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SunNrg batteries

grd

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Joined
Jul 17, 2021
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Hi, new here but wanting to put out a bit of a warning about these batteries.
Bought 2 200ah 48v lifpo4 to replace aging leads in home system.
Got them home and failed straight away with one where led didnt show (simple switch on / off volts display).
Pulled top off and cell block had moved across and short bus to lower tang on back of switch.
This caused the small white wire to melt / short. In pics you can see the green yellow i replaced the melted white with and the places where it shorted.
Top right to lower right on 3rd pic. So pushed block across and all good with new section of wire.
From what I have seen online even the cheapest chinese lifpo is much better built than this.
Made with pride in australia with high quality everything.
No covers on bus bars and the wrapped in foam bms sitting on top of cells.
This is just a warning not to deal with this mob.
Mine is a stationary situation, these come with castors and are intended for RV market as much as home. Upside down or crushed the batteries would short to metal case.
 

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Upside down or crushed the batteries would short to metal case.
That's not good. Also they are using copper busbars mounted to aluminum terminals which is fine if they used a corrosion inhibitor.
 
Bailing wire, duct tape, and bubble gum.
Perfectly appropriate if a DIY project, not a commercial product.

Are those burn marks I see on a couple studs & cell terminals next to the BMS?
 
yes, the thin white wire from lcd switch to battery (top right to lower right in pic showing all) had shorted / melted and dropped a section or two across terminals.
 
What the hell.

That battery is a fire hazard, report the manufacturer to the authorities.
 
a bit of an update and in terms of build quality its gotten even worse.
The 100amp circuit breakers are the auto style stuff that I know from experience will not last in this role.
I was prepared to replace them but thought they would be ok in short term.
Not so, this barrel design has the cable inserted loosely in the barrel and than secured with a small grub screw.
I didnt know that the cable was not a tight fit or that it was just a grub screw.
So after a little while with the cable not making proper contact and an increasing number of shutdowns and strange behaviour happening I pulled them off to find that they are a loose fit with no clamping at all. Plus its CCA cable.
You can see where the cable has been arcing against the barrel and causing all sorts of voltage spikes and battery capacity errors. With them removed all works well. Oh, and different diameter cable in a short section tween breaker and anderson plug.
 

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Just use a steel setscrew, and keep it out in the rain. After a while you'll have thermite with integral ignitor. ?
 
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