120 Series Prado Dual Battery Woes

zacthegreat5
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Posts: 48
Joined: February 15th, 2013, 3:33 pm

120 Series Prado Dual Battery Woes

Unread post by zacthegreat5 » October 22nd, 2014, 12:55 am

Hey all
Mum in law has a 120 prado with just an opposite lock isolator, no smart charger or anything. Just the old isolator. The second battery never seems to be charged. drive for 3 hours and nothing. Yes it does get deeply discharged but it should still charge up enough to cool the fridge down after hours of driving shouldn't it? I've heard the altenator in these is some low amperage one or something isn't it? Should I turf the isolator and put in a redarc or don't you think that's the problem?
Thanks for any advice
80 series! 2" ironman profoam lift, 33" maxxis 980. Dual batts, solar, inverter, rear bar with dual swing aways, roof rack. Humble beginnings.

Muckinhell
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Posts: 2079
Joined: November 16th, 2006, 9:25 am

Re: 120 Series Prado Dual Battery Woes

Unread post by Muckinhell » October 22nd, 2014, 10:13 am

yes it should run while driving if the battery is being charged, have you checked the aux battery for voltage to see if its is getting any charge, put a multimeter on it while the cars running with a few revs after 5 mins or so as the isolator should prioritse starter first and whe it sees its full change to aux battery, can check by checking main batt volts upwards of 14.4 volts and then aux batt for same voltage....what exact type of oppoiste lock isolator and how old is the battery? what is the aux batt volts as well when car switched off and no load, if its under 11 volts there abouts its more than likely buggered.
hope this helps.

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