Victron Energy: Alternator/Solar Charging - LFP Battery System

[shade]

I would be curious to see a total cost figure when it's all said and done. Won't be cheap, but lots of power is quite valuable.

I'll have a tally, but I expect it to be around $3500 - $4000 when all of the wiring is added in. That would be the system price, which won't include tools like crimpers or a bench-top power supply. Going for a 160Ah battery added some costs over a more common capacity of 100Ah, but the price per Ah on that model was too good to pass up. Everything in my plan would be useful with a lead battery system, and that single change would reduce cost by $1500.

I think this is one of those projects where it's better to commit to either going the bargain route (DIY LFP battery in particular) or more to the top end. Either way can work well, but trying to hit the middle on price may be more difficult. Which corners do you cut, and how will that impact the system?

Managing an LFP battery system is new for me, and I didn't want to take on a DIY battery project at this time. I may change my mind in the future, and I've enjoyed reading about battery building. Past that, once I decided on a Victron battery, staying within their system made sense, even if I could save some money using non-Victron parts elsewhere. As the market matures and more solutions become available, it'll be easier for a DIYer to handle system integration. At the moment, I have more money than time or experience, so spending more to have Victron do that work is worth it to me.

 

[Hillbilly Heaven]

Updated system overview. Short of using an all-in-one alternator/solar charge controller, this is as clean as it gets. I like that both the DC-DC charger and solar charge controller are both smart enough that I can regulate charging parameters, leaving the charge disconnect to truly function as an emergency control.

The only significant additions I can foresee will be an approximately 1000W AC inverter, and possibly a second solar charge controller for a 100W panel I may use to allow remote placement. Both will be simple to integrate later.

View attachment 545400

I haven't had time to open the crate, but the battery is reporting 12.92V, with all cells at 3.23V. When I connected via VictronConnect, it auto-balanced the cells and updated the battery's firmware.

I like it. Simple but very functional and protective.

 

[shade]

I like it. Simple but very functional and protective.

Thanks. Now I need to produce a real schematic to put it all together.

 

[Alloy]

I'll have a tally, but I expect it to be around $3500 - $4000 when all of the wiring is added in. That would be the system price, which won't include tools like crimpers or a bench-top power supply. Going for a 160Ah battery added some costs over a more common capacity of 100Ah, but the price per Ah on that model was too good to pass up. Everything in my plan would be useful with a lead battery system, and that single change would reduce cost by $1500.

I think this is one of those projects where it's better to commit to either going the bargain route (DIY LFP battery in particular) or more to the top end. Either way can work well, but trying to hit the middle on price may be more difficult. Which corners do you cut, and how will that impact the system?

Managing an LFP battery system is new for me, and I didn't want to take on a DIY battery project at this time. I may change my mind in the future, and I've enjoyed reading about battery building. Past that, once I decided on a Victron battery, staying within their system made sense, even if I could save some money using non-Victron parts elsewhere. As the market matures and more solutions become available, it'll be easier for a DIYer to handle system integration. At the moment, I have more money than time or experience, so spending more to have Victron do that work is worth it to me.

$3.5k-$4k, Ouch. What items did you drop to get to FLA at $2k-$2.5? Would the FLA system need a sealed vented battery box?

 

[Photobug]

I'll have a tally, but I expect it to be around $3500 - $4000 when all of the wiring is added in. That would be the system price, which won't include tools like crimpers or a bench-top power supply.

At some point it is not about the money or the power needs. It about buying cool stuff and building cool things.

 

[luthj]

The performance of this system will far exceed anything of similar size and weight (both solar etc) with a lead pack. It will also allow some pretty cool devices. A brief morning hairdryer usage, cloudy/no solar operation for extended periods. Assuming its treated well, Shade can expect 10 years of service with minimal user intervention. If he decides to switch vehicles it could easily power a small RV or campervan with only a few extra solar panels.

 

[Alloy]

The performance of this system will far exceed anything of similar size and weight (both solar etc) with a lead pack. It will also allow some pretty cool devices. A brief morning hairdryer usage, cloudy/no solar operation for extended periods. Assuming its treated well, Shade can expect 10 years of service with minimal user intervention. If he decides to switch vehicles it could easily power a small RV or campervan with only a few extra solar panels.

I agree. The weight and size are the big advantages. Efficency also when charging by engine/generator but I've not found it so with solar. Mind you our solar is oversized compared to the loads.

I disagree with switching it to another vehicle. When it come time to change there will be new/better tech available.

When looking for a battery pack I only got as far as the battery cost and heating/solar disconnect. I've not ruled out Lithium so I'm wondering which components Shade would use on both FLA and Lithuim.

 

[Alloy]

Thats best, but at minimum all batteries should be enclosed.

If venting for heat/hydrogen isn't nessary then there's no reason to enclose battery(s).

I worked on system that have battery rooms with the batteries sitting on shelves or lined up on the floor. Some have rubber/vinyl boots protecting the terminals others don't.

 

[shade]

$3.5k-$4k, Ouch. What items did you drop to get to FLA at $2k-$2.5? Would the FLA system need a sealed vented battery box?

It's apples to oranges, but the 160Ah LFP battery I'm using was about $1500. Using GC2 LA batteries would cost significantly less, but add a lot of weight to come close to the performance of LFP, and still not really duplicate it.

Thats best, but at minimum all batteries should be enclosed.

At minimum, I'll have a guard installed over the whole system, and I'll probably have some kind of enclosure that'll allow warming the battery.

At some point it is not about the money or the power needs. It about buying cool stuff and building cool things.

There is that.

The performance of this system will far exceed anything of similar size and weight (both solar etc) with a lead pack. It will also allow some pretty cool devices. A brief morning hairdryer usage, cloudy/no solar operation for extended periods. Assuming its treated well, Shade can expect 10 years of service with minimal user intervention. If he decides to switch vehicles it could easily power a small RV or campervan with only a few extra solar panels.

All true. I do construction work that occasionally requires the use of a generator. Those tools could be run off of this system. I'm also considering electric heat for a few gallons of shower water, use of a small microwave oven, and electric heat for stovetop cooking. I doubt I'll be changing vehicles before this battery is used up, but it will be an easy process to move it. It's possible that the tech won't be useful in ten years, but it's pretty flexible gear, so it may still be perfectly fine as long as it can care for a new battery properly.

I agree. The weight and size are the big advantages. Efficency also when charging by engine/generator but I've not found it so with solar. Mind you our solar is oversized compared to the loads.

I disagree with switching it to another vehicle. When it come time to change there will be new/better tech available.

When looking for a battery pack I only got as far as the battery cost and heating/solar disconnect. I've not ruled out Lithium so I'm wondering which components Shade would use on both FLA and Lithuim.

Going FLA wouldn't change much of anything but the battery. Automated disconnects would be beneficial with a SLA battery, but the charge disconnect could be dropped. Other than that, everything else serves a purpose no matter the battery chemistry.

This design is more expensive than some, but it's smart enough to take care of itself with minimal user intervention, it's flexible enough to be used with a variety of battery chemistries, and it's powerful enough to meet whatever I can see myself throwing at it.

 

[Photobug]

I worked on system that have battery rooms with the batteries sitting on shelves or lined up on the floor. Some have rubber/vinyl boots protecting the terminals others don't.

If nothing more a battery should be enclosed in a battery box, if in a vehicle, for protection against battery acid spills. The box and battery should also be strapped down to prevent being overturned.

 

[shade]

If nothing more a battery should be enclosed in a battery box, if in a vehicle, for protection against battery acid spills. The box and battery should also be strapped down to prevent being overturned.

I may be wrong, but I don't believe electrolyte containment is as much of a concern with LFP batteries compared to LA. Still, I'd want a catastrophic failure to cause as little damage as possible, so keeping all of the LFP bits inside a box would be a good idea regardless.

 

[shade]

Believe it or not. Battery room is an enclosure.
Unless the place is managed by a bunch of KCFs...By definition, it contains batteries and support equipment only and not accessible to the ignorant masses.

KCFs?

 

[Photobug]

I may be wrong, but I don't believe electrolyte containment is as much of a concern with LFP batteries compared to LA. Still, I'd want a catastrophic failure to cause as little damage as possible, so keeping all of the LFP bits inside a box would be a good idea regardless.

Sorry I was thinking of FLA as far as needing a battery box, less of an issue with sealed batteries. I think having an LFP secured would be beneficial as it is an expensive piece of hardware, needing protection. Having dropped a socket wrench onto a battery, I now protect the battery terminals from contact.

 

[shade]

Sorry I was thinking of FLA as far as needing a battery box, less of an issue with sealed batteries. I think having an LFP secured would be beneficial as it is an expensive piece of hardware, needing protection. Having dropped a socket wrench onto a battery, I now protect the battery terminals from contact.

Oh, it'll be secured. Even if I didn't care about having a $1500 device bouncing around in my truck, I wouldn't want a 72lb box to hit me in the head, especially one with the potential electrical energy to do that much damage.

Leaving it loose would also lead to internal damage to the battery over time. Firmly fixed is the only way to go, and I'll use terminal covers in addition to an enclosure.

 

[shade]

Looking at fuses, I'm going to save some space with a Blue Sea 300A MRBF terminal fuse on a single terminal fuse block. The max discharge rate of the battery is 320A, so this will function as a last ditch protective measure, with a little headroom.