Power Management R27 2017 classic

[ChrisHP]

I found this great presentation about power management https://www.youtube.com/watch?v=Uj_am-ecSt4. I have a few questions I would like help with:

1. How do I find out what my alternator is on our D3? I am looking for the max and idle Amps I can get from the alternator.
2. Is it okay to run the engine at idle a few times a year without damaging it. to allow me to charge the batteries while on Anchor? The solar does keep up with the fridge when sunny but when cloudy I need some more charge and don't want to buy a generator for 4-5 times a year usage. Depending on what the alternator will give me on idle this might not give me enough power hence my question above. I have 2 house AGM batteries with a total of 220Ah in them so will be looking to get around 110Ah back in them if solar hasn't worked and we don't want to move.
3. I want to work out the amps used by some other devices. Do I need to switch off the solar power to allow me to see the accurate draw for those devices and if so how do I do that? I see two fuses next to solar control boxes adjacent to the batteries, would that do it? I could just tarp it.
4. Can the alternator and battery charger work for LITHIUM IRON PHOSPHATE batteries? I don't see any special charging requirements for the batteries on the battery website.
5. Can I replace the 2 house batteries with Lithium batteries and leave the engine and thruster as AGM?
6. Same thing with Lead Carbon batteries can I just replace the house and leave the others?

Cheers
Chris

 

[Andrew Custis]

Hello and thanks for posting. Please see below.

1. The Volvo Penta D3-200HP engine has an alternator size of 180 amps. I have not measured what the output is at different RPM.

2. It is ok to run the engine at idle while at anchor. The biggest concern is to make sure you do run it up to power and make sure you are getting the turbo hot. Idling for extended periods of time can create carbon buildup in the turbo.

3. The only way to get an accurate amp reading is to install an amp monitor or use an amp clamp meter utilizing the last dc grounding coming off of the house batteries. Depending on how it is configured, that might not give you the most accurate reading. If I was really concerned about power managing, I would have an expert re-wire the grounding system and have an amp monitor installed such as the Victron BMV 710.

4. The alternator is not setup to charge lithium ion batteries. You would need a charge controller to handle this. Depending on the solar controller and the type of battery charger, you would need to make sure these are also setup to handle Lithium Ion. I would have an electrician familiar with this setup guide you through this type of installation.

Thank you,

 

[ChrisHP]

Thanks Andrew I really appreciate your response and the speed in getting back to me, cheers.

Do you happen to know the make and model of the alternator and then I can look it up for output at different RPM?

I will make sure if I run idle I will make sure I run it at high RPM to get it hot. Understood about the amp reading and the lithium batteries.

would I be okay with lead carbon batteries on the alternator? And can I use 2 lead carbon and 2 AGM?

 

[ChrisHP]

Thanks CasperCrusiers that's really helpful about checking the volts when on anchor and engine running I will do that and that's really handy to know about looking for the voltage at 13.5 to see if its then charged.

Also thanks about the battery chemistry. Looks like I might have to stick with the 3 year old AGMs then for now and charge using solar / engine then when I replace because they are done I will go with something that gives me more Amp hours. I might get a portable generator if I need to run the engine for too long to get back up to charge. Hopefully to get the 110Ah it won't take too long using your advice and also getting the turbo hot, so I will see how that goes.

 

[knotflying]

Keep in mind that everything depends on how much your batteries have discharged. When you see 14 +/- on the volt meter, you are initially seeing a surface charge which will not last long. You really have to let your engine run a bit to get a deep charge.

 

[ALICE J]

Good instrumentation is the key, Check out Blue Seas Battery monitor or Victron Battery monitor, installed by a qualified electrical guru, then proper decisions can be made on fact, not guesswork. And by all means, read about battery chemistry; charging, discharging, bulk, absorption, float. A lot of info here on TugNuts in back articles, a good education starts from curiosity.