Thread: DC/DC charger under drivers seat

Originally Posted by clintooo

I'm in the process of re-wiring the car, and doing an exbox install. I'm going to swap out my house battery with a lithium. So I have a redarc 1225 DCDC charger (25Amp). I was planning on mounting that under the drivers seat, in the box.

Does anyone see any issue with that, will it get too hot? I was going to run some dynamat in the box to try and keep the heat down (and may wrap the exhaust if I need to). I could also put a vent on the lid. The charger doesnt have a great deal of cooling fins, so I wasnt sure how hot they get.

Has anyone mounted one there?

Cheers

Clint

I put mine in the ex-box. Put dynamat under the ex-box first. The ex-box can get pretty hot

cheers

yeh have run dynamat in the exbox on the base.

I just dont think I will have enough space in there to include the DC/DC charger in there with my fuse block and the other wiring.

But I figure if it isnt over heating in your exbox, then under the seat should be ok.

Originally Posted by clintooo

cheers

yeh have run dynamat in the exbox on the base.

I just dont think I will have enough space in there to include the DC/DC charger in there with my fuse block and the other wiring.

But I figure if it isnt over heating in your exbox, then under the seat should be ok.

I bolted the charger to the lid

OK, I'll bite Why do you need a DC-DC charger to charge a (presumably stand alone with integrated management, especially charging current limiting electronics) 12 volt Lithium battery ? Your avatar pic seems to show a non ECU controlled alternator Defender so why the DC-DC charger ?

Deano

Originally Posted by DeanoH

OK, I'll bite Why do you need a DC-DC charger to charge a (presumably stand alone with integrated management, especially charging current limiting electronics) 12 volt Lithium battery ? Your avatar pic seems to show a non ECU controlled alternator Defender so why the DC-DC charger ?

Deano

Thought lithium’s need a higher charging voltage 14 + volts. Didn’t think defers alternator went above 14v

Maybe so but my understanding is that the 'drop in' 12 volt Lithium battery replacements had integrated electronics that compensated for the different lead acid charging voltage/current values so that they were a 'plug and play' replacement.

Deano

Originally Posted by DeanoH

Maybe so but my understanding is that the 'drop in' 12 volt Lithium battery replacements had integrated electronics that compensated for the different lead acid charging voltage/current values so that they were a 'plug and play' replacement.

Deano

The catch word is “REPLACEMENT”.

If you were changing the cranking battery, then yes, a lithium can be a direct replacement, as long as it is the only battery in the system.

Clint intends to use his lithium as a house battery.

Lithium and lead acid batteries can not co-exist.

Once the motor is off. A lithium battery will simply back discharge into the cranking battery.

You can use a simple ignition controlled relay to separate the batteries when the motor is turned off, but this has other problems.

The use of a DC/DC device solves all the issues and charges the lithium with the correct charging voltages.

Originally Posted by drivesafe

The catch word is “REPLACEMENT”.

If you were changing the cranking battery, then yes, a lithium can be a direct replacement, as long as it is the only battery in the system.

Clint intends to use his lithium as a house battery.

Lithium and lead acid batteries can not co-exist.

Once the motor is off. A lithium battery will simply back discharge into the cranking battery.

You can use a simple ignition controlled relay to separate the batteries when the motor is turned off, but this has other problems.

The use of a DC/DC device solves all the issues and charges the lithium with the correct charging voltages.

I couldn't quite articulate my understanding of electronics that well

It will also isolates my house, plus I'll put a small solar panel on the roof and use this as a regulator.

I also figured that the battery management within the DC/DC may be better than what is located within the battery?? Is the internal BMS within the battery just to balance the load between the cells??