NEST Battery Budget

[BeSerious]

Following up on my amp measurements of the NEST 12v refrigerator, I measured the amp draw of the remaining 12v items. (Please see the attached Table.) In the process, I found some omissions on the 12v fuse label. For example, the label doesn’t show which fuse handles the Water Heater (fuse #3) or the Awning Motor (fuse #5). Note: Where items have variable amp draws e.g. the track lights, the table shows both the minimum (low) and maximum (high) amps.

Heavy Hitters — Not surprisingly, the fridge @ 4a and furnace @ 3.5a are big 12v amp users. But so is the “disco” track light @ 3.2a, when set to high. And the awning motor @ 6a+, which restricts its use while boon-docking.

Boon-docking Scenarios — The table also includes estimates of daily amp hours consumed assuming two boon-docking scenarios -- “normal” and “conservative”. Both scenarios assume mild weather with limited use of the lights, hot water, etc.. The amp hours of some items are easy to estimate, because they are controlled directly e.g. lights, water pump, water heater etc.. But the duty cycle of the two biggest 12v users (the fridge and furnace) depend on the weather, temperature settings and usage (e.g. how many times the fridge is opened, etc.). The “normal” scenario requires roughly 35 Ah/day. While the “conservative” scenario requires roughly 27 Ah/day.

Parasitic Loads — Almost all of the fuses have some constant (parasitic) amp draw (italics in the table). While each one is pretty small (.01 - .17amps), together they consume 12.5 Amp Hours (Ah) per day. This means that in the “conservative” scenario, the parasitic loads are nearly half of the total Ah/day usage

Boon-docking Battery Budget — A fully charged pair of stock 12v group 24 Interstate batteries can deliver roughly 84Ah with a 50% draw down. So the 84 Ah battery budget will only last a little over 2 days in the “normal” scenario and 3 days in the “conservative” one.

[mtbmitch]

I have seen 100 amp lithium rv batteries in the 550$ range on ebay. 2 of these would double your boon docking capability as well as loosing some weight.

[Prettygood]

This is where a single 100ah Battle Born lithium makes so much sense. You could get 3 days of use without restoring a single amp to the battery. A small 150w solar setup makes it almost unlimited.

[TheHoff]

Originally Posted by BeSerious

Following up on my amp measurements of the NEST 12v refrigerator, I measured the amp draw of the remaining 12v items. (Please see the attached Table.) In the process, I found some omissions on the 12v fuse label. For example, the label doesn’t show which fuse handles the Water Heater (fuse #3) or the Awning Motor (fuse #5). Note: Where items have variable amp draws e.g. the track lights, the table shows both the minimum (low) and maximum (high) amps.

Heavy Hitters — Not surprisingly, the fridge @ 4a and furnace @ 3.5a are big 12v amp users. But so is the “disco” track light @ 3.2a, when set to high. And the awning motor @ 6a+, which restricts its use while boon-docking.

Boon-docking Scenarios — The table also includes estimates of daily amp hours consumed assuming two boon-docking scenarios -- “normal” and “conservative”. Both scenarios assume mild weather with limited use of the lights, hot water, etc.. The amp hours of some items are easy to estimate, because they are controlled directly e.g. lights, water pump, water heater etc.. But the duty cycle of the two biggest 12v users (the fridge and furnace) depend on the weather, temperature settings and usage (e.g. how many times the fridge is opened, etc.). The “normal” scenario requires roughly 35 Ah/day. While the “conservative” scenario requires roughly 27 Ah/day.

Parasitic Loads — Almost all of the fuses have some constant (parasitic) amp draw (italics in the table). While each one is pretty small (.01 - .17amps), together they consume 12.5 Amp Hours (Ah) per day. This means that in the “conservative” scenario, the parasitic loads are nearly half of the total Ah/day usage

Boon-docking Battery Budget — A fully charged pair of stock 12v group 24 Interstate batteries can deliver roughly 84Ah with a 50% draw down. So the 84 Ah battery budget will only last a little over 2 days in the “normal” scenario and 3 days in the “conservative” one.

Thanks for doing this. Very important info. Interesting that your calculation of 3 days of boondocking exactly mirrored our real-time experience. We got just about 3 days before the refrigerator quit.

[Tamarack]

I'm considering locating the batteries under the seat in the storage compartment. Looks like there's plenty of room and they'd be much more secure inside the trailer. Have any of you considered this option?
Thanks

[TheHoff]

If I had lithium batteries, I might consider the same.

[Inspired_MJ]

Originally Posted by Tamarack

I'm considering locating the batteries under the seat in the storage compartment. Looks like there's plenty of room and they'd be much more secure inside the trailer. Have any of you considered this option?
Thanks

I put 400ah of lithium and a 2k converter/inverter under the bench seats. Took out the battery compartment all together and dropped the nose cargo area 2 inches and add optional 2x25 or 2x30 propane tanks. Still have room.

[Bugbee]

Originally Posted by Inspired_MJ

I put 400ah of lithium and a 2k converter/inverter under the bench seats. Took out the battery compartment all together and dropped the nose cargo area 2 inches and add optional 2x25 or 2x30 propane tanks. Still have room.

Was this on a Nest?

[Inspired_MJ]

Originally Posted by Bugbee

Was this on a Nest?

Yes I have a 2019.

[Tamarack]

Originally Posted by Inspired_MJ

I put 400ah of lithium and a 2k converter/inverter under the bench seats. Took out the battery compartment all together and dropped the nose cargo area 2 inches and add optional 2x25 or 2x30 propane tanks. Still have room.

Thanks for the information. I was also considering an extra propane tank.
Your 400ah make my two little 120's look pitiful

[love nest]

Originally Posted by BeSerious

Following up on my amp measurements of the NEST 12v refrigerator, I measured the amp draw of the remaining 12v items. (Please see the attached Table.) In the process, I found some omissions on the 12v fuse label. For example, the label doesn’t show which fuse handles the Water Heater (fuse #3) or the Awning Motor (fuse #5). Note: Where items have variable amp draws e.g. the track lights, the table shows both the minimum (low) and maximum (high) amps.

Heavy Hitters — Not surprisingly, the fridge @ 4a and furnace @ 3.5a are big 12v amp users. But so is the “disco” track light @ 3.2a, when set to high. And the awning motor @ 6a+, which restricts its use while boon-docking.

Boon-docking Scenarios — The table also includes estimates of daily amp hours consumed assuming two boon-docking scenarios -- “normal” and “conservative”. Both scenarios assume mild weather with limited use of the lights, hot water, etc.. The amp hours of some items are easy to estimate, because they are controlled directly e.g. lights, water pump, water heater etc.. But the duty cycle of the two biggest 12v users (the fridge and furnace) depend on the weather, temperature settings and usage (e.g. how many times the fridge is opened, etc.). The “normal” scenario requires roughly 35 Ah/day. While the “conservative” scenario requires roughly 27 Ah/day.

Parasitic Loads — Almost all of the fuses have some constant (parasitic) amp draw (italics in the table). While each one is pretty small (.01 - .17amps), together they consume 12.5 Amp Hours (Ah) per day. This means that in the “conservative” scenario, the parasitic loads are nearly half of the total Ah/day usage

Boon-docking Battery Budget — A fully charged pair of stock 12v group 24 Interstate batteries can deliver roughly 84Ah with a 50% draw down. So the 84 Ah battery budget will only last a little over 2 days in the “normal” scenario and 3 days in the “conservative” one.

Morning
Very good info. Just wonder about the .24a = 12.5a .24x24 = 5.76a let me know where I went wrong.

Thanks

[BeSerious]

Originally Posted by love nest

Morning
Very good info. Just wonder about the .24a = 12.5a .24x24 = 5.76a let me know where I went wrong.

Thanks

Thanks for catching an error in the spreadsheet. The formulas that added up the parasitic loads included the number 7 instead of the cell M7 or R7 So the parasitic load is a lower % of the total in both scenarios.



BeSerious

[Tamarack]

Originally Posted by Inspired_MJ

I put 400ah of lithium and a 2k converter/inverter under the bench seats. Took out the battery compartment all together and dropped the nose cargo area 2 inches and add optional 2x25 or 2x30 propane tanks. Still have room.

If it's not too much trouble, would you mind sharing some photos of your battery installation and the nose cargo area?
Thanks

[Tamarack]

Looks like the middle compartment is the best choice for my two batteries. Now I need to come up a plan for securing them. I think I can use the original battery cables pulled inside, although I hope to make it look a little neater than what came from the factory. Maybe I will go with two propane tanks in the nose cone...?

[love nest]

Originally Posted by Tamarack

Looks like the middle compartment is the best choice for my two batteries. Now I need to come up a plan for securing them. I think I can use the original battery cables pulled inside, although I hope to make it look a little neater than what came from the factory. Maybe I will go with two propane tanks in the nose cone...?

Morning
looks like a nice spot. I was wondering what the recommended charging voltage are for your new batteries. I think they recommend 14V. I see that my converter will not get more then 13.2v on the meter panel and about 13.28 with my VOM at the battery. I think some battery companies recommend a DC-DC converter. Especially if you TV has a smart alternator. FYI

[BeSerious]

When I was mapping out our battery upgrade path I discovered some very good threads discussing the need to upgrade the electronics if you switch to Lithium batteries.

https://www.airforums.com/forums/f449/

And some advice on upgrading the electronics even if you just want to really deep cycle 6V golf cart batteries. Look for posts by AirMiles.

https://www.airforums.com/forums/f44...es-195139.html

BeSerious

[Tamarack]

Originally Posted by BeSerious

When I was mapping out our battery upgrade path I discovered some very good threads discussing the need to upgrade the electronics if you switch to Lithium batteries.

https://www.airforums.com/forums/f449/

And some advice on upgrading the electronics even if you just want to really deep cycle 6V golf cart batteries. Look for posts by AirMiles.

https://www.airforums.com/forums/f44...es-195139.html

BeSerious

Thanks a bunch! I had already purchased an upgraded converter that can handle the 14v+ required, but it looks like the threads you recommended have some excellent/detailed info!

[love nest]

Originally Posted by Tamarack

Looks like the middle compartment is the best choice for my two batteries. Now I need to come up a plan for securing them. I think I can use the original battery cables pulled inside, although I hope to make it look a little neater than what came from the factory. Maybe I will go with two propane tanks in the nose cone...?

Hello
Did not connect you to this thread. I am in the first stages of up grading. noticed your wiring on the breaker buss is the same as mine was(incorrect). I worked with the factory and they sent me the correct breakers to bring it up to spec. check this thread. I have pics

13 Attachment(s) You are subscribed to this thread; No Battery Power When Boondocking

[Tamarack]

Originally Posted by love nest

Hello
Did not connect you to this thread. I am in the first stages of up grading. noticed your wiring on the breaker buss is the same as mine was(incorrect). I worked with the factory and they sent me the correct breakers to bring it up to spec. check this thread. I have pics

13 Attachment(s) You are subscribed to this thread; No Battery Power When Boondocking

Thanks! Checking and correcting the breakers is definitely on my "to do" list

[andee_lane]

I'm in the process of upgrading my Nest batteries to Lithium and have appreciated the information and photos you all have shared. I plan to move the batteries inside to the center front storage area (as Tamarack did), then add another propane tank to the nose cone. Here is my thinking on the bare bones electrical upgrades needed for the trailer. Thoughts and advice?

1. Two 12V Battle Born 100ah Lithium Batteries in parallel (on order)
2. Victron BMV 712 - Current Based Battery Monitor
3. Charger/Converter upgrade to PD 4655L PDA WildKat (as suggested by Randy and ordered from Best Converter)
4. Safety Circuit Breaker upgrades as needed
5. Remove fuse for DC(TV) to DC(TT) - add DC to DC Alternator at later date as needed
6. Zamp exterior portable solar setup at later date as needed
7. Various wire, framing, straps, screws