6 Volt VS 12 Volt

[MarcW-THOR]

Our son in law installed a lithium in their motorhome this year and worked great until he was driving through Las Vegas this summer. The heat killed it at 110. He had to wait for the temperatures to drop before they worked again. Not sure if this is normal with lithium.

 

[Beau388]

Our son in law installed a lithium in their motorhome this year and worked great until he was driving through Las Vegas this summer. The heat killed it at 110. He had to wait for the temperatures to drop before they worked again. Not sure if this is normal with lithium.

Yes that is typical of the battery's management system. Typical temperature restrictions are 32 F degrees to 120 F for charging and 4 F to 140 F for discharging. Sun shining on the house battery compartment when parked at 100+ F ambient will often shut down the batteries. The batteries generate considerable heat when being charged or discharged. Living in south Texas I installed as small temperature controlled 12 volt fan in the house battery compartment and put a 120 volt heat mat under the batteries.

 

[ducksface]

Heat mat
And
Thermostatically controlled giant 12v computer fan for me. It airs the entire bin and dc to dc

But I don't think I could beat the ambient in Vegas or Havasu.
My next mod will be for the lithiums to be moved inside to under the passenger seat.
An easy move from the passenger bin they sit in now.

 

[Bob Nodine]

Thanks for all the information it's very much appreciated.

When I purchased the motorhome it came with 2 group 27 batteries. They did not last long at all. I made provisions for 3 group 31 batteries and that has worked well but are bad now and in need of 3 more.

One of my issues I seem to have is not being able to manage the depth of a charge. Meaning....the touch panel indicates the batteries are charged 13.5 volts also with a volt meter measuring off the batteries.

How can you visually see how charged the batteries are (full capacity) . I understand a fully charged battery is 12.65 volts but how can you determine it is at full capacity. I hope I am making sense to someone?

Also a battery should not be discharged below 50% of capacity. If 12 65 volts is fully charged how many volts would be at 50%?

I was always instructed to never run a battery lower than 11 volts. How do you measure the 50% left in a battery.

Most of that goes out the window with Lithium Iron Phosphate batteries. You can discharge them to near zero and while you are doing this the output voltage stays flat. That means your inverter will also work until the battery is almost completely discharged.

As to knowing how much charge is left in your batteries that term is known as the State of Charge (SOC) and is monitored by a shunt that tracks the amp hours in and out of the battery (batteries). When the battery bank is fully charged the SOC is set to 100%. As you use energy from the battery bank the SOC is decreased. When the batteries are charged the SOC is increased. These two functions compliment each other so if your solar panels are putting energy in while you are taking energy out the resulting SOC will reflect the plus/minus result.

Here is a decent shunt that you can monitor with the Bluetooth on your cellphone:
https://tinyurl.com/2ylgzyro

 

[Machinetools1]

Fantastic and thanks for the input. I did a search on the best shunt and believe it or not this one had come up as the best.

I am very intrigued with the Lithium batteries. My concern is the hot weather.

We live in an arid area and the Temps reach 117 in the summer time and it gets 14 degrees in the winter.

We got stuck in the big freeze in Texas a few years back and we were definitely not prepared.

Is there a way to keep the temperature consistent in the standard battery compartment without relocating the batteries?

 

[PS89]

We live in an arid area and the Temps reach 117 in the summer time and it gets 14 degrees in the winter.

Note that Beau388 already gave you general information regarding this.


You'll have to check the specifications for whatever battery you select in order to make the final decision. Once you have firm numbers in hand, you can also make decisions as how to manage the system.

 

[ducksface]

Cut a three inch hole from your interior living space to the battery compartment and install a computer fan.
It will help considerably.

 

[16ACE27]

Cut a three inch hole from your interior living space to the battery compartment and install a computer fan.
It will help considerably.

if the 29M is like our ACE it will do nothing as the house battery compartment is a multi-sided metal tray with many openings to the ambient environment. relocating the batteries or closing in the compartment would be the only options.

 

[dkoldman]

Fantastic and thanks for the input. I did a search on the best shunt and believe it or not this one had come up as the best.

I am very intrigued with the Lithium batteries. My concern is the hot weather.

We live in an arid area and the Temps reach 117 in the summer time and it gets 14 degrees in the winter.

We got stuck in the big freeze in Texas a few years back and we were definitely not prepared.

Is there a way to keep the temperature consistent in the standard battery compartment without relocating the batteries?

Not sure of brand and age of your Lithium battery, but given heat temperatures is a thing for you, check the specifications of the next Lithium battery you buy.

Mine is 4 - 5 months old and it will not caught off unless it is 194 F

BMS High Temp Protection Cutoff:194°F
BMS High Temp Protection Restart:149°F

My batteries are outside under steps, so it additionally gets heat from the engine. No issues thus far and I have used in Summer heat if Texas. Maybe not as bad as Vegas?

 

[Beau388]

Not sure of brand and age of your Lithium battery, but given heat temperatures is a thing for you, check the specifications of the next Lithium battery you buy.

Mine is 4 - 5 months old and it will not caught off unless it is 194 F

BMS High Temp Protection Cutoff:194°F
BMS High Temp Protection Restart:149°F

My batteries are outside under steps, so it additionally gets heat from the engine. No issues thus far and I have used in Summer heat if Texas. Maybe not as bad as Vegas?

【Intelligent Charging Protection】NewtiPower LiFePO4 battery has built-in 150A BMS (battery management system) to protect the battery from overcharge, overdischarge, overcurrent and short circuit with excellent self discharge rate. Built in temperature protection function, BMS cuts off charging 32℉ (0℃). High temperature cut-off can prevent charging from exceeding 158 ℉ (70 ℃)

From LiTime - Charge Temperature 32℉ ~ 131℉ (0℃ ~ 55℃)

My battery compartment is a the same as a Thor MC 29M. Steel with many holes. In fact the entire top half of the rear facing the drive shaft is open (11" x10") and partially filled with cable and pipe runs for the kitchen.

 

[16ACE27]

My battery compartment is a the same as a Thor MC 29M. Steel with many holes. In fact the entire top half of the rear facing the drive shaft is open (11" x10") and partially filled with cable and pipe runs for the kitchen.

Sounds like my ACE battery compartment.

 

[Beau388]

Sounds like my ACE battery compartment.

Yep all Thor MC plant 750 products.

 

[dkoldman]

【Intelligent Charging Protection】NewtiPower LiFePO4 battery has built-in 150A BMS (battery management system) to protect the battery from overcharge, overdischarge, overcurrent and short circuit with excellent self discharge rate. Built in temperature protection function, BMS cuts off charging 32℉ (0℃). High temperature cut-off can prevent charging from exceeding 158 ℉ (70 ℃)

From LiTime - Charge Temperature 32℉ ~ 131℉ (0℃ ~ 55℃)

My battery compartment is a the same as a Thor MC 29M. Steel with many holes. In fact the entire top half of the rear facing the drive shaft is open (11" x10") and partially filled with cable and pipe runs for the kitchen.

Looks like NewtiPower has better high temp rating

FWIW, I have 300ah and their website shows 250Amps BMS

Intelligent Charging Protection】NewtiPower LiFePO4 battery has built-in 250A BMS (battery management system) to protect the battery from overcharge, overdischarge, overcurrent and short circuit with excellent self discharge rate. Built in temperature protection function, BMS cuts off charging 32℉ (0℃). High temperature cut-off can prevent charging from exceeding 158 ℉ (70 ℃).Our BMS supports both series and parallel connections, but we recommend not exceeding 6 batteries.​

Also for what it is worth, I got the below specifications from Newtipower's Support about 4 - 5 months ago. It was not available on a website at the time and they may have made some adjustments as they grow?

High Volt Disconnect: 14.8V
Charge Voltage: 14.6V
Equalize Charge Volt: 14V
Boost Charge Volt: 14.4V
Float Charge Volt: 13.8V
Boost Char Return Volt: 13.2V
Over Disc Return Volt: 14.2V
Low Voltage Alarm: 12V
Over Discharge Volt: 10V
Discharge Limit Volt: 10V
BMS SOC Cutoff:0%
BMS Low Voltage Cutoff: 11.6V
BMS Low Temp Charging Cutoff: 32.0°F
BMS Low Temp Charging Restart: 37.4°F- 41°F
BMS High Temp Protection Cutoff:194°F
BMS High Temp Protection Restart:149°F


I may have to ask them if the 194F High Temp cutoff should be changed to 158F. I chose to ignore the battery temp sensor setup on my Victron in favor of showing input voltage of Starter battery. Unless those batteries get really really hot when charging, I doubt I would ever see 158F plus

 

[Beau388]

I may have to ask them if the 194F High Temp cutoff should be changed to 158F. I chose to ignore the battery temp sensor setup on my Victron in favor of showing input voltage of Starter battery. Unless those batteries get really really hot when charging, I doubt I would ever see 158F plus

I have 4, 120 A-H, 12 volt Newitpower LFP batteries in my golf cart. We have only had two mornings in 2023/4 where the temperatures were below 0 C (32 F). The golf cart ran fine and I did not notice any excessive amperage draw. On the high side we have had about 45 days where the day time temperature was 100 F or above. Again, absolutely no problems of any kind. I don't need to charge the cart but about every 30 days (about 35 miles around the Village or out to the QT gas center and the most of the county roads around here are not suitable for LSV and golf carts).

I have an automatic charger, so I plug the cart in at about 7 pm after the supper trip. The charger shows charging voltage, amperage, accumulated amp-hours and charger temperature. When the first battery's BMS shuts off charging, the charger shuts down. When I getup the next morning the golf cart is ready for another 30 days travel.

I tried to wire and equip my Hurricane to work the same way, all automatic.

 

[dkoldman]

I have 4, 120 A-H, 12 volt Newitpower LFP batteries in my golf cart. We have only had two mornings in 2023/4 where the temperatures were below 0 C (32 F). The golf cart ran fine and I did not notice any excessive amperage draw. On the high side we have had about 45 days where the day time temperature was 100 F or above. Again, absolutely no problems of any kind. I don't need to charge the cart but about every 30 days (about 35 miles around the Village or out to the QT gas center and the most of the county roads around here are not suitable for LSV and golf carts).

I have an automatic charger, so I plug the cart in at about 7 pm after the supper trip. The charger shows charging voltage, amperage, accumulated amp-hours and charger temperature. When the first battery's BMS shuts off charging, the charger shuts down. When I getup the next morning the golf cart is ready for another 30 days travel.

I tried to wire and equip my Hurricane to work the same way, all automatic.

I have been impressed with NewtiPower. I didn't need to see it cut open to see they had checked all of the boxes. If there were any doubts that is what warranty, Amazon customer service and my Credit Card is for

At any rate I did check with NewtiPower support to get the latest on my 300ah high temperature specifications.

Dear Coleman,

Sorry for keep you waiting.

Our 12V 300Ah battery protection plate has a high temperature protection of 85°C (185°F) and a temperature protection release value of 50°C (122°F).

Please do not hesitate to contact us if you have other concerns.
Have a great day!

Senior Customer Service Specialist
___________________________________________________________________
NewtiPower-Lithium Battery Manufacturer​

So for OP, it may be worth noting age and brand of existing Lithium battery and/or actual peak temperature in compartment closure.

In the meantime, I have updated my notes on 300ah Newtipower for future.

High Volt Disconnect: 14.8V
Charge Voltage: 14.6V
Equalize Charge Volt: 14V
Boost Charge Volt: 14.4V
Float Charge Volt: 13.8V
Boost Char Return Volt: 13.2V
Over Disc Return Volt: 14.2V
Low Voltage Alarm: 12V
Over Discharge Volt: 10V
Discharge Limit Volt: 10V
BMS SOC Cutoff:0%
BMS Low Voltage Cutoff: 11.6V
BMS Low Temp Charging Cutoff: 32.0°F
BMS Low Temp Charging Restart: 37.4°F- 41°F
BMS High temperature protection of 85°C (185°F)
BMS High temperature protection release value of 50°C (122°F)

 

[GI_Tom]

To all the contributors here, a big hearty thank you. I had to swap out batteries this weekend, both chassis and house. My first run ins with 6v batteries (4 of them wired in series). All of the content here (and some other posts) helped me a lot in getting that done. Ultimately, hope to change out to 2 12's next time so long as I'm confident I won't fry myself or the RV. Happy New Year to all.

 

[16ACE27]

To all the contributors here, a big hearty thank you. I had to swap out batteries this weekend, both chassis and house. My first run ins with 6v batteries (4 of them wired in series). All of the content here (and some other posts) helped me a lot in getting that done. Ultimately, hope to change out to 2 12's next time so long as I'm confident I won't fry myself or the RV. Happy New Year to all.

I don't think so: That would give you 24 volts. I hope you didn't wire the new batteries that way.

In reality your four 6 volt batteries were wired in a series/parallel configuration:
Two sets of two batteries in series giving you 12 VDC, and those two sets being wired in parallel to increase storage capacity.

 

[ducksface]

if the 29M is like our ACE it will do nothing as the house battery compartment is a multi-sided metal tray with many openings to the ambient environment. relocating the batteries or closing in the compartment would be the only options.

I enclosed mine eliminating all leaks and insulating with foam sheet and kilmat.
It was one of the more hateful jobs I've done on the rv.

Ssssoooo many gaps and stupid angles.

If I were to do it again I'd cut five gallon pickle buckets Into slabs and squares and heat mold them to fit with an hf heat gun.
Screw one side somewhere flat(ish) and heat bend the plastic around the stupid edges and angles.

 

[Bob Nodine]

I have been impressed with NewtiPower. I didn't need to see it cut open to see they had checked all of the boxes. If there were any doubts that is what warranty, Amazon customer service and my Credit Card is for

At any rate I did check with NewtiPower support to get the latest on my 300ah high temperature specifications.

Dear Coleman,

Sorry for keep you waiting.

Our 12V 300Ah battery protection plate has a high temperature protection of 85°C (185°F) and a temperature protection release value of 50°C (122°F).

Please do not hesitate to contact us if you have other concerns.
Have a great day!

Senior Customer Service Specialist
___________________________________________________________________
NewtiPower-Lithium Battery Manufacturer​

So for OP, it may be worth noting age and brand of existing Lithium battery and/or actual peak temperature in compartment closure.

In the meantime, I have updated my notes on 300ah Newtipower for future.

High Volt Disconnect: 14.8V
Charge Voltage: 14.6V
Equalize Charge Volt: 14V
Boost Charge Volt: 14.4V
Float Charge Volt: 13.8V
Boost Char Return Volt: 13.2V
Over Disc Return Volt: 14.2V
Low Voltage Alarm: 12V
Over Discharge Volt: 10V
Discharge Limit Volt: 10V
BMS SOC Cutoff:0%
BMS Low Voltage Cutoff: 11.6V
BMS Low Temp Charging Cutoff: 32.0°F
BMS Low Temp Charging Restart: 37.4°F- 41°F
BMS High temperature protection of 85°C (185°F)
BMS High temperature protection release value of 50°C (122°F)

If the outside temperature is above 122 degrees F you should probably stay home and forget camping.

 

[16ACE27]

I enclosed mine eliminating all leaks and insulating with foam sheet and kilmat.
It was one of the more hateful jobs I've done on the rv.

Ssssoooo many gaps and stupid angles.

If I were to do it again I'd cut five gallon pickle buckets Into slabs and squares and heat mold them to fit with an hf heat gun.
Screw one side somewhere flat(ish) and heat bend the plastic around the stupid edges and angles.

I've considered closing mine in as well: it would take one section of foam on the inside but making openings for the cables and hydraulic hoses (the leveling system is also in that compartment). It just hasn't risen high enough on the "to do" list.