safari dual battery help needed

[Ant]

hey guys. the safari has been running out of juice over about 3days of not getting used. today (one day before we go away for a week off roading ) one battery has nothing left after a good run yesterday, the other is holding its voltage at about 12.5v. so unless something strange is going on im guessing one is dead and the other probably not to far behind.....so the question........i know you are better off changing both batteries at the same time but I have a newish 700cca battery doing nothing at the moment so will it be ok to run two slightly different batteries for the next week untill i get back and then buy one new one the same as my newish one to replace the other one

[mudlva]

throw the dead one away put the spare in and go wheeling

in the perfect world yes do booth together but two older batteries together will still work fine

they will struggle if used for long hard winching tho

[Ant]

thanks. the newish one was bought a winch battery, dont have a winch on the safari yet but will get another the same when the winch comes.

[Suza]

Check your alternator, mine was doing that and the alternator wasn't supplying enough to fully charge both batteries

[mudlva]

yeah mate it will be sweet, go hard and have a good trip

dont forget a trip report and photos... ....otherwise it didnt happen

[DaveM]

Checked there isn't any draw from the battery while ignition is off?

[Ant]

yeah there is. got gps tracking and a 24-12 volt converter that is always on. both draw a bit, the batteries ususally last about 5days but lately its been about 3 days. it doesnt get used every day as we have a second cad and I have a work ute

[mudlva]

that's what is killing your batteries, std batteries don't like the low amp continuous draw off like you are talking about. it will also kill the new batteries real fast, that is why caravans and campers have the deep cycle batteries and cars and trucks don't

[coxsy]

yep low drain will pull power out of lefthand battery, its the one that add 12v to the 24vsystem when required, if that's low no start

[eins]

If you don't have an alarm or need the GPS for security you could put an red removable key type Isolator on the earth on left battery.

May slow someone trying to steel truck down and will stop draining battery if its a while between trips.

[waza4x4toy]

Charge both separately on a good three or 7 stage charger set to calcium if they are calcium, you cant charge a calcium battery enough if its flat or they have become unequal as a pair using vehicle alternator they need to be charge equalized to get them both up

a personal rule of thumb is don't mix batteries over a year old they just become too different to work together and one will absorb more charge leaving other not fully charged

You should only mix two identical! Batteries and not mix brands or same will likely occur.

If a calcium battery goes flat it must be charged by a cal/cal charger , jump starting and running round block does not cut it on these batts you could drive length of island with most standard alternators and not fully recharge a calcium bat.

Winch batteries if you can afford them use agm they cycyle well, crank hard and recharge quicker then other technologies

Batteries in hot engine bays will fail quicker also, hot slow wheeling with low air flow just wrecks batteries, eg batteries in hot middle east climates die quicker

So heat sheld and vent if in engine bay as will preserve expensive. Agm batts if you want longevity.