Upgrading to Lithium 100 Amp Hr Batteries

[Out West]

I have a 2006 W Journey. I do realize i need to change the converter because of the 14.7 voltage requirements. I plan to install three of them and am having a hard time figuring out what amperage charger I can use with the coach wiring. The charger seem to run 30,45,60 and 80 amps. I would like to use the highest to minimize the charging time without causing problems with the coach wiring or premature battery burn out.
Any help would be appreciated.
It took me a while to figure out what I didn't know.


Thanks, Wayne

[creativepart]

I don’t know the answer to your question but, I have seen others mention that they are using 60 and even 80 amps. But the question of wire size I’ve not seen discussed. It probably depends also on how far the charger is from the batteries.

What do you plan to do about alternator charging?

[Out West]

I've been told in some places it's under the bed and others under the fridge. I'm still looking it really shouldn't be that hard to find.
As far as the alternator goes it has to be putting out around 13.7 right for the lead acid batteries I'm pretty sure the 14.7 would cook them.

Since you asked there must be options I'm unaware of.
Wayne

[creativepart]

Originally Posted by Out West

As far as the alternator goes it has to be putting out around 13.7 right for the lead acid batteries I'm pretty sure the 14.7 would cook them.

Since you asked there must be options I'm unaware of.
Wayne

Yes, you shouldn’t just ignore it. You should at least research it and decide what you want to do.

1. Do nothing
2. Add a battery isolator
3. Add a DC to DC charger

The batteries are capable of demanding so many amps from the alternator that you can burn up the alternator.

Battleborn sells an isolator. Victron sells a DC to DC charger.

When you do your research you’ll find many that say don’t bother doing anything special.

So, it’s up to you. But you should look into it.

[powercat_ras]

The wire running from your current converter to the batteries is sized to handle 45 amps. You could just replace your current converter in the current location with the Progressive Dynamics PD9145ALV 45-AMP which is designed for Lithium Batteries. It has a maximum amp output of 45 just like your current one.

The way alternators work, you don't need to worry about burning up the alternator from the new batteries. The output voltage of the alternator drops with increasing current. You won't burn up the alternator for the same reason that running an alternator into a almost discharged lead acid battery does not burn it up.

[moabdds]

I recently upgraded to 3 Battle Born lithium batteries, and Battle Born recommended either their recommended BIM (Battery Isolation Monitor) or a DC to DC charger. I opted for the BIM, which I installed myself. It was difficult because of access, but I got it in and it seems to work fine. I chose the BIM because I was also putting in a Victron 3000w inverter, which has a 120 amp charger built in.

[jerichorick]

Originally Posted by Out West

I have a 2006 W Journey. I do realize i need to change the converter because of the 14.7 voltage requirements. I plan to install three of them and am having a hard time figuring out what amperage charger I can use with the coach wiring. The charger seem to run 30,45,60 and 80 amps. I would like to use the highest to minimize the charging time without causing problems with the coach wiring or premature battery burn out.
Any help would be appreciated.
It took me a while to figure out what I didn't know.


Thanks, Wayne

Wayne, I am about to do a upgrade myself. One question I have about new your batteries. Are they rated "Plug & Play"?? If so, they each have a built in BMS (battery management system) speced to protect the battery.

In my case I am building my battery from ebay Nissan Leaf packs. Big challenge. Waiting for parts to come in. Plan on using my existing inverter. I have the ability to tweak it.

[JoeC]

You can safely charge, most if not all, lithium batteries at 50C which is 50% or 1/2 of the ah rating in charge amps. For you that would be 50 amps, 150 amps for 3 100ah batteries connected in parallel. Don't worry about charging your batteries too fast. It's just as important to have good, clean high quality DC power to charge them with. Most quality name-brand products should be sufficient for this. That leads us to the engine alternator charging system where many choose to use a DC-DC power supply, that is designed to handle lithium battery charging, between the alternator and the lithium batteries.

My Ford E450 Triton V10 standard alternator charging system has been doing a decent job charging my lithium batteries for the past 9 months but I manually disable it when the batteries are near or at full charge. I'm looking into converting the "battery boost" switch from a momentary switch to a 2-position switch, where I will be able to de-energize the interconnect solenoid from the dash. I monitor my electrical system closely using the Victron BMV-712 remote iPhone app.

[creativepart]

Originally Posted by moabdds

I chose the BIM because I was also putting in a Victron 3000w inverter, which has a 120 amp charger built in.

The DC to DC charger takes power from the alternator and controls the voltage output to better suit the charging needs of your LiPo batteries. It has nothing to do with the 110v A/C charger inside your Victron inverter that charges your batteries when on shore power or generator.

These are two totally different chargers that serve two totally different purposes.

[JoeC]

[QUOTE=JoeC;3857488]You can safely charge, most if not all, lithium batteries at 50C which is 50% or 1/2 of the ah rating in charge amps.

Sorry, that should be .5C, not 50C charge rate, which is 50% or 1/2 of the ah rating in charge amps.