Deep Cycle battery help

Hi,



I have a dometic CFX3 55IM, from tests I've seen it ran for 47 hours at 90F inside car on 40 ah battery (plb40 dometic) and battery was at 0%. I have LED lights around truck also.

I need to run fridge for 3 days straight + led lights for a few hours at night.

If I get X2 Power 27F battery as my starter battery that is around 92Ah. Considering my tacoma will only be able to keep it charged to 80% roughly ~70Ah, will it be able to power cfx3 55 for 3 days?

Or am I better off getting portable 70Ah power-bank + solar panel?

As side note if I get 27F tacoma tray, is that all I need?
Will stock tie down work on x2power 27F?

 

I’d go with the separate power bank.
Maybe one that has the ability to also be charged via a 12v DC supplied by your truck - If needed.

I’m not big on using my main truck battery as a power bank.
Unless you want to carry around a jumper box too.
Then remember to keep it charged as well.

 

Yeah i'm leaning to get deep-cycle battery anyway just to have a backup source and run led lights. But yeah seems like external power-bank makes more sense and more portable.

https://ecoflow.com/collections/river-bundle/products/ecoflow-river-pro-1x-160w-solar-panel

 

Why not just get a solar panel for the plb40?

 

I asked the same type of question and I received a very detailed answer by one of the members. Here is the thread below.

https://www.tacomaworld.com/threads...ation-for-my-new-fridge.710640/#post-25266611

 

I don’t have plb40. I would think ecoflow river + solar is a better option.

 

I have the same battery and can get by 3 days with very minimal driving. Two things to add:
1. You can probably find a local tuner that can do a OVTune type to up your battery charge voltage. Thats what I did. @TWTaco upped my voltage and also added a great tune. Battery now charges at 14.5V
https://www.tacomaworld.com/threads...rea-k-d-tuning-service-paparee-twtaco.707096/
2. Before doing option 1, I would simply charge my battery fully before heading out to a trip. I used a Noco battery charger.

I was between buying an external battery bank or upgrading to AGM. My stock battery started acting up so that pushed me towards the AGM. Now I'm glad I dont have to lug around another battery.

 

Ah interesting so 70ah would roughly equal to 3 days with dometic.

 

I think I might buy both now lol, but yeah topping up with Noco good option.

I have 2.7L, no ovtune for 4 cylinderers yet.

 

The CFX3 55IM is rated at approximately 9 Amps when operated at 12 volts DC. That's about 108 watts

For a 70ah battery, the following calculations should apply.

70ah battery = 840 watt/hours
840 watt/hours divided 108 watts = 7.7 hours

Thats just what the calculations say. Actual usage may be a little different. But it's a long way from being 3 days?

Also, you should never run your battery down to "0". As a rule-of-thumb, you should only use 80% of the full capacity of the battery. Charging to fast (or hot) and running a battery down to LVC (Low Voltage Cut-off) will reduce the life span of your batteries. Batteries are to expensive to abuse.

Just my $0.02

 

Yeah no I would never run battery into 0.

From dometic website:

" Energy Consumption 12 V DC (Internal @ 4 C, Ambient @ 32 C) 1.10 Ah/h "

I think 9 amps is in freezer mode, no? ~ 8 hours ?

So i'm looking at following numbers -20% for real life use without top in up with solar panel:
In cooler mode at 37F from what I understand it is 0.8-1.2 Ah ~ 60 hours?
In cooler mode plus Ice-maker it is 3-5 Ah ~ 14 hours ?

 

Why only 80%? I know you dont want to get it down past 50% otherwise you risk damaging the battery.

 

I believe 50% rule is for standard car batteries not deep cycle ones.

 

?

 

I think I'm going to go with a budget route and run with either a Newport Vessel battery box or a Cutting Edge Portable Solar battery box with 100ah 12V deep cycle battery.

$70 Newport Trolling Motor Smart Battery Box Power Center with USB and DC Ports, Medium

https://www.amazon.com/Newport-Vess...words=battery+box&qid=1617235285&sr=8-1-spons

https://cuttingedgepower.com/produc...81z-OxdOE9B5lbIvGCksHdzb0_pFx7PBoCYIMQAvD_BwE

$180 Weize Deep Cycle AGM 12 Volt 100Ah Battery, Maintenance-Free, 3% Self-Discharge Rate, 1150A Max Discharge Current, Perfect for RV, Solar, Trolling Motor, Wind, Marine, Camping and Off-Grid System

https://www.amazon.com/Weize-Batter...00ah+deep+cycle+battery&qid=1617235327&sr=8-5

 

80% rule is for the newer technology batteries. Lithium? May not apply to Lead / Acid?

I don't claim to be an expert. I learned these formulas and rules from the RC Hobby.

Also - Not sure of the fridge has a cycle time ON - OFF like a household fridge? That would extend the battery time.

 

This is sweet, how do you charge battery inside of it ?

 

You will just have to open up the first one and connect the battery to a charger. The second box can be connected to a solar panel. I'm trying to decide with box to get.

 

What I'm about to say is rooted in 0 Electrical Engineering and 0 knowledge whatsoever lol.

To me 100% charge in battery bank like plb40 or AGM battery is the batteries range of state of charge from 100% to 50%, meaning it's all about Ah at 12v, how long can battery provide current of 12v, because appliance needs 12v.

I'm assuming AGM battery that rated at 70Ah meaning 70ah at 12v is batteries 100% - 50% state of charge range.


Now If I was designing a battery charge display that shows 100% to 0% range of charge, I would not display battery State of Charge, because end user doesn't need to know how much battery holding charge in terms of physics. Customer cares about how much battery has "Charge" left to provide 12v current. So incase of plb40 or goal zero, etc, if display shows 0% charge left battery pack itself is at ~55% State of Charge and internals shutting of current to prevent killing battery by draining it past dangerous state of charge.

So i'm assuming some people over time took it a bit further and probably prefer to discharge AGM only till 60% state of charge which would equal roughly to 20% Ah left for battery to provide you current of 12v.

I'm probably so wrong lmao.