Lithium battery build

[chris69]

Ok it’s taken a bit too build this box but I’m finally there I can service the cells and disconnect my balancer when needed and fit all the cables and a bit of breathing space,I’ve built a small box to hold and compress the cells and in turn that box holds the bms and used that box to hold it in the big box by screwing it through the sides too easy .

230amp eve cells 250 amp bms with box 24 kg and it’s epoxy with a sheath of 200 gram cloth on the inside and just epoxy on the outside .

Just got to connect the balance leads charge it up too 3.45v with the lithium charger then disconnect the cells then top balance each cell with a variable voltage charger to 3.6 volts connect them back up and it’s right to use.

[Lovey80]

Nice job. Did you go with a Daly balancer too? Does it not turn on and off at pre-set voltages?

[chris69]

Yer got the 1 amp balance and I’m unsure yet Andy from off grid garage said it’s not good to leave them connected all the time so once it’s all charged up I can work it out from there.

Now I’ve got this one under my belt I might build a little 130 amp with a smaller bms so I can make a smaller box for a kayak and I’ve got thought off making a started battery with a super capacitor.

[marto78]

Thats pretty cool Chris.

Do you mind saying how much did that cost to build?

[chris69]

No it was about $1200 for the 4 EVE cells and a 250amp Daly bms with active balancer and free delivery and you get 3 year warranty on both bms and cells which is good when your building it your self ,for 230amp cells I’ve seen figures of 237 amps and 243 amps on discharge tests so I’m thinking they will be 230 amp cells form long time.

Theres a heap of youtube clips to watch to wire them up,I’m just sick and tired of lifting heavy agms around once you pick up a lithium battery your sold the battery cells and bms are about 19 kg without the box .

I had epoxy so cost about another 100 bucks for some 7 mm ply and fitting and foam to wrap around the cells and some polyimide high temp tape.

[Lovey80]

Chris is your active balancer the one with the little Bluetooth dongle? That one you can connect to the app and change the settings to the desired parameters and you can leave them connected all the time. It will turn itself off once the volts drop below that setting.

[chris69]

Ok that’s good to know there’s only one Bluetooth dongle in the box for the bms .

[Lovey80]

Is your balancer really small like a match box or about the size of an old iPhone?

[chris69]

No it’s the bigger one I’ve got to it sorted yer the dongle is for the balancer I’ve got it charging now and watching the app .

[chris69]

I will be ordering a second dongle I don’t like the idea of sharing it between bms and balancer.

[Lovey80]

You should be able to connect it up. Use the dongle to set the settings right. Say open start balance voltage to say 3.4v per cell and open voltage difference to 0.005 or 0.010v (what ever the lowest setting it will accept is). Then let it go and change the dongle back.

[chris69]

Been charging for 4 1/2 hours and the delta variation is only .003 so I’m happy with that cells only at 3.381 and the charger is not happy pumping in 20.7 amp non stop .

[Lovey80]

The delta means nothing until the cells are above 3.43-3.45.

[chris69]

Yer found that out once they got over 3.4v one run away and at 3.5 v I saw the balancer go to work, it’s all very interesting how these lithium cells work.

[chris69]

Fully charged and balanced the cells with a DC power supply and hooked up a 2000w inverter to the aircon very 😃IMG_0029.jpg