Prismatic LiFePo4 without terminal connectors, what to do?

RHTizzy

New Member
That is in effect what the epoxy is doing, no? The washer itself is only there for strength and surface area not for conductivity and should have no influence on the conductivity. So what bolts do people normally use anyway, zinc, iron, stainless steel, tungsten,...?
 

smoothJoey

Ooga Booga!
That is in effect what the epoxy is doing, no?
Not really the epoxy glue would be a very thin layer.

The washer itself is only there for strength and surface area not for conductivity and should have no influence on the conductivity. So what bolts do people normally use anyway, zinc, iron, stainless steel, tungsten,...?
Folks are typically using stainless steel for the hardware.
Stainless steel is a very poor conductor.
The washer goes on top of the lug, not between the lug and the terminal.
 

JMc

Solar Enthusiast
I just found this, inspired by @Sanwizard.


I have not tried it, if it didn't work you would have a mess so suggest you try it with a couple of bits of scrap first.
We made a radar reflector product that used conductive epoxy to bond large pieces of aluminum. The machined aluminum parts were first “plated” with a chromate-conversion film that made them more conductive, then a 3-5 mil thickness of epoxy was applied between the parts to bond them. There are two formulations of conductive silver epoxy, rigid and flexible, and for this application we used the flexible formula mainly because it had a 3-hour working time. Both are available from McMaster-Carr at a ridiculous price.

Our application required continuous and stable electrical conductivity between the parts but there was no measurable current flowing through the epoxy. Like all epoxies these conductive formulas have temperature limits (~ 230F, far lower than metals) and I think that is where the issues might arise for use with LFP battery terminals. At high currents I can see hot spots developing in the epoxy film and these would degrade conductivity leading to more heat, more degradation, etc. In effect a thermal runaway on the terminal likely ending in smoke and flames.
 

RHTizzy

New Member
I'll make sure to test the epoxy before I try to apply it. I'll try various thicknesses to see how it conducts and whether a washer included has any effect. And yes, SS is a really poor choice for this application.
 
Last edited:
Top