New system needed

[Sooz52]

Have you measured the space you have for batteries?thats where you need to start and do you have an inverter to charge your laptop

Hi, yes yes and yes ?

 

[Sooz52]

The idea is not to exceed the voltage and current limits. For a 100/50 regulator, 100 is the voltage input from the panels, and 50 is the current (amps) output to the batteries.

If the panels are in parallel - as usual on motorhomes - the voltage will be the same as a single panel voltage of 20 to 40V, so voltage is never a problem.

To work out the current, take the nominal panel watts and divide by the BATTERY voltage, then take about 70 or 80% of this if in Europe with the panel flat on the roof.

Example: three 120W panels: 360/12 = 30 amps, 80% of that is 24 amps. So if the choice is a 100/20 and a 100/30, it would have to be the 100/30.

Don't be misled by the 'max power current = 5.45A'. That's the PANEL output current, at the max power voltage of 22.0V. When the regulator steps down the voltage to feed the battery, it steps up the current to keep the power (volts x amps) the same.

So a 100/30 regulator can manage about 400W of panel if feeding a 12V battery, but can manage 4 x 400 = 1600W of panel if feeding a 48V battery. That's one reason for using higher battery voltage on a house installation, where the only thing connected to the battery output is the inverter.

Thanks, really helpful. It looks like I need 100/50 with the set up I’m planning

 

[Sooz52]

Ditch the gel and get half of that capacity in lfp. You don’t need bmv 712, a 702 will suffice.

It’s just sooooo expensive!

 

[Raul]

Look at ultramax 480 quid for 100ah, bms inside. What’s not to like? You can have as many as you like in paralel. They based in London, UK vat invoice, ebay shop free delivery mainland uk. Still expensive? I don’t think so.

 

[Sooz52]

Look at ultramax 480 quid for 100ah, bms inside. What’s not to like? You can have as many as you like in paralel. They based in London, UK vat invoice, ebay shop free delivery mainland uk. Still expensive? I don’t think so.

I am waiting for a call back from them, thanks ? (although I am in Spain)

^{_{Subscribers  do not see these advertisements}}

 

[Sooz52]

Ultramax 200Ah ordered!! Woohoo. I note that they include a charger so an MPPT isn’t strictly necessary... I’ll leave my exiting MPPT on the old panels which will look after the car battery and also plug into the new battery. Do I really need another MPPT (victron 100/50) to manage my power effectively?

 

[Raul]

Congratulations, the charger that comes with it, if is a 20a charger it stops at 14.4v if is a 10a charger it stops at 14.6v to high. Note, these chargers are mains plug in. From the solar you still need a configurable MPTT or PWM. I do not use the main charger except for the first charge, there after I don’t charge to full never. I stop charge at 13.70- 13.80v max. On ehu, I use the victron inverter charger to charge from mains, limited to 0,2C rate. On your 200ah you can charge up to 40a rate, to keep it sweet. I got two of those in the picture, paralleled with a 100a blue sea cube fuse on terminal and 35mm cables.

 

[Sooz52]

It is with a large touch of embarrassment I post this. I was going through the fuses checking why my wardrobe and above passenger seat lights aren’t working and found that the fuse labelled “solar” had blown. Can anyone tell me what function this fuse serves in the solar set up? Possibly I’ve only been getting charge from the alternator... Separate tests in 2 workshops have told me my batteries are pooped anyway so the new lithium is going to be fab.

 

[Rodneyplonker]

Any fuse in the system is a safety device against damage to the system. For instance, if working on your batteries or disconnecting them. I’m sure damage to your regulator and even the panels could occur if the charge from the panels was not disconnected when removing or disconnecting the batteries. your system should be checked to find the cause of a blown fuse...if not immediately obvious. Obviously, if not running the engine your batteries would soon flatten if no current getting to them because of blown fuse.
Members with greater knowledge will expand on this, I’m sure.

 

[autorouter]

Can anyone tell me what function this fuse serves in the solar set up?

A fuse is a safety device. Any wire connected to a battery needs to have a fuse. If no fuse is wired in, then if the metal part of the wire touches the metalwork the battery is shorted, and the wire heats up until it is glowing red-hot and can easily start a fire. To avoid that, a fuse is wired in so that if the wire touches the metalwork, the fuse blows instead, and cuts off the battery current.

In your solar circuits, it depends on whether the fuse is between the solar controller and the battery, or between the solar controller and the panels.

On the battery side it is an essential safety device. On the panel side it is not really necessary because shorting the solar panels does not lead to excessive current like when you short a battery. But sometimes they are fitted anyway, and can be handy if for some reason you want to disconnect the panels from the controller.

You could try just replacing the fuse to see if the battery starts charging. If the new fuse blows there might be a wiring fault.

^{_{Subscribers  do not see these advertisements}}

 

[Sooz52]

A fuse is a safety device. Any wire connected to a battery needs to have a fuse. If no fuse is wired in, then if the metal part of the wire touches the metalwork the battery is shorted, and the wire heats up until it is glowing red-hot and can easily start a fire. To avoid that, a fuse is wired in so that if the wire touches the metalwork, the fuse blows instead, and cuts off the battery current.

In your solar circuits, it depends on whether the fuse is between the solar controller and the battery, or between the solar controller and the panels.

On the battery side it is an essential safety device. On the panel side it is not really necessary because shorting the solar panels does not lead to excessive current like when you short a battery. But sometimes they are fitted anyway, and can be handy if for some reason you want to disconnect the panels from the controller.

You could try just replacing the fuse to see if the battery starts charging. If the new fuse blows there might be a wiring fault.

Thanks... though I know what a fuse does... the question was intended to be - in which part of the circuit does this fuse sit.

 

[autorouter]

Thanks... though I know what a fuse does... the question was intended to be - in which part of the circuit does this fuse sit.

If the fuse has blown it's almost certainly in the part between the controller output and the battery.

 

[romany]

I have to say totally confused by all this power people seem to be using I mainly FLT and I have 120w panel which is getting old now and two 110 amp LA's and 85amp vehicle batt I use lap top phones and TV all charged off of leisure system LED lighting and camp here as well as abroad late and early in the season and never once has my system dropped below good ( my system reads very good, good, low, then red light comes on) never seen the other two am I very low usage which I doubt or our people just over worried about power and Hording it

 

[Richard n Ann]

I have to say totally confused by all this power people seem to be using I mainly FLT and I have 120w panel which is getting old now and two 110 amp LA's and 85amp vehicle batt I use lap top phones and TV all charged off of leisure system LED lighting and camp here as well as abroad late and early in the season and never once has my system dropped below good ( my system reads very good, good, low, then red light comes on) never seen the other two am I very low usage which I doubt or our people just over worried about power and Hording it

Agree, we got 150w solar, plenty of power ??

 

[ianp]

Just to re open this thread, can I ask (principally Raul & Autorouter) how would the fitting of Lithium Batteries mesh with an EBL99 as regards charging etc? In addition am I right in thinking that Lithium batteries don't give off any gases that are either explosive or noxious in any way?

^{_{Subscribers  do not see these advertisements}}

 

[autorouter]

Just to re open this thread, can I ask (principally Raul & Autorouter) how would the fitting of Lithium Batteries mesh with an EBL99 as regards charging etc? In addition am I right in thinking that Lithium batteries don't give off any gases that are either explosive or noxious in any way?

Second question first. There are various kinds of Lithium battery, and all are sealed and don't give off noxious gases during normal use. The batteries usually used for motorhomes are Lithium Iron Phosphate (LiFePO4). All Lithium batteries are 'lithium-ion', but only this type is 'lithium iron', easy to get confused. LiFePO4 batteries are reasonably safe, given that they are a powerful energy store. They don't catch fire if punctured, like other types of lithium battery.

Next question, the EBL99. The answer depends on what you want to do. The EBL99 is a multipurpose control box, built for a specific job. It contains a mains charger, which is 18 amps, and does not have a lithium setting.

There is a socket to attach a second charger. You could get a lithium compatible charger and attach that, if you pull out the fuse for the internal mains charger. The socket will not take more than 18 amps, so this method is only suitable if you are leaving everything as it is, but just changing the battery from lead-acid to lithium.

There is the question of charging from the alternator. For various reasons, charging a lithium battery by split charge relay from the alternator is not a great idea. Best to get a B2B with lithium compatibility, and fit it in the starter battery connection at the back of the EBL.

If the intention is to upgrade, to add some heavy 12V loads like an inverter, then it's probably best to go direct to the battery with the mains charger, B2B and any new heavy loads. Let the EBL just supply the loads it is built to do - lights, pump, heater/water heater control etc.

 

[ianp]

Many thanks for the informative reply Autorouter, its given me a fair bit to mull over as I intend to uprate the van later this year and the idea of Lithium appeals. I may have to contact you again later on in the year for a little clarity as the extent of the change / uprating isn't as yet fully decided! Again many thanks!