Battery thread stripped - BMS less tan helpful

[pauldowrick]

Hi All,

I have stripped the thread on my Victron battery negative terminal (its aluminium)

BMS are more or less useless and emailed that it cannot be used any longer.

Does anyone here have any suggestions? I refuse to abandon a £1700 battery that is about 2 years old.

Paul

 

[Daydream believer]

Pack it with aluminium foil. Possibly plus super glue, but I am not sure if super glue is conductive. Others might comment

 

[john_morris_uk]

One word. Helicoil
It’ll be stronger than it was originally.

(And perhaps think of getting a torque wrench?)

 

[pauldowrick]

Torque wrench - definately

 

[IanCC]

I snapped a terminal on a new battery. Google repairing battery terminals or similar. So cut stump and filed flat. Then, with piller drill, drill correct diameter hole to tap for stud. Tap, i had never tapped before, and insert threaded bar. Done. Note: don't strip your new threads.

However i complained that i was just a punter and there was no warning on the battery or documentation that there was a max torque setting. I broke the stud twiddling a larger stud onto the thread with very little force.

I got a new battery even though they at first refused. One just turned up in the post!

 

[john_morris_uk]

But I believe it’s an internal thread with a bolt that is inserted on a Victron Lithium battery. Hence my suggestion of a helicoil.

 

[pauldowrick]

But I believe it’s an internal thread with a bolt that is insterted on Victron battery. Hence my suggestion of a helicoil.

Will a helicoil cope with the potential current of 400+ amps?

 

[jwfrary]

Is it an M8 thread?

 

[pauldowrick]

Is it an M8 thread?

yes

 

[pauldowrick]

The battery posts are also aluminium !!!!!

 

[jwfrary]

yes

Then probobly the best solution would be a helisolid.com insert HELISOLID - Helisolid vs Helicoil.

They are stronger and should result in a better surface area. It's really the lug that's doing the work in this instance rather than the bolt itself.

It will come a thread repair kit and will contain a twist drill and tap specially for it. You may need to modify the tap but cutting in off after the first pass to become a plug tap. This will be the minimum in terms or removed material from the post itself. Though I urge extream care with the drilling operation and reccomeneded you do this with the battery removed from the boat!

 

[pauldowrick]

Then probobly the best solution would be a helisolid.com insert HELISOLID - Helisolid vs Helicoil.

They are stronger and should result in a better surface area. It's really the lug that's doing the work in this instance rather than the bolt itself.

It will come a thread repair kit and will contain a twist drill and tap specially for it. You may need to modify the tap but cutting in off after the first pass to become a plug tap. This will be the minimum in terms or removed material from the post itself. Though I urge extream care with the drilling operation and reccomeneded you do this with the battery removed from the boat!

Good answer. Thank you. I might get an engineering works to dot it for me.

 

[john_morris_uk]

Will a helicoil cope with the potential current of 400+ amps?

I hope there aren’t too many devices wanting 400 amps on the OP’s boat! However even if there were, it’s the surface contact of the connector that carries the current. The threaded bolt provides the pressure to make the connection.

 

[pauldowrick]

I hope there aren’t too many devices wanting 400 amps on the OP’s boat! However even if there were, it’s the surface contact of the connector that carries the current. The threaded bolt provides the pressure to make the connection.

My bow thruster consumes 4.1kW at 12 volt. Ran it for a few minutes and nothing got hot or even warm.

 

[jwfrary]

My bow thruster consumes 4.1kW at 12 volt. Ran it for a few minutes and nothing got hot or even warm.

What battery is this? If its a 100 ah then 400 amps is pushing the battery to extreams

 

[rotrax]

Will a helicoil cope with the potential current of 400+ amps?

A weak aluminium thread did...............................................

 

[pauldowrick]

What battery is this? If its a 100 ah then 400 amps is pushing the battery to extreams

160 ah

 

[jwfrary]

160 ah

If it's just the one battery on its own then the max reccomeneded discharge is 320 amps about 4kw at 12.6 volts so your close to the limit of it is the one battery.

The load from a bow thruster is for a short time and victron are pretty conservative with the ratings

 

[pauldowrick]

If it's just the one battery on its own then the max reccomeneded discharge is 320 amps about 4kw at 12.6 volts so your close to the limit of it is the one battery.

The load from a bow thruster is for a short time and victron are pretty conservative with the ratings

Sounds good. I will be adding another 2 batteries as money allows.

 

[PaulRainbow]

Hi All,

I have stripped the thread on my Victron battery negative terminal (its aluminium)

BMS are more or less useless and emailed that it cannot be used any longer.

Does anyone here have any suggestions? I refuse to abandon a £1700 battery that is about 2 years old.

Paul

I would say, it's a bit unfair to slag the supplier off because you stripped the threads in the battery.