note: Of course, wire the cut ends to the BMS harness first, then plug them into the battery packs. http://www.ebay.com/itm/2x-NEW-8-INCH-JST-LIPO-5S-BALANCE-LEAD-EXTENSION-WIRE-ADAPTER-US-SELLER-/351549758139?hash=item51d9ff9abb:g:fWgAAOSwA4dWHp1y
2 Likes
I’ll have a look - I did a quick search but couldnt find any, maybe I’ll have to make one rather than import it…
So basically, the BMS will come with a 10s connector, I then need to take the balance connector cables from my batteries and put them into the 10s connector?
I read your thread which made it easier to understand with the pictures.
You could just cut the connectors off of your battery’s balance wires and solder (or use crimp connectors) the wires to the balance harness that comes with the BMS. I chose to use the JST extensions so that I could have a quick disconnect at the battery just to make it easier to maintain or replace individual packs if necessary.
Or much easier, cheaper, faster, and with a lot less space is using a bulk power supply and balance on the side. Something like a meanwell 48 volt adjustable supply and battery medic device plugged into balance wires
@Hummie is there such a thing as a 10s Battery Medic? This is all I could find…
https://hobbyking.com/en_us/hobbykingtm-battery-medic-system-2s-6s.html?___store=en_us
2 Likes
I’ve never heard of any of that lol
There’s a 12s version designed that u can find on endless-sphere if u search for “dumb shunt”. No 10s but if you know what you’re doing you could use the schematic/diagram on es and make it surely. I’ve been trying to get anyone to make the 12s version with a lower wattage than the es version and sell them to me. Maybe you? I use two of the 6s versions but they’re too slow
Does take a bit more care and involvement when charging but it’s standard practice for a lot of diy ebikes. without the bms I rely on the two low voltage cut offs on the vesc so I have the pack turn off when the cells average 3.6 and 3.5 final cut off. Much cheaper and faster charging and the biggest plus for me is using a single plug. I hate taking those little plugs apart.
Ah fair enough, I will use the vesc as a back up cutoff I think
I’ll take a look and see. Not sure I have time for anymore projects right now.
Do you use the 2x 6S balancers (cell medic) while the pack is still connected in series as 12S? How long does it usually take to balance?
P.S. That “dumb shunt” is pretty awesome!
I am using two 3s batteries in series, but the principles should be the same in that you can buy a 3s to 6s balance plug adapter which will allow you to charge the two batteries at the same time.