Inverter charging the camper from the trucks batteries.

[work2much]

Has anyone installed an inverter in their truck that they use to charge the camper?

My thought is that converting to 120v and connecting to the campers 120v system would allow a more stable charging source using the campers charger rather than the trucks alternator and all the DC line loss/heavy cable and possibly inconsistent voltages.

I would install a battery isolator that is switched by the ignition circuit as well as an in cab switch. Most of the time we don't need any more than what our solar provides but it could be handy to add charging while we drive when we get multiple cloudy days.

The inverter mounted in the truck would also give us a 120v power source when we don't have the camper with us. Our campers inverter/charger is adjustable for charging amperage so we could keep the amperage at a level that the trucks alternator could handle.

Potential issues could be engine compartment heat and protection from the elements. Maybe the inverter could be mounted in the cab.

Another negative could be the loss of efficiency converting 12v to 120v and back to 12v. Given that the trucks engine has unlimited power for this application though I think that may be a moot point?

Thoughts?

[S_Davis]

work2much wrote:

S Davis wrote:

work2much wrote:

S Davis wrote:
Why not just go with a redarc dc to dc charger probably cheaper than an inverter
large enough to power your converters charger and I believe they have a charging profile for your batteries.

Thanks for the heads up. I will research some more.

Looking on their page it looks like 50Ah is their biggest unit and the cost is more than a decent 2000watt PSW inverter.

I also like the idea of having 120v power available in the truck when the camper is off. This could be handy for doing odd jobs where you need to run some power tools etc.

I thought about stacking two of them but decided to go with an Outback inverter charger instead and run a 120 amp charging circuit off the truck to 500ah of batteries. I am going to use the truck for bulk charging and the outbacks charger to top off and maintain the battery bank.

What does your 120amp dc charging circuit consist of?

I am running 1/0 DLO wire from a 120amp alt to the rear seat of the truck where the 8d batteries will be, and then a run from there to a bed plug. I will be able to charge the 500ah of batteries in the back of the truck as well as the campers batteries. I am installing the 2800 watt Outback inverter charger in the truck near the batteries to power the camper, when the camper is not on the truck I will use it for a small fridge and micro in the truck at remote job sites.

[work2much]

S Davis wrote:

work2much wrote:

S Davis wrote:
Why not just go with a redarc dc to dc charger probably cheaper than an inverter
large enough to power your converters charger and I believe they have a charging profile for your batteries.

Thanks for the heads up. I will research some more.

Looking on their page it looks like 50Ah is their biggest unit and the cost is more than a decent 2000watt PSW inverter.

I also like the idea of having 120v power available in the truck when the camper is off. This could be handy for doing odd jobs where you need to run some power tools etc.

I thought about stacking two of them but decided to go with an Outback inverter charger instead and run a 120 amp charging circuit off the truck to 500ah of batteries. I am going to use the truck for bulk charging and the outbacks charger to top off and maintain the battery bank.

What does your 120amp dc charging circuit consist of?

[pianotuna]

With 1100 watts of solar I would not be bothering with charging from the tow vehicle.

[S_Davis]

work2much wrote:

S Davis wrote:
Why not just go with a redarc dc to dc charger probably cheaper than an inverter
large enough to power your converters charger and I believe they have a charging profile for your batteries.

Thanks for the heads up. I will research some more.

Looking on their page it looks like 50Ah is their biggest unit and the cost is more than a decent 2000watt PSW inverter.

I also like the idea of having 120v power available in the truck when the camper is off. This could be handy for doing odd jobs where you need to run some power tools etc.

I thought about stacking two of them but decided to go with an Outback inverter charger instead and run a 120 amp charging circuit off the truck to 500ah of batteries. I am going to use the truck for bulk charging and the outbacks charger to top off and maintain the battery bank.

[work2much]

mbloof wrote:
It sounds like you replaced the converter charger in your camper with one that has a LiPO profile? Mind telling us the make and model?

The type 27 battery in my camper is worn out and I have have a "BattleBorn" LiPO battery here to replace it. Ought to be "plug and play" excepting:

1. The converter+charger in my camper won't charge the battery at anywhere near the maximum rate it can handle. (needs replacing?)
2. My solar charge controller (I think) has a LiPO setting, I'll have to research it.

All and all it sounds logical. Instead of running big thick wires (and connectors) between your truck and camper just run 10-12AWG wire and connectors for AC instead and use your already purchased charger with the correct profile.


- Mark0

I removed the stock converter charger and transfer switch. I replaced that with a Magnum inverter with a built in charger and transfer switch. It can charge at 125Ah so the system has plenty of charging capacity that goes largely unused as we seldom plug into shore power and don't use a generator. I feel like an inverter could allow us those higher charging rates while we drive. Not sure if there is a dc to dc solution that will charge over 100Ah for our system.

My own Lithium battery was built using (24) 3.2v cells and does not have built in BMS like battle born or other drop in batteries that will help the battery from all kinds of charging and discharging sins. We control voltages by using specific charging values through high quality chargers and low voltage disconnects.






You can replace your charger/converter with a unit designed for lithium batteries. I thing Progressive dynamics manufactures it. That should help with your charging rate and SOC %

[work2much]

NRALIFR wrote:
If you want better alternator charging, consider a DC-DC charger instead of an inverter.

:):)

Can you give me an example of a unit that can charge at 100Ah and is programable for specific bulk, absorption and float voltages for my LFP? , Serious question I am interested. Also looking at a voltage drop calculator I would need 4/0 cable to stay under 3% line loss with such low voltage and high amperage. That is heavy and expensive. Weight isn't my friend.

For those who have upgraded their cable sizes what amperage are you seeing the alternator delivering? I wonder if the starter batteries close proximity to the alternator may cause them to see have higher voltage than the camper batteries thus slowing down the alternators current rate to the batteries farther away, even with massive cabling.

[mbloof]

It sounds like you replaced the converter charger in your camper with one that has a LiPO profile? Mind telling us the make and model?

The type 27 battery in my camper is worn out and I have have a "BattleBorn" LiPO battery here to replace it. The battery has a in built BMS so it ought to be "plug and play" excepting:

1. The converter+charger in my camper won't charge the battery at anywhere near the maximum rate it can handle. (needs replacing?)
2. My solar charge controller (I think) has a LiPO setting, I'll have to research it.

All and all it sounds logical. Instead of running big thick wires (and connectors) between your truck and camper just run 10-12AWG wire and connectors for AC instead and use your already purchased charger with the correct profile.



- Mark0

[NRALIFR]

If you want better alternator charging, consider a DC-DC charger instead of an inverter.

:):)

[work2much]

time2roll wrote:

work2much wrote:

time2roll wrote:
200 watts solar on the roof would also prove useful.

I have almost 1100 watts.

Wow I am surprised you need more charging capability. Must camp in poor solar conditions at time.

Do you carry a generator? Could consider running the generator en-route.

Does the lithium not have its own BMS to protect it? I really doubt the alternator direct would cause any issues. Put a volt meter on your truck 12v system and drive around a bit to monitor/evaluate conditions.

Just some random thoughts to cover the bases. Inverter off the alternator should work well.

Typically we camp in very good solar and our system provides what we need. We don't carry a generator and have no desire to do so. My generator compartment is where our lithium battery is housed.

The alternator charging would be a secondary charging source for long periods of inclement weather or when we are using a lot of air conditioning. I would feel more comfortable doing deeper battery discharging knowing that the alternator could add charging the following day while we travel in addition to the solar charging. Even with a large solar array replacing 500+ AH can be a challenge in a moving vehicle. Typically the solar contributes 30-65Ah I feel we could double that or better while we are driving.

It just something I am kicking around at this point. As I have mentioned a few times I was thinking about adding an inverter to the truck anyway and past that carrying the circuit to the camper seems simple.

I was just curious if anybody had set up a system like it, how it worked for them and any install advice they might have.

[time2roll]

work2much wrote:

time2roll wrote:
200 watts solar on the roof would also prove useful.

I have almost 1100 watts.

Wow I am surprised you need more charging capability. Must camp in poor solar conditions at time.

Do you carry a generator? Could consider running the generator en-route.

Does the lithium not have its own BMS to protect it? I really doubt the alternator direct would cause any issues. Put a volt meter on your truck 12v system and drive around a bit to monitor/evaluate conditions.

Just some random thoughts to cover the bases. Inverter off the alternator should work well.

[work2much]

cewillis wrote:

Wouldn't the efficiency loss be realized only in fuel economy which should be inconsequential?

I'd agree with the first part -- the engine is the energy source in both charge methods. Don't know about inconsequential - but probably. You - as in not me - have to know all the factors and do the calculation.
Heavy duty 12v is cheap, easy, extremely well tested, and known to work.

I am still left with needing a solution to charge my lithium battery. Right now the 7 pin 12v power circuit is disconnected. I don't want dissimilar battery types and voltages balancing themselves against each other and I definitely don't want the alternator charging the battery without strict regulation.

On our old camper with it's wet cell batteries I would definitely go with a system like yours. Reasonable cheap, reliable and simple.

[work2much]

S Davis wrote:
Why not just go with a redarc dc to dc charger probably cheaper than an inverter
large enough to power your converters charger and I believe they have a charging profile for your batteries.

Thanks for the heads up. I will research some more.

Looking on their page it looks like 50Ah is their biggest unit and the cost is more than a decent 2000watt PSW inverter.

I also like the idea of having 120v power available in the truck when the camper is off. This could be handy for doing odd jobs where you need to run some power tools etc.

[cewillis]

Wouldn't the efficiency loss be realized only in fuel economy which should be inconsequential?

I'd agree with the first part -- the engine is the energy source in both charge methods. Don't know about inconsequential - but probably. You - as in not me - have to know all the factors and do the calculation.
Heavy duty 12v is cheap, easy, extremely well tested, and known to work.

[work2much]

time2roll wrote:
200 watts solar on the roof would also prove useful.

I have almost 1100 watts.

[time2roll]

200 watts solar on the roof would also prove useful.