Lithium query?/

[Bessy765]

Hi all, we have had the following fitted *4 x 175 watt solar panels, Victron mttp 60 amp controller • Victron 2Kva Multi • Victron GX touch control panel • 230 amp upgraded split charge • Victron battery protects for the charge and loads • Victron Cerbo control system • Victron BMV battery shunt • 2 x Transporter Energy batteries We are fortunate to have a large garage at the bottom of our garden to keep the van in. There lies a small problem. As it is in the garage no solar benefit. I have fitted the original 100 watt panel that came with the van on the roof of the garage and fed it via the buzz bar into the van. Obviously at this time of year it does not keep up with the 0.7 amp hour draw this system uses to power the mifi, monitoring,tracker and the parasitic current draw. Would you keep the van permanently on hook up and let the Victron float charge the batteries? Or let it rundown to say 60% soc and then bring it back up to 80% as I understand it is best to not keep these batteries fully charged if you are not using the van.

 

[Otter Spotter]

Skylights in the garage ? Just thinking a little outside the box

 

[suavecarve]

Skylights in the garage ? Just thinking a little outside the box

I thought the same but then the sun (if there is any in the winter) might not get high enough to hit the panel

I would just leave it on 240 but I dont know a lot about these things

 

[Tombola]

Id probably leave it on hook up myself, with a timer switch set to come to charge on once in a while as you see fit

 

[Two on Tour]

let it rundown to say 60% soc and then bring it back up to 80% as I understand it is best to not keep these batteries fully charged if you are not using the van.

That's your best route for your lithium batteries, which is what I'm doing at this time of year with mine.

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[Littlewheels]

Just an aside but shouldn’t your MPPT contoller have more capacit?

 

[paddymcc]

let it rundown to say 60% soc and then bring it back up to 80% as I understand it is best to not keep these batteries fully charged if you are not using the van.

From what I know of lithium that gets my vote. Shouldn't be too difficult if you can monitor it remotely. A timed switch would be a way to do it.

 

[Two on Tour]

Just an aside but shouldn’t your MPPT contoller have more capacit?

Even with optimal conditions a 175 watt panel will produce less than 10 amp.
Victron quotes a max of 9.03 amps for their 175 watt panels, so times 4 is less than 40 amps.

 

[eddie]

On my last camper I installed 3 x 135A Gel batteries and 3 x 130A lead acid batteries to "play" and to prove a point.

On my current camper I have 2 x 120A Lithium batteries, a 120A buck boost B2B and inverter charger with a 80A mains charge and 3 x 175 solar

All Victron and the van is plugged in 24/7 to see what "actually happens"

Been a while now and nothing to report

 

[pete4x4]

I'd turn the 0.7A draw from the monitoring kit off and then the one solar panel will keep pace with the parasitic discharge. Its only down the bottom of the garden so you could just check once a week. It will keep the tracker alive which is the most important and keep a starter battery topped up

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[tonyidle]

On my last camper I installed 3 x 135A Gel batteries and 3 x 130A lead acid batteries to "play" and to prove a point.

On my current camper I have 2 x 120A Lithium batteries, a 120A buck boost B2B and inverter charger with a 80A mains charge and 3 x 175 solar

All Victron and the van is plugged in 27/7 to see what "actually happens"

Been a while now and nothing to report

A successful businessman needs those extra hours

 

[Lenny HB]

The tracker & alarm should be connected to the starter battery I don't see why you need anything else running especially as it's parked on your premises.
Why not fit a cut off switch to the Lithiums, charge them to 80% before storage then switch them off and just keep the starter battery topped up with a trickle charge.

 

[Lenny HB]

On my last camper I installed 3 x 135A Gel batteries and 3 x 130A lead acid batteries to "play" and to prove a point.

On my current camper I have 2 x 120A Lithium batteries, a 120A buck boost B2B and inverter charger with a 80A mains charge and 3 x 175 solar

All Victron and the van is plugged in 27/7 to see what "actually happens"

Been a while now and nothing to report

But it will be many years before you know if it has had an effect on the life of the Lithiums.

 

[Lenny HB]

On my last camper I installed 3 x 135A Gel batteries and 3 x 130A lead acid batteries to "play" and to prove a point.

On my current camper I have 2 x 120A Lithium batteries, a 120A buck boost B2B and inverter charger with a 80A mains charge and 3 x 175 solar

All Victron and the van is plugged in 27/7 to see what "actually happens"

Been a while now and nothing to report

But it will be many years before you know if it has had an effect on the life of the Lithiums.

 

[eddie]

A successful businessman needs those extra hours

Thank you duly corrected 24/7

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[eddie]

But it will be many years before you know if it has had an effect on the life of the Lithiums.

But that is the point really, I don't care if the life of the Lithiums is impacted too much, weighing that up against "faffing" about with storage charging and capacity

 

[the1andonly]

The tracker & alarm should be connected to the starter battery I don't see why you need anything else running especially as it's parked on your premises.
Why not fit a cut off switch to the Lithiums, charge them to 80% before storage then switch them off and just keep the starter battery topped up with a trickle charge.

Totaly agree, and its what i do with mine even though i have set up a BMV712 to control relays based on SOC. KISS
use the external panel to charge the Starter battery and an issolator switch on Li Battery negative.

 

[autorouter]

Since you have a reliable hookup supply, that's the thing to use. Ideally you could let the lithium batteries drain down to 60% or so, then isolate them and connect a 12V power supply to power anything that needs it. You could wire through a relay so that if the mains fails, the battery is used as a backup, preferably triggering an alarm so you would be alerted.

Many chargers can be used in power supply mode, ie without a battery connected, such as the Victron IP22 chargers.

 

[Bessy765]

The tracker and alarm are connected to the starter battery, this in turn is topped up by the leisure’s batteries when not connected to the mains. This van has always had a drain of 0.3 to 0.5from new. This still happens even with habitation electrics turned off.
the cabling for the batteries etc is really heavy duty and would need some size of isolator. The inverter charger is a Victron Multi 2kw with the 80amp charger so not easy to separate. A time would result in bulk charging if on a time clock every time it is turned on?

 

[Old Gibber]

Surely lithium batteries should be stored at 50% charge for longest life?

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[funflair]

The tracker and alarm are connected to the starter battery, this in turn is topped up by the leisure’s batteries when not connected to the mains. This van has always had a drain of 0.3 to 0.5from new. This still happens even with habitation electrics turned off.
the cabling for the batteries etc is really heavy duty and would need some size of isolator. The inverter charger is a Victron Multi 2kw with the 80amp charger so not easy to separate. A time would result in bulk charging if on a time clock every time it is turned on?

I can see your parasitic drain and double it it seems to be common on MORELO and Concorde so I don't even bother trying to trace it, what we have though is an isolator on the LiFePO4 batteries and I just trip this and cut all power to the habitation leaving the starter battery topped up from the habitation via a battery master makes me realise that the alarm and tracker use next to no power as the habitation lithiums hardly drop.

 

[gerry mcg]

With a B2B / and or solar fitted, would it be worth fitting either an appropriately rated 12v breaker like https://www.12voltplanet.co.uk/waterproof-switchable-surface-mounted-circuit-breakers.html or an isolator like such https://www.12voltplanet.co.uk/panel-mount-miniature-battery-isolation-switch-100a.html between the B2B and the lithium leisure battery (and perhaps the solar and lithium leisure battery) in order to be able to ‘control‘ the charging of battery?
any benefit / drawback of either?

 

[eddie]

With a B2B / and or solar fitted, would it be worth fitting either an appropriately rated 12v breaker like https://www.12voltplanet.co.uk/waterproof-switchable-surface-mounted-circuit-breakers.html or an isolator like such https://www.12voltplanet.co.uk/panel-mount-miniature-battery-isolation-switch-100a.html between the B2B and the lithium leisure battery (and perhaps the solar and lithium leisure battery) in order to be able to ‘control‘ the charging of battery?
any benefit / drawback of either?

Only drawback is that it's something else to go wrong

Pull the fuse it you feel its important to disconnect the battery

 

[funflair]

We have a battery disconnect as part of low voltage protection for the LiFePO4 batteries so just use this manually.

 

[Bessy765]

Quite thick cables to get an isolator to fit? and there is one from each battery to the busbar, as I didn’t want them installed in the gas locker, they are fitted under each seat within a Kevlar box for protection.

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