Orion 12/12-18 0r 12/12-30

[simonfraser]

alternator max output 55A
to
Orion
to
200Ah Lithium

if i ran the alternator, at sufficient revs, for a couple of hours would i be over stressing it by using the -30 version ?

set the Orion output V to 14.4 and let the Lithium BMS deal with the charging ?

tnx for your input

 

[neil1967]

I have a 90A alternator and run 2 x 12/12-30 in parallel to charge 400AH of LiFePO4 with no problems. I would have thought a 55A alt could deliver a consistent 30A. Your batteries will charge a lot quicker than Lead Acid as they will take the full 30A until virtually full.

 

[Pete7]

Simon, you could probably use 14v which is 3.5v per cell and will charge to lets say 99%. Just be aware there is a good reason for those large fins on the back. These things get hotter than the sun, so don't put it in a cabinet or under a bunk with no air circulation. Mine is on the outside of the nav seat with a 3" hole behind it. A small computer fan would be a good idea.

Pete

 

[simonfraser]

tnx Pete, fan good point and no prob to install

would the BMS in the battery not deal with the input voltage ?

 

[gregcope]

These get hot and limit output. I would go larger as the smaller one will probably regulate down.

Also worth watching this video on the use of fans with these to keep the output up;

MORE POWER with cooling! | improving the Victron DC-DC Charger

 

[simonfraser]

tnx, i will mount mine on a wall which i can drill a large hole in for a fan and mount the fan at the back
use the load output of my solar controller to control the fan

 

[Pete7]

tnx Pete, fan good point and no prob to install

would the BMS in the battery not deal with the input voltage ?

Actually, despite what the LFP battery manufacturers recommend, there is little to be gained from charging over 3.5v per cell. The amount of energy between this and absolutely full at 3.65v is tiny and could stress the cells if done frequently.

They want you to benefit from every ounce of capacity, you probably want a long and peaceful life out of the batteries.

 

[Pete7]

These get hot and limit output. I would go larger as the smaller one will probably regulate down.

Also worth watching this video on the use of fans with these to keep the output up;

MORE POWER with cooling! | improving the Victron DC-DC Charger

He only has a 55A alternator, so the suggestion from people like Sterling Power, has always been to stick to 50-60% of the max alternator rating, not that you will ever see this.

In practice we see it slowly drop to 26-27A once hot, but that is sufficient for our needs whilst not cooking the alternator.

Pete

 

[simonfraser]

He only has a 55A alternator, so the suggestion from people like Sterling Power, has always been to stick to 50-60% of the max alternator rating, not that you will ever see this.

In practice we see it slowly drop to 26-27A once hot, but that is sufficient for our needs whilst not cooking the alternator.

Pete

tnx, 60% of 55 A = 33 A and will install a fan
and just looking at the output graphs, at 1500 revs, pottering about - often ! not producing 55A

 

[Kelpie]

set the Orion output V to 14.4 and let the Lithium BMS deal with the charging ?

You don't want to be routinely relying on the BMS to control the battery. The system should be set up to charge and discharge within correct limits, and the BMS is there as a failsafe.

 

[simonfraser]

You don't want to be routinely relying on the BMS to control the battery. The system should be set up to charge and discharge within correct limits, and the BMS is there as a failsafe.

tnx - def thread drift now, but i can set the orion to stop at say 14.0V
and use my victron shunt, bluetooth, to ensure i dont run the battery down too far ?

 

[Kelpie]

tnx - def thread drift now, but i can set the orion to stop at say 14.0V
and use my victron shunt, bluetooth, to ensure i dont run the battery down too far ?

Are you only planning on using the Orion when the engine is running? You can wire it up like that, using the remote circuit. Or, as I've done, just manually turn it on and off as part of the engine start/stop procedure.

 

[simonfraser]

Are you only planning on using the Orion when the engine is running? You can wire it up like that, using the remote circuit. Or, as I've done, just manually turn it on and off as part of the engine start/stop procedure.

yes, good point Orion used when engine on
but there is a shore charger too, and if that is plugged it it would charge the lithium 24/7 via the DC to DC ?
the Orion says it is a DC to DC Charger - so surely that woud take care of the lithium battery ??

 

[Kelpie]

You can set the Orion up so that it only starts charging above a set voltage, which will in practice mean it will only kick in when either the engine is running or the shore power is connected

 

[simonfraser]

Tnx Kelpie

Read the manual I recon

S

 

[Pete7]

yes, good point Orion used when engine on
but there is a shore charger too, and if that is plugged it it would charge the lithium 24/7 via the DC to DC ?
the Orion says it is a DC to DC Charger - so surely that woud take care of the lithium battery ??

That is how our shore power charger is wired too. We haven't used it since upgrading the solar, but previously did occasionally when winter sailing and stopping for a few days in a marina. We tended to give the LFP a burst for a few hours of charge and then switch off the SP charger and Orion rather than leave it on 24/7. 50% at dawn? well lets see how solar gets on during the morning and only then top up with SP if it looks like it won't be enough.

The Orion can be switched to power supply mode too btw. Not that I have found a use for this.