Thursday, April 8, 2021

Alternator & Lithium Battery Charging


Standard alternator vs Balmar Marine alternator with and without Victron current limiting devices.  The original source for this video was from one of my RV blogs.  This is presented as a planning tool for those considering converting to lithium batteries in their RV.  Be aware that changes to your system will be required to make the conversion. 


 I know this video is from Victron and thus it is not unbiased, but I found it interesting in that it described some types of charging that are dangerous for alternators when connected to Lithium batteries. And while the Victron DC-DC charger is mentioned it is not the center of the tests.

 Typical Lead Acid batteries (SLA) tend to have their internal resistance rise tremendously as they approach a full state of charge - which means they accept less and less current, and hence not overdrawing the engine alternator.

But LiFePO4 batteries do not, and will accept most of the current given them when charging - which is as you noted - can be very hard on stock alternators trying to pump out all that these batteries are willing to accept. On one hand this is one of the great benefits of Lithium batteries - they charge up must faster - especially beneficial when charging from a solar system or when running a generator. But as noted if and when connected to the engine alternator for charging it can over tax it.

This is why there are DC-DC chargers made. These devices specifically limit how much amperage charge is given to the house batteries - both by design as well as by switchable parameters in the unit itself. These are made in different amp ratings. I am considering a 20 or 40 amp Renogy model -
Amazon but there are many of these types of devices from other manufacturers-

These DC-DC chargers not only limit the amperage draw on your engine alternator, but they can also be set for your specific house battery chemistry, set to differing charging modes, and can be set to a maximum voltage, at which point it greatly reduces the amount of charge coming through it into your batteries - making life much easier on the alternator.

Someone mentioned that the downside of these is that they only transmit power 1 way - which is true - as they are designed to only allow current flow from the engine into the batteries. But you can still use the dash battery connect switch (found on many RVs) which connects the house batteries to the engine battery momentarily in order for the house batteries to assist a discharged engine battery (theoretically from not being used) - it depends on how the DC-DC charger is wired in. The dash switch utilizes a solenoid to connect the 2 battery systems due to the high amounts of current the engine starter draws. But properly wired the DC-DC charger should never be connected through that solenoid at all. They have their own on-off remote switching and when off they are automatically isolated from the solenoid connection switching.

BTW - I would like to have 400Ah of Lithium batteries. They would make all the difference in using my RV as I add a solar system, I hardly would have to use the generator any more, and they would really enabled us to boondock much more enjoyably than fighting with my old SLA batteries. Also saved several hundred lbs of battery weight too.

So it is good to recognize a potential problem when using Lithium batteries which may be connected directly to the engine alternator - possibly overly stressing it. But there are simple solutions, and the benefits of Lithium batteries are many.

Friday, April 2, 2021

Rooftop airconditioner improvement

 Rooftop airconditioners are renown for having  problematic input/output airflow issues.  Check out this quick youtube for ideas on improving your efficiency:

 Here is another link from a Winnebago Forum.   

A quote from the forum: QUOTE" We have a NewAir portable ac. We only have one AC and it was very loud. There’s a new accessory you can buy to quiet it down and enhance performance but it’s a bit expensive in my opinion we made one ourselves. There are some YouTube video about it that might help. There’s also a great write up here." ENDQUOTE.


Tuesday, September 1, 2020

Camping in Michigan

 We loved to boat on Lake Michigan and now we love camping there.  However, it is not always easy to find a camp site and even harder to find an open spot.  If you use the link below this will assist you tremendously.

Michigan Campsites et al 

How to use a portable waste water "Tote" tank


How to use a portable waste water "Tote" tank. If you want to stay at your primitive campsite more than 3 days± then you need one of these pesky, somewhat smelly things. 

 This is also known as a “Blue Boy”, obviously because of the color, they come in different colors from different manufacturers.

Remember the cardinal rule - do not overfill. They hold about 25 gallons of blackwater. Chose one with big, wide wheels of convert yours to big wide wheels. They hold about 25 gallons US.

Thursday, October 24, 2019

Wow 0 Minie - Winnie New Roof

This is a complete roof (cabin top) installation.  This should give you some ideas for your RV or boat.  Anyway, I thought it was pretty cool so I wanted to try and insert the video.

"The video used to be here but I was told to remove it for copyright reasons"

Thursday, July 18, 2019

Plumbing with PEX

This is not an original thing but it acts as a library for myself and for others.  I had this installed in my Youngsun 35 and wished I had put  it in my Irwin 43.  This vLog is a good concise tutorial on using fittings with PEX.  I hope you enjoy it:

Friday, March 15, 2019

Allstar Amatuer Radio System

This is one of many systems to implement an Allstar node.  This one uses an Alinco radio and it is a reliable system as long as you use low power mode and a fan on the power amplifier portion.  I have one operational and have used it for years.

The interface board is a RIM and along with a RaspberryPi and Alinco Radio you can have a system up and going in an hour or two.  Follow THIS LINK to get the general idea.

To get an idea of what Allstar is and how to build one go to Hamvoip website.  However, you will need to have an Amateur Radio license to legally operate this system and to get  a node number.  If you would wish to make a private node for only your self that is possible using a commercial radio licensed frequency or GMRS but check the rules for legal use of these frequencies.