Victron Energy: Alternator/Solar Charging - LFP Battery System

[shade]

Since the victron solar controller is connected to the comm bus, do you even need a charge disconnect? You have one for the alternator, and then use a single master disconnect for load/charge as a last layer of defense. Obviously there are reasons to have load/charge disconnects separate, but you are unlikely to regularly run the battery down low enough to benefit from the separation. If you do draw the battery down to disconnect state, you would need to manually enable the disconnect to start charging. This has some value I think, as you will be immediately alerted to any possible issue.

Good question. I'll still have a full manual mechanical master disconnect no matter what. If I don't have a need for house power, I'll leave it manually disconnected with the external BMS running to monitor SoC. I'll have a separate disconnect for the BMS loads, too.

Iirc, I saw VE staff recommend placing a disconnect between the charge controller & battery, but that may have been a different situation. If there's no harm in having both charge inputs run through the same disconnect, that seems a simple way to make sure the battery won't be banging away at 100% SoC.

 

[shade]

Lance tipped me off that I should get on with ordering a 160Ah battery if that was what I wanted, so I did.

Victron Energy LiFePO4 Battery 12,8V/160Ah Smart

Lithium battery 12,8V & 25,6V Smart With integrated cell balancing Can be parallel and series connected Bluetooth app available to monitor cell voltage and temperature 12,8 Volt lithium iron

www.invertersupply.com

I may be charging it with jumper cables, but at least I'll have the powah!

 

[luthj]

Cool. That's a decent price for quality gear.

 

[shade]

I was wondering why the price was lower than the 150Ah model, and it makes sense if they're trying to clear them out. I'd be happy with 100Ah, but the price difference made it easy to go to 160Ah.

 

[shade]

I found this interesting tidbit about using a BatteryProtect for charge disconnect with solar.

Peter Kennedy
3/12/2019
"The MPPT charge controller needs to be able to sense the battery in order to get started first thing in the morning. The Battery Protect lets just enough voltage through that it can sense it and get going. Any other shutoff device shuts it off so completely that the MPPT will not start up by itself in the morning."

That's a good piece of information about the BatteryProtect products. It fits with a warning in the BP manual about not using a BP directly between batteries.
"Caution: uncontrolled reverse current will flow through a Battery Protect if Vout > Vin. Therefore never use a Battery Protect for battery to battery charging."

 

[1leglance]

I found this interesting tidbit about using a BatteryProtect for charge disconnect with solar.

Peter Kennedy
3/12/2019
"The MPPT charge controller needs to be able to sense the battery in order to get started first thing in the morning. The Battery Protect lets just enough voltage through that it can sense it and get going. Any other shutoff device shuts it off so completely that the MPPT will not start up by itself in the morning."

That's a good piece of information about the BatteryProtect products. It fits with a warning in the BP manual about not using a BP directly between batteries.
"Caution: uncontrolled reverse current will flow through a Battery Protect if Vout > Vin. Therefore never use a Battery Protect for battery to battery charging."

So I am still thinking the Buck Boost as the DC DC between the factory alt/battery and the Victron Lith....Does that still seem like a good idea?

 

[shade]

So I am still thinking the Buck Boost as the DC DC between the factory alt/battery and the Victron Lith....Does that still seem like a good idea?

If the price doesn't scare you and the output is enough, I guess so. I may end up going that route, but I'm going to see what DC-DC chargers Victron announces in November.

The Orion-Tr 12/12-30 is another option, but only outputs 30A.

 

[shade]

Lance tipped me off that I should get on with ordering a 160Ah battery if that was what I wanted, so I did.

Victron Energy LiFePO4 Battery 12,8V/160Ah Smart

Lithium battery 12,8V & 25,6V Smart With integrated cell balancing Can be parallel and series connected Bluetooth app available to monitor cell voltage and temperature 12,8 Volt lithium iron

www.invertersupply.com

I may be charging it with jumper cables, but at least I'll have the powah!

Drat!

"We have been informed that this battery has been discontinued and it has been replaced by part # BAT512115610.
The battery is physically a bit smaller and lighter, it also has 10 less Ah of capacity.

Please let us know if you would like us to send the replacement and contact us with your credit card information to cover the difference.
The new model is $1700.00"

 

[1leglance]

Drat!

"We have been informed that this battery has been discontinued and it has been replaced by part # BAT512115610.
The battery is physically a bit smaller and lighter, it also has 10 less Ah of capacity.

Please let us know if you would like us to send the replacement and contact us with your credit card information to cover the difference.
The new model is $1700.00"

call up Northern Arizona Wind and Solar and see if they have any in stock...or someone somewhere might. However I heard that Victron drop ships alot of stuff so all those "in stock" website could be fibbing.

 

[SBDuller]

Drat!

"We have been informed that this battery has been discontinued and it has been replaced by part # BAT512115610.
The battery is physically a bit smaller and lighter, it also has 10 less Ah of capacity.

Please let us know if you would like us to send the replacement and contact us with your credit card information to cover the difference.
The new model is $1700.00"

I was wondering about this transition while viewing your post this AM. I looked at the 100Ah and the 150Ah, states 13Kg difference between 150 and 160Ah. so for that sale price it was more like the new 100Ah, or the new 150Ah model at 1700$ is not that bad....I was thinking the 100Ah model was not that far beyond the BB drop-in...and then all the protection item additions...$$$$

 

[1leglance]

I was on the side of the direct drop in style batteries like Battleborn since they fit in common trays/holders and have all the goodies built in.

But after reading the experiences of people who have the BMS part go out or wanting to know how things work I am coming around to the Victron style system where you can pick the best setup for you.
My current Tacoma / Treehouse camper is a perfect example of me getting 1 part wrong (undersized solar controller) and bottlenecking the entire system.

 

[shade]

call up Northern Arizona Wind and Solar and see if they have any in stock...or someone somewhere might. However I heard that Victron drop ships alot of stuff so all those "in stock" website could be fibbing.

I didn't have time to call Northern Arizona Wind & Sun, but I ordered online and have received an invoice. Not quite there yet, but I hope to find out if they can deliver soon.

The 160Ah is an odd size in the VE line up. I wonder if it was developed for a specific application, and it's no longer needed in the inventory.

 

[spressomon]

Nothing to do with Victron, well except the solar charge controller to keep the battery bank happy when resting in between trips. Just installed a 6500w LFP using Prismatic cells, 4-balancers and a Sterling B2B BB1260 (60A) sourced from ElectricCarParts.com along with a Xantrex Freedom X 3000w inverter in my latest trailer project. Maiden voyage starts tomorrow...no long stretches planned on this trip for parking but eventually will augment with solar for multi-day, same location camps.

 

[Rando]

Another option to consider (at least until Victron comes out with DC-DC charger) would be something like this:



DC-DC charge current is limited to the output of which ever MPPT solar charge controller you are using and the availability of low cost 12->24V boost converters, but this works well for me for 20A of charging with my MPPT 100/20. Total cost for a 20A system is around $40, assuming you have the ACR and MPPT charge controller already.

 

[SBDuller]

Back to the issue of a 100A fuse and a 130A alternator.

Why is the 100A fuse an issue relative to an alternator?
I see the next post indicates a 100A fuse could handle 130A over time.
So if that 100A fuse gives 80A thru the BMS 12/200, is that not a good charge current for 100Ah or 150Ah LFP?