[toyotahiacefan]

Hi everyone,

I am deep diving into the fun topic of house battery charging. Here is my plan:
I am looking for one charger (minimising size and complexity) that can do the following

• Charging from smart alternators

• Charging from Solar

• Charging LiFePO batteries with 100Ah capacity

I think that the battery will last me 2 days (or more) for my fridge and some lights and device charging. I also expect to be driving every 2nd or 3rd day for at least 1-2h. So the strategy I was after is to charge as much as possible from the inverter and only have a small solar setup with 160W.

So far I have found products from the following brands

• Redarc (https://www.rvparts.co.nz/product/redar ... olt-input/)

• Projecta (https://www.smartmarine.co.nz/product/1 ... ry-charger)

• Waveinverter (https://waveinverter.co.nz/shop/battery ... r-charger/)

Keen to hear your thoughts on either:

• Which charger is the "best" or

• whether combination charger are not the way to go because they seem to be so limited in Amps while the alternator could provide more.

[Nut17]

If you prefer to keep to a single device I would recommend future proofing your system by fitting a larger capacity unit
https://au.renogy.com/renogy-50a-dc-dc- ... with-mppt/

The Redarc 20 amp model in your link appears to be a DC - DC battery to battery charger only and does not incorporate the MPPT solar function. If choosing a Redarc unit you would need to opt for this model https://www.redarcelectronics.co.nz/dua ... ry-charger.

The Projecta unit would be fine, but does not have a dedicated LiFePO4 setting, however the Gel setting does suit lithium charging requirements fairly closely.
The unit from Waveinverter looks like good value, but it would be a shame to limit your maximum charge rate to just 20 Amps when your battery would easily accept up to 100 amps.
My preference is definitely to keep to separate charging devices for DC - DC and Solar and with our new rig I will be using a Renogy 60 Amp DC - DC Charger and SRNE Solar controllers.

[Naki585]

Hi.
We have a smart alternator which wasn't charging the house batteries while driving. We fitted a Redarc BCDC 25 which has a MPPT controller as well as a 25amp DC 2 DC charger. Great piece of kit. Couldn't be happier with it. It also acts as a battery isolator, separating the start battery from the house batteries.

Has separate charging profiles for all the common battery types.

The support from Redarc is also excellent.

Cheers

[scubadoo]

Does/will your Hiace actually have a "smart" alternator? Only the very latest models are likely to.
https://www.etrailer.com/question-326099.html etc.

If not my recommendations would vary somewhat.

We converted 4 Hiace hitop lwb vans and people movers over a 25 year period prior to our current setup.

[Paul-Carter]

You need to be sure of what you actually have before you can decide what you want.

A smart alternator is controlled by the vehicles computer instead of being controlled by its own built in regulator. Which by this definition make it a Dumb alternator

What does a smart alternator do?
The smart alternator system allows the vehicle to control the output voltage from the alternator based on vehicle operating conditions to reduce electrical load and in turn mechanical load on the engine by the alternator, this renders it unsuccessful at charging a secondary battery system to a usable level.

I can personally vouch for this product and the backup and advice he provided. This is fitted to a second alternator that takes care of house batteries only.
https://www.smartregulator.co.nz/

[toyotahiacefan]

Thanks everyone so far. Actually, just from reading the product specs, the Redarc units https://www.redarcelectronics.co.nz/dua ... ry-charger or https://www.redarcelectronics.co.nz/dua ... ry-charger or
https://www.redarcelectronics.co.nz/dua ... ry-charger
seem to be quite good value in combination devices.

The Renogy device (https://au.renogy.com/renogy-50a-dc-dc- ... with-mppt/) is called 50A but can (apparently) only do max 25A from the inverter and max 25A from solar. So only when you have full input from both you will reach the 50A, so it seems.

I could not find out whether something similar applies for the Redarc device (https://www.redarcelectronics.co.nz/dua ... ry-charger). Also on the topic of Redarc, somewhere on this forum I read that you cannot select individual voltages (only the LiIon profile) on the Redarc units. Apparently this produces problems with some (BMS-built-in) Lithium batteries. Is that an edge case or really something important to consider?

Regarding the smart alternator, I will measure that one to find out.

[mattn]

RENOGY 60A DC TO DC BATTERY CHARGER combine with a 20AMP Solar controller will do a better job than the Redac for half the price. Any particular reason you have an aversion to separate controllers? Lithium batteries don't need expensive 'smart' controllers. They need 13.8V and current, the more the better. Replacing Amps capacity with intelligence is, how do you put it, not smart.

With lithium batteries, 20AMP chargers are toys, Lead Acid batteries around 100AH themselves can't take much more than 20AMP, so there is little point installing more charge capacity. Lithium 100AH batteries will take a lot more, typically 1C so 100A for a 100AH battery . This means putting in the biggest charger the battery can make use of makes the most sense if you can afford it. If you can charge at 100AMP, your drive time to fully charged is reduced to 1/5 compared to 20AMP. A realistic size might be a 60Amp Dc-DC charger if you alternator can handle it (upgrade the alternator). Many times you won't need it, but if your battery is flat, and you have 1 hour to you next destination, what would you rather do - drive for an hour of take the scenic, 3 hour road trip?

There little point paying the premium for a Lithium battery if you only going to be able to give it 20AMP of 25AMP to charge it. The problem I see with you proposed use case is the 100AH battery could be needing 75-85AH to get it charged. With a 20 or 25AMP charger, your going to need 4 hours of driving time.

[Neddy]

I reckon that your proposed setup places too much emphasis on alternator-based battery charging and not enough on Solar power.
It would be good if you could install more solar than the single 160 Watt panel proposed. Is there any spare space available on your rooftop? 400 Watts can be fitted into 1480mm x 1360mm, even 600 Watts takes just 1480 x 2040mm. Panels cost around $1 a watt. Usually, people simply install as much solar power as they can fit. (It's that good!)

You have very modest electrical requirements and, as I see it, have no need for expensive "high current" gear such as a DC-DC charger (or a Lithium battery, come to that!)

A $138 dual-sensing VSR would automatically enable House battery charging from the alternator as well as Starter battery charging from the solar panels. It also has the effect of adding capacity to your House battery. This is a very common solution and is the setup I have got.

In my opinion, an adequate solar setup is way more important than relying on engine hours to meet your electrical needs.

You find somewhere really nice and would like to stay there for a week - but your House battery is getting depleted after just a few days. You dare not destroy your expensive Lithium battery by flattening it - so what are you going to do? Move on? Go for a pointless drive? Sit with the engine idling for hours? "Invest" in a noisy generator?