Thread: Discovery 2 Dual Battery

There are a great number of different "isolators" available, a photo of the installation would help us.....

True, but its all good now its worked out

the isolator /solenoid may have been bypassed

so both battery's are hooked up full time

if its one of those digital things allow time for it to kick in and out

If you need a new isolator, get one from Tim at Traxide.
In my opinion, you can't beat them

Originally Posted by d2dave

If you need a new isolator, get one from Tim at Traxide.
In my opinion, you can't beat them

I've had a Traxide SC80 for about 6 years. A wonderful bit of kit. Why people use a DC - DC chargers is beyond me.

Originally Posted by Bohica

Why people use a DC - DC chargers is beyond me.

Hi,
A Li battery has a different charging profile, so a dc-dc is needed to get a full charge in to it.
Cheers

Originally Posted by austastar

Hi,
A Li battery has a different charging profile, so a dc-dc is needed to get a full charge in to it.
Cheers

There is a little more to it. A lead acid battery will only receive the amount of charge that it wants.

When flat it will take a large amount, but as it becomes charged the amount of current that it receives tappers off, reasonably fast.

A Lithium on the other hand, regardless of state of charge, will take what ever you throw at it.

As an example. I have a lithium battery which has 190 AH capacity. Lets say I use 150 amps whilst camping.

It is raining all day so my solar is not working. I decide to pack up and drive home. My D2 alternator is going to supply its full output to the battery, minus what the car needs.

Lets say I leave at night. I don't know what the D2 needs in AH for night driving. I will just pick a number, lets say 30 amps. I think the D2 alternator is 120 amps

This leaves 90 AH available for charging the lithium. The battery will accept this and it will take about an hour and a half to charge it.

So your alternator will be outputting its full capacity for one and a half hours.

Do this regularly and your alternator is not going to last very long.

This is why I have to run a DC to DC charger. I have one that outputs 50 amps max. This protects my alternator.

A DC to DC is also required for lead acid on late model cars that have a smart alternator.

Hi,
Yep, I have dialled the dc-dc to 20Amp for similar reasons. Since going Li with the house battery, I'm not chasing the last rays of sun with a solar panel.
Nice!

Cheers