Can you run 12V system from 24V battery pack

[Sportster]

Just so I got this straight. Your suggesting a battery isolator between two 12V 100A/H Lipo battery's when wired in parallel to a inverter?

Would that still be required if I draw 12V power from "Bat In" side of the converter?

 

[MisterSandals]

Your suggesting a battery isolator between two 12V 100A/H Lipo battery's when wired in parallel to a inverter?

This is just a bad idea, especially with lithium polymer batteries (very explody).

 

[Sportster]

This is just a bad idea, especially with lithium polymer batteries (very explody).

Is the bad idea the isolator or the batteries in series?

 

[MisterSandals]

Is the bad idea the isolator or the batteries in series?

I had to reread from the top and I am now wondering where you are on this?

Did you already purchase 24V items like the inverter or are you now switching back to 12V?

I missed the context switch back to 2x 12V batteries in parallel. To run a microwave from 12V, the amps start to get high:
Assuming you microwave uses ~1500W (standard for a roughly 1200W microwave).

1500W / .85 inverter efficiency / 10V cutoff = 176A This is manageable but will require significant wiring and fusing. With a 24V battery this becomes very manageable.

I completely understand that you want to keep your RV 12V, it is clearly the logical choice. The use of a 12V converter from a 24V battery is quite popular, cheap and easy to implement.

I missed to context switch to 12V when the isolator was suggested. There is a place for them but I would see if you need one before buying one. And what batteries do you have? Are they really Lipo batteries? Or really LiFePO4?

 

[Sportster]

Sounds like simplest is to just use a 12V inverter so I can use lights without having to power-up the inverter.

From my earlier post.

Yes they are LiFeP04 batteries, I was using Lipo as a typing shortcut, didn't realize that was a different item altogether.

Sorry if any confusion. I was adding "If I run" to make it a question.

Since I haven't yet purchased an Inverter & after suggestions that 24V system would be more efficient I was questioning to see if it was a viable option. Since I want to retain the existing 12V RV system, it doesn't sound like that's the route I'll go.

 

[JWLV]

If you take 12V from each battery to a common12V bussbar, then from the bussbar to a 12V fuse block, how is the 24V pack unbalanced if the 12V load is being shared? If it is for minor amperage consumption, that is what I would do.

Zap! Zap! And perhaps BOOM!

 

[gaudior]

Do you even need to do this?
If your Inverter is connected to or switched inline with the shoreline connector on your RV it should handle everything on its own.

 

[Sportster]

Do you even need to do this?
If your Inverter is connected to or switched inline with the shoreline connector on your RV it should handle everything on its own.

If your referring to me wanting to run 12V separate, to me it only makes sense, why run the inverter 24/7 when it's only needed 2-3hrs a day!

 

[houlster]

No, your batteries will quickly become unbalanced and become a charging nightmare.

Bringing this back up to ask a question. I can see this being a problem for lead acid. But if you're using LI batteries, each with their own, full blown BMS that protect against over/under charge/discharge, is this really still a problem? Won't the BMS of the battery that the 12v is being pulled from keep that battery full, and the BMS of the other battery in the series do its own thing?

 

[Zwy]

Bringing this back up to ask a question. I can see this being a problem for lead acid. But if you're using LI batteries, each with their own, full blown BMS that protect against over/under charge/discharge, is this really still a problem? Won't the BMS of the battery that the 12v is being pulled from keep that battery full, and the BMS of the other battery in the series do its own thing?

Do not do this, the batteries in series will be unbalanced.

Use a 24V to 12V buck converter.

 

[Jims94vmx]

Curious how to handle the electric slide (s) and electric landing gear going from 24 to 12 with a step down?

 

[Supervstech]

My fridge is either propane or 110V., no 12V. It runs quite efficiently on propane but occasionally it will blow out when travelling, figured a switch to 110V while travelling would solve that issue.

Keep in mind, propane / 110v fridges consume MASSIVE watts in 110V mode...

 

[Zwy]

Curious how to handle the electric slide (s) and electric landing gear going from 24 to 12 with a step down?

I run my truck camper jacks off the old AC to DC converter.

The AC to DC can be powered by the inverter or shore power. I have a switch ahead of it as this is the only purpose I left it in the camper for. You can use a 12V battery after the AC to DC converter, whatever chemistry you want. I just use a 12V jumper pack that has an AGM battery in it, we just carry it along in case the truck needed a jump start. I have run the camper jacks without a battery also.

I kept that circuit completely off the DC circuits in the rest of the camper. I installed a new fuse panel for the 12V circuits powered thru the buck converter and moved everything to that panel leaving the jack circuit on the AC to DC converter fuse panel.