Dual battery system

[Quinny]

You know what? ... I'm thinking the same thing ...

This is the third battery in a row I've had fail within a few years. I was thinking heat may be the issue. I knew it was stuffed since our trip up to the Clarence River. The fridge was turning off (when stationary) in the ute ... only the alternator was keeping it running.

I went back to the shop where I bought it from. They put a heavy test load on it (after driving from Lismore to Brisbane) - said it was flat ...

Missus has just got back with Chinese take away ... I'll get back to this later ...

[ag9111]

What sort off battery is it quinny. Hard to tell.
Deep cycle wet cell at a guess if you are running a vsr.
Maybe the vsr isnt letting full power through.
An auto elect should have the gear to check that

[Quinny]

Yes, deep cycle, sealed maintenance free 120 A/H. Dominator Brand name ? Can't remember ...

I put a meter on the aux battery - say it was reading 12.6 or something ... Start the engine, and the reading goes up to 14.5 (thereabouts). So I thing the VSR and alternator are working ok.

[ag9111]

Its not the voltage Quinny. Its the current that is important.
A stuffed VSR will pass all the voltage but not the current.

[coughy]

the battery needs to float quinny if getting charged al time will kill a deep cycle
so maintanace free that tells me it is a gel or a agm or a acid battery pls get 100% of model pls
how far away from the 1st battery is it???
u need a dc/dc charger as this allows the floating to happen and charge to get to the battery (amps) not volts

[ag9111]

All car batteries apart from the new Lithiums are lead acid.
AGM Yes
Gel yes
VRLA Yes
Wet cell yes
Deep cycle yes

The descriptor, gel, agm etc is how the acid is contained.

VRLA and calcium are maint free wet cell batteries so dont be fooled by marketing.
A DC/DC charger is not always needed and is often overkill. It can boil a wet cell battery dry. Even the "maint free batteries" can be boiled dry as they are valve regulated for overpressure ie VRLA , valve regulated lead acid.

[Quinny]

Thanks for the comments everyone ...

I believe it's a Super Charge MRV70 Allrounder - 105 A/H (I think the previous one was a 120 A/H).


The blurb:

760 Cold Cranking Amps and 105 Amp Hour Deep Cycle

Description: Starting and deep cycle battery all in one.
Application: 4wd, motor home/camping, maine & leisure power requirement
Features: Full 12-months* warranty. High density plate formulation for superior cranking with cyclic ability. Improved heat and vibration tolerance for long service life. EGX Technology.Maintenance-Free, "No need to add water".