Friday, June 18, 2021

House Batteries update

LiFePO4 Upgrade

After 4 years of service and having replaced 2 batteries already, a 3rd Lead Crystal battery failed on us.
Availability of replacements in Australia was now non-existant with a 4-6 month lead time from the factory.
With numerous legal disputes ongoing between importers/suppliers/distributors, we decided to cut our losses and move away from Lead Crystal batteries.

We decided now was the right time to switch from AGM style batteries to more modern technology chemistry in Lithium phosphate (Lifepo4).

After another round of reasearch and various discussions with suppliers, we ended up in discussions with Anthony at Mictronix and agreed on buying a pair of Mictronix 24V 90AH / 2.2kwH Australian made drop in replacement lithium batteries.

Specifications:
  • Weight is only 20KG
  • Dimensions: 365 x 220 x 205 - similar size to a standard AGM battery
  • 80 amp continuous discharge current
  • 250 amp peak discharge current (1 second)
  • 80 amp continuous charging current
  • 29.2V recommended maximum charging voltage
  • low voltage cut off protection
  • Charge temperature range: 0°c - 55°c
  • Discharge temp range: -20°c to 60°c
  • 3 year warranty  
  • 10 year design life
  • Lithium phosphate chemistry (Lifepo4)
  • Drop in replacement for lead acid, SLA or gel batteries
  • Very high cycle life. 3000 cycles @ 100%DOD, 4000 cycles @ 80%DOD, 5000 cycles @ 70% DOD
  • Safe and inert. Each cell has a built in safety fuse to stop over pressure and thermal run away. Cells are not flammable or explosive like lithium ion batteries
  • A+ grade cells are used which are tested before leaving the factory and also after pack assembly
  • Impact resistant 3mm seam welded Aluminium case made in Australia. Powder coated in hard wearing texture finish black
  • Pressure relief, humidity resistant valve to resist the ingress of water
  • Hi quality terminals with M8 bolts for lugged connections. Terminal guards included
  • Built in battery management system protecting the battery against over charge, over discharge and a range of other parameters 
  • Able to be paralleled for more capacity. Unlimited amount of batteries can be connected together.
In comparison to the previous batteries, these 2 battery modules weight 40kg vs the 186kg of the 4 prior batteries.
We can safely extract 80% (144AH) of this 180AH battery bank as opposed to 50% (133AH) of the 265AH prior battery bank. The 2 new batteries fit easily in the existing battery box with plenty of room to grow if/when required.







Old battery setup - post from 29/4/2017
After consideration of available 24V 300+ AH house battery options namely AGM, Lead Crystal and Lithium/LiFePO4, we settled on Betta Lead Crystal Batteries for their resilience, simplicity and cost effectiveness sourced through Brian at System Logix.
We are using 4 x Betta Battery model 3-EVFJ-265 wired in series to provide us with 24V and ~350 AH at C20/20 Hour rate. Complete Data Sheet Here


A heavy duty box was fabricated and the batteries were aligned for optimal position under the dinette / second bed. The batteries are interlinked with 50mm2 / 0 AWG fine multi-strand battery cable and suitable crimped M8 lugs











Insulating and carpeting cab area

In an effort to improve the noise and temperature in the cab area over long trips, we have removed the old stiff brown factory vinyl flooring over the dry and factured bitumous sound deadener.

Dry ice was used to freeze and crack the factory bitumous sound deadener and a dull metal scraper was used to help lift it cleanly off the bodywork & floor.

Car Builders Stage 1 Sound Deadener was applied to the floor and vertical surfaces in the cab area - it is a ~2mm vibration/sound dampening mat. It consists of a butyl rubber noise absorption layer combined with an aluminium top layer. Joins were sealed with 0.5mm aluminium tape.

Next Car Builders Mass Noise Liner Lite was applied over it over the sound deadener - it is a heavy weight sound barrier, with a total thickness of 8mm and constructed of 2mm Mass Loaded vinyl upper layer, coupled with a 6mm closed cell foam to create an effective means of acoustic blocking. The flexible closed cell foam is water resistant and offers superior thermal insulation. Seams were joined with mass loaded vinyl and cyanoacrylate glue.

Finally charcoal coloured plush pile moulded carpet was sourced through TruFit Auto and trimmed into place for a quieter, cooler cab with a much nicer feel and apperance.