The 150 series Dual Battery Guide

[Isiman]

Awsome, thanks to both LeighW and amts!

[LeighW]

All batteries these days are calcium hybrids, generally calcium these days refers
to a full calcium battery.

Marine Pro is a wet cell but use AGM mode on a charger.

Century 4WD again wet cell but use AGM

Optima AGM, could use wet cell mode on a charger as these have a higher terminal voltage but I would use AGM

Most modern batteries charge at lower voltages and don't like the wet cell setting on chargers.

just use the diode trick and a basic sbi isolator?

This.

[Isiman]

ok, two quick questions:
due to the lack of space for 2x N70 sized batteries under the bonnet, would a Optima yellow top (as starter) and Century Marine Pro 730 (as secondary for fridge) need a DCDC charger such as the Redarc BCDC 1225 OR just use the diode trick and a basic sbi isolator?

Second question:
what type of batterys are the following (ie, wet cell/calcium etc)
Marine pro 730
'normal' century 4wd starter motor
optima yellow top

Thank you, sorry for ignorance

[drivesafe]

Voltage 1hr after disconnecting Batt charger - 12.89V -
Voltage 9hr after disconnecting Batt Charger - 12.79V

(Battery not in car so 0 load on battery)

Hi Craig and with any other type of battery, that voltage reading would indicate a fully charged battery.

While you have given the Optima a good charge, at 12.79v, being an Optima Yellowtop, the fully charged OPEN CIRCUIT voltage is 13.1v.

Still sounds like the battery is good, just give it a bit longer on the charger, and see what you get.

[craigm]

Most likely could mjr. Just cant get the time to get it in there at present. Back from a lengthy holiday and got lots of work to catch up on...

[mjrandom]

Craig you could probably get it load tested where you bought it?

[craigm]

Might put the ARB fridge on it for a couple of hours then ....

[Symo]

How do you use a hydrometer on a sealed battery?

Cheers Andrew

Hahaha, of course my bad, was thinking it was a maintenance wet cell. *face palm*

Still, until it's loaded no way to check if it hold current.

[AJ120]

Could still have no capacity. That could be a surface charge, only way to tell is with a hydrometer.

How do you use a hydrometer on a sealed battery?

Cheers Andrew

[Symo]

Voltage 1hr after disconnecting Batt charger - 12.89V -
Voltage 9hr after disconnecting Batt Charger - 12.79V

(Battery not in car so 0 load on battery)

Could still have no capacity. That could be a surface charge, only way to tell is with a hydrometer.

[craigm]

Thanks for the info drive safe and a good suggestion on how to trick the charger. Thankfully, the Repco unit does charge from 0 volts. I've had on for over 24 hrs now and it passed the batt test mode ( tells you if it's a dud) so it's in float mode at present sitting on 13.89v
I'll take a reading after disconnecting it overnight and take a reading again in the morning. If it holds it's state I'll pop it back in the Prado tomorrow night...

Voltage 1hr after disconnecting Batt charger - 12.89V -
Voltage 9hr after disconnecting Batt Charger - 12.79V

(Battery not in car so 0 load on battery)

I use a 240VAC 7 stage charger to achieve a full charge after and before a trip.

[MelbournePark]

One thing I have learn't from investigating battery technology is that full re-charging is essential. Hence if you don't fully re-charge, then there is IMO little point in buying a "better battery". If thorough re-charging of all batteries is not assured, then its best to buy cheap IMO. Because if its AGM or valved wet etc, if the re-charging is not complete, then the battery will significantly degrade.

The complex bit for me now, is if I buy a trailer, and have a spare in my car for the fridge, then the car will be charging probably four batteries. If I shoved in an AGM as the spare battery in the vehicle, and had two valved wet deep cycles in the trailer, and a wet starter factory battery - the really important issue is likely how well all that is thoroughly re-charged. I have to say too, the idea of pulling batteries out to charge them properly has no appeal. I want something that is easy.

[craigm]

Thanks for the info drive safe and a good suggestion on how to trick the charger. Thankfully, the Repco unit does charge from 0 volts. I've had on for over 24 hrs now and it passed the batt test mode ( tells you if it's a dud) so it's in float mode at present sitting on 13.89v
I'll take a reading after disconnecting it overnight and take a reading again in the morning. If it holds it's state I'll pop it back in the Prado tomorrow night...