Lithium upgrade consternation

[HereAndThere]

Hello,

It's time to replace the dual 6v batteries. Finding out the heater won't work at night because the batteries were too low was a wake-up call.

I've read posts over the years of those who have done the upgrade, and with the cost of lipo being so high had decided to stick with lead acid... however with SOK batteries being reasonable and a decent lead acid/agm costing 50% of the price I'm looking again at LIPO. I have 1 solar panel and a 200w portable kit and a 1500w inverter, batteries are inside trailer.

There are a few questions I have though.

I've read that when using lipo, the 12v system can run at a higher voltage (from the higher charging profile I'm guessing) and that this may damage some of the 12v systems. I've already replaced some of the interior cabin lights due to their flickering which per my reading was due to their not supporting the 13+ V operation when the batteries are being charged. The main concern being the fridge and furnace, the fridge is a 3 way Dometic DM2663LBX, I don't know the furnace model. The water heater is dual propane/electric and we also have a Dometic AC. Should I be concerned about lipo damaging any of the existing hardware?

I know my WFCO WF-8955PEC and Gopower GP-PVWM-30 don't have lithium charge profiles and from what I read this will likely mean lithium batteries won't charge to 100%, which I'm okay with. Eventually I'll install a GP-PVWM-30-UL and a PD4655V to gain lithium support (unless there are better drop in replacements). Is using lithium batteries with the existing charge controllers going to damage the batteries?

I've also read that it's best to store lithium batteries at 50%. I'm not sure how I'd know they were at 50% and is there a solar charge controller or other that allows you to set it to 50%? What can be done to ensure a 50% storage charge?

Spending $200 on cheap lead acid is okay, $500 on quality lead acid is bothersome when compared to a single SOK 100ah for $600 since the usable capacity for both is about the same. I'd likely be installing 2x SOK batteries so $1200, but then it's a real upgrade. Adding the new charge controllers at the same time would be problematic if a harmonious marriage is desired, being as it is that she wants me to sell the trailer anyway...

If my existing hardware can survive and I won't damage the lipo batteries using the existing chargers then I'd like to take the plunge, otherwise it will be cheap 6v until I can save up or justify all the other hardware required.

Thank you!

[rubicon327]

Threads like this may inform your decision
https://www.escapeforum.org/forums/f...tml#post439125

[HereAndThere]

Thanks rubicon, yes I had read that one already. For now I'll just go the lead acid route until I can upgrade the whole system. There's excitement when one "must" buy something new for the trailer, calmer minds prevailed this time...

[HABBERDABBER]

You mentioned $200 for new lead acid 6V's. Costco does sell a $100+, 6V version for golf cart & other use. Caution, as although they are Interstate brand, and Costco does have good return policies, these are not the top model of 6V Deep Discharge that Interstate sells. They have a version about $220 EACH, with more robust construction and materials.
Trojan Batteries is another respected brand for 6V deep discharge FLA, at the same price as the premium Interstate 6V's.

YMMV

[CE Vogel]

It is true lithium batteries run at a higher voltage than lead acid or AGM batteries. My Renogy batteries charge at 14.4V and discharge at 13.6V to 13.4V. I have had zero problems with the 12V items in my trailer, including the three Maxxfans that other people have had issues with.
You can charge lithium batteries with a non-lithium converter, but it will not fully charge them as others have said. Make sure to disable the equalizing function, as the 15V equalize voltage will cause the lithium BMS protection circuit to disconnect. If your converter has an AGM setting, use that as it disables the equalizing function.
One thing to consider is the higher voltage of the lithium batteries mean your tow vehicle will NOT charge batteries, and the lithium batteries will actually discharge into your tow vehicle battery. You can disconnect the tow vehicle charge wire, or better, install a DC to DC converter in the charge line. The DC to DC converter will also limit the current drawn from the tow vehicle, protecting the tow vehicle wiring and 7-pin connector.

[rubicon327]

Originally Posted by CE Vogel

It is true lithium batteries run at a higher voltage than lead acid or AGM batteries. My Renogy batteries charge at 14.4V and discharge at 13.6V to 13.4V. I have had zero problems with the 12V items in my trailer, including the three Maxxfans that other people have had issues with.
You can charge lithium batteries with a non-lithium converter, but it will not fully charge them as others have said. Make sure to disable the equalizing function, as the 15V equalize voltage will cause the lithium BMS protection circuit to disconnect. If your converter has an AGM setting, use that as it disables the equalizing function.
One thing to consider is the higher voltage of the lithium batteries mean your tow vehicle will NOT charge batteries, and the lithium batteries will actually discharge into your tow vehicle battery. You can disconnect the tow vehicle charge wire, or better, install a DC to DC converter in the charge line. The DC to DC converter will also limit the current drawn from the tow vehicle, protecting the tow vehicle wiring and 7-pin connector.

Great summary. It was never definitive but I believe some of the problems with 12V items were with solar chargers being set up to equalize the flooded lead acid Interstate GC2's at 15.6V. We never had a problem at 14.4 with the standard WFCO-8955 converter/charger. We didn't have solar. Without equalization I guess we would have reduced their life but I don't know because we went to lithium and the GC2's now have a second life in a golf cart up near Lake Erie. We also charge our Bestgo 400AH lithium at 14.4V via a Xantrex Freedom XC inverter/charger and don't have any issues with the 12V items.

[Perry Butler]

Originally Posted by CE Vogel

It is true lithium batteries run at a higher voltage than lead acid or AGM batteries. My Renogy batteries charge at 14.4V and discharge at 13.6V to 13.4V. I have had zero problems with the 12V items in my trailer, including the three Maxxfans that other people have had issues with.

After numerous green light issues, when the fan stops working, with the MaxxFan in our 5.0 it finally quit running after rebooting the board. We run the fan on the lowest setting 24/7. We were charging our SiO2 batteries at 14.5v for 1 year when I purchased a new board and was promised the new board would handle the voltage. A month after install the green light started coming on again. I installed a voltage regulator and the green light issues went away.

Some of us definitely have had issues that were verified by Maxxair. They made a change in acceptable voltage in the newer boards, that seem to work for some, but not with others. A voltage regulator fixed ours. We sold our 5.0 last December though.

Enjoy,

Perry

[HereAndThere]

Thanks CE Vogel, I hadn't read about the batteries discharging into the tow vehicle, I'll add the DC to DC connector to the list of items to add. Is this the same thing as a DC to DC charger like the Victron Energy Orion-Tr Smart 12/12?

It seems per Perry that the higher voltage still may be an issue for some. I was originally thinking of moving to a 24V battery then putting a Victron Energy Orion 24/12-Volt 70 amp DC-DC Converter between the battery and the 12V power distributor so that the 12V would be regulated as close to 13V as possible. Is this a silly idea for such a small system?

[oldwave]

Originally Posted by HereAndThere

Thanks CE Vogel, I hadn't read about the batteries discharging into the tow vehicle. Do you know if this could negatively affect the tow vehicle?

The issue would be if you leave it hooked up after the vehicle is off. A victron dc to dc detects the alternator charging and shuts off the device after the alternator is off. This isolates the batteries. I have the small 18 amp version because I did not want to upgrade to a dedicated charge wire from the vehicle battery. Worked well across the country in January.

[CE Vogel]

Originally Posted by HereAndThere

Thanks CE Vogel, I hadn't read about the batteries discharging into the tow vehicle, I'll add the DC to DC connector to the list of items to add. Is this the same thing as a DC to DC charger like the Victron Energy Orion-Tr Smart 12/12?

It seems per Perry that the higher voltage still may be an issue for some. I was originally thinking of moving to a 24V battery then putting a Victron Energy Orion 24/12-Volt 70 amp DC-DC Converter between the battery and the 12V power distributor so that the 12V would be regulated as close to 13V as possible. Is this a silly idea for such a small system?

My reply got wordy, so apologies in advance.
The Victron Energy Orion-Tr Smart 12/12-18 is a good choice. Make sure you get the ‘smart’ version, as it automatically shuts off when the tow vehicle turns off. I use a Redarc BCDC1225D because it is both a DC-DC charge converter and a MPPT solar charge controller. It is smart in that it prioritizes solar charge over tow vehicle charge (saving some fuel), and also automatically shuts off tow vehicle charge when the tow vehicle is turned off.
Be aware the current drawn from the tow vehicle is always greater than the current delivered to lithium trailer batteries through a DC-DC converter due to Ohm’s Law. My Redarc delivers 25 amps at 14.4 volts (360 watts) to the lithium batteries. My tow vehicle charges at 13.8 volts, but due to wiring losses, there is about 12.5 volts at the 7-pin connector. Therefore, my tow vehicle must deliver 29 amps at 12.5 volts to provide 360 watts. The 18 amp Victron should work with most factory tow vehicle wiring. I installed a heavy charge wire to handle the heavy current load in my tow vehicle.
Ask ten people about the value of 24V systems, and you’ll get ten answers. Personally, I don’t see value of 24V until the solar panels exceed 600 watts, as that requires heavy, costly, 50 amp wiring. For smaller systems, the voltage conversion inefficiencies likely exceed the wiring efficiencies gained. Not to mention the cost and complexity of the added components.
You will find that lithium battery voltages are much better controlled than lead acid or AGM batteries. My Renogy batteries have two voltages: 14.4 charge, 13.5 discharge until they suddenly shut off when over-discharged. Lead acid could be anywhere between 10 and 14 volts, with periodic 15+ volt equalizing periods. Some people had trouble with older MaaxFan units, but newer units, including my three 2020 fans, don’t have the problem. I haven’t heard of any other 12V appliances generically having problems when attached to lithium batteries. In any case, lithium batteries never expose 12V appliances to the 15+ volts lead acid batteries periodically imposed.
The consistent discharge voltage of lithium batteries make traditional battery monitors useless. This is why many people install the Victron charge monitoring system, it actually measures power in and power out and calculates battery state of charge. Without that, you will be happily using your batteries until they suddenly shut off.
Keep your upgrade simple. Install 1 or 2 lithium batteries, install a DC-DC converter, and call it good for now. Next, install the Victron charge monitor. Later, you can upgrade your power converter and solar charge controller. For now, don’t worry what level you are storing lithium batteries, they are quite forgiving as long as they aren’t completely discharged. Store your trailer with the batteries disconnected and you’ll be fine.

[rubicon327]

Originally Posted by HereAndThere

It seems per Perry that the higher voltage still may be an issue for some. I was originally thinking of moving to a 24V battery then putting a Victron Energy Orion 24/12-Volt 70 amp DC-DC Converter between the battery and the 12V power distributor so that the 12V would be regulated as close to 13V as possible. Is this a silly idea for such a small system?

24V is probably overkill unless you have high DC amp loads serving a large inverter that is quite far from the battery. This would allow you to downsize the conductors. Otherwise I would stick with 12V for simplicity. If you stay 12V the following is probably moot but keep in mind that the typical stock Escape DC design has a “two-way” conductor that can send current to the loads from battery or send current from the converter/charger to the battery. You cannot simply add a Victron DC-DC charger on this DC line as it is a one-way device with distinct input and output. In other words you cannot place it between a battery and another charging source (i.e. WFCO converter/charger or tow vehicle) on the other side that would then be unable to charge your battery. That would put a charging source on the output side of the Victron. It is possible if you are designed with a combination inverter/charger/transfer switch like the Xantrex Freedom XC direct to the battery with a “one-way” dedicated DC conductor from the battery to the 12V distribution board (abandoned WFCO converter/charger) but you would also need to ensure your DC-DC converter from tow vehicle is hooked up direct to the battery. This way it is not opposing this DC-DC converter on the main line. I hope this makes sense. I recommend drawing out a schematic and posting for input from the members with electrical experience before committing to any major redesign. That’s what I did and went through several iterations before getting it right.

[oldwave]

Originally Posted by rubicon327

24V is probably overkill unless you have high DC amp loads serving a large inverter that is quite far from the battery. This would allow you to downsize the conductors. Otherwise I would stick with 12V for simplicity. If you stay 12V the following is probably moot but keep in mind that the typical stock Escape DC design has a “two-way” conductor that can send current to the loads from battery or send current from the converter/charger to the battery. You cannot simply add a Victron DC-DC charger on this DC line as it is a one-way device with distinct input and output. In other words you cannot place it between a battery and another charging source (i.e. WFCO converter/charger or tow vehicle) on the other side that would then be unable to charge your battery. That would put a charging source on the output side of the Victron. It is possible if you are designed with a combination inverter/charger/transfer switch like the Xantrex Freedom XC direct to the battery with a “one-way” dedicated DC conductor from the battery to the 12V distribution board (abandoned WFCO converter/charger) but you would also need to ensure your DC-DC converter from tow vehicle is hooked up direct to the battery. This way it is not opposing this DC-DC converter on the main line. I hope this makes sense. I recommend drawing out a schematic and posting for input from the members with electrical experience before committing to any major redesign. That’s what I did and went through several iterations before getting it right.

I installed a Victron lynx distributor bus bar. It connects the inverter charger mppt and Orion dc to dc to a common bus then connected to the battery bank. One fused bus on the lynx feeds the 12 volt loads with a shutoff to dis connect the 12 volt systems. Every thing is fused and a master battery disconnect between the lynx and the battery bank shuts off all the loads and charging source.

It’s an elegant solution.

[Escape_19]

Man oh man...

We bought an Escape travel trailer to go traveling and seeing the country.

Kind of nice and leisurely, now it looks like I need to become a certified electrician

[lostskier]

Originally Posted by rubicon327

Threads like this may inform your decision
https://www.escapeforum.org/forums/f...tml#post439125

I have a 2019 E19 that came with the two 6volts. Had same issues as not enough battery to run the furnace. Yes...I answered your other post. Only upgrade I had to make to existing components was board in the WFPO. GoPower charges just fine in full sun in the SW. Just change to gel battery position. GoPower will tell you that it won't charge to 100%, but that's not really true. If your not able to charge up with solar, just plug it in once in a while and it will get it up to 100%. If you have a plug in for additional solar, you can add to that. I have a 100 that I also plug in. Today, in Big Bend NP, I'm at 100% charged on my 270ah Battleborne. Yes, 270ah...I wanted lots of reserve power. I'm running an Engel freezer and currently working on Starlink. Has enough to last 2-3 days before recharging running both of these. I did add a Victron shunt to monitor the discharge. Oh...the 270ah just fits in the bench seat too. Good luck.