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Nightjar. I have 2 of these in my shed, but use the BMPRO as a monitor on both van and car. Also doesn't stop under voltage unless you look at it.

https://teambmpro.com/products/bluetooth-battery-monitor-batterycheck100/

I liked these as no holes to drill, no extra wiring, just bolt on.

CTXKID - I'll certainly look at one of these as not only is there no under voltage protection on the Travel Buddy, my Engel is 26 years old and although it might have some under voltage cut out, it's lower than what I want to go to.

A 12V AGM @ 12.0 V, at rest is 50% discharged, that's as low as I want to go and what I would set the cut off to. However under load the voltage will be lower. The way I would check that is;

My Travel buddy draws 6A and is usually on for an hour at a time to heat what I cook. The Engel draws 3A, so when both are on the total current is 9A. If I set the oven for one hour and Engel on I'd have the battery at 60% so it is near 50% after an hour and then check the load voltage. Then set the device to just under that. The battery would then recover some voltage when the oven is off. That would be my worst case scenario.

What is the wiring of these things, there's little info on Ebay? i.e. what terminals are there?
 
Condor, Bicter, CTX or any other who can help?
Have often thought about it but hesitated, would using a bread maker be out of the question while free camping, considering the bake time is around an hour?
Have a large inverter hard wired in caravan.
 
Nightjar, an article in the Caravaners Forum related to your query, although it probably doesn't fully answer your question
https://www.caravanersforum.com/viewtopic.php?t=39322
It would be a good idea to do a trial run at home.
Check the power that it draws, & remember the inverter isnt 100% efficient, so total power drawn by the inverter will be slightly higher than that stated on the bread maker. Handy if you have an in-line power meter to give you a full idea of AmpHr or WattHours used.
 
Nightjar said:
Condor, Bicter, CTX or any other who can help?
Have often thought about it but hesitated, would using a bread maker be out of the question while free camping, considering the bake time is around an hour?
Have a large inverter hard wired in caravan.

Nightjar,

What Ded driver said :)

The below is based on a guess of 2000W power rating, if it is a lot less the answer will be different.

There is an interesting thread here https://www.exploroz.com/forum/103482/how-much-power-does-a-breadmaker-use discussing the use of one on 12v

Unfortunately, if the bread maker is rated around 2000W, it will try to draw more than 170Amps (accounting for inverter efficiency) for some periods of the heating cycle. Your batteries may be able to provide this current for a short period but I would imagine you would kill them very quickly if the heating cycle occurred for long or multiple periods.

As a thumbnail calculation, if the breadmaker ran at 2000Watts for fifteen mins twice during the cooking period, the draw from the battery would be 170 Amps for 30 Mins. This works out to be 85 AH drained from your battery bank without considering any other current draw by fans or motors during the total cycle.

You could experiment by using the Wattmeter you've just ordered from ebay to measure the 12v power used to run a complete cycle of breadmaking (provided you have an inverter large enough and a deep cycle battery of 100AH or so before you begin. Just make sure the battery is fully charged and monitor the battery condition as you go.

Having said all that the simple solution, if fuel supply isn't a problem, would be to run the genny for the duration of cooking or crank up the camp oven :)
 
Nightjar,
Further reading on the thread I linked previously provided the following:

"These are measured currents (at 240V) of a Panasonic 550 watt bread maker.
25 minutes at .25 amp
53 minutes at 0 amp
9 minutes at 2.3 amp
45 minutes at 2.3 amps which cycles at about 50%
Allowing for 85% efficient inverter the max amps at 12 volt is about 55 amps.
Total A/h between 25 to 30A/h depends on whether you want a light or dark crust."

It really shows the importance of getting a low wattage breadmaker. Maybe they are all the same wattage and my original guess at wattage was way off.

The numbers do look pretty good for you if you can get a breadmaker with similar specs.

Your next concern is your ability to replace the power used in a timely manner while on solar.
 
bicter said:
Having said all that the simple solution, if fuel supply isn't a problem, would be to run the genny for the duration of cooking or crank up the camp oven :)

Me thinks you have nailed the the simple bread making.
Me cutting a mates loaf he baked using genny. (Jon is a wag who donated these Jimmy hats)

1572567229_33.peter_cutting_a_slice_of_jon_s_bread-mt.celia.jpg
 
There's one thing that has not been discussed (to my knowledge) and that is battery discharge rate, or, C rating, or as described in Peukert's law. So here is some data taken from the "Home of 12V" Adelaide for a 100AH Thumper Extreme AGM.

Maximum discharge current 1100 Amp 5 seconds
Maximum charging current 30 Amps

Discharge Rate Ah Capacity

20 Hour Rate 105 Ah
10 Hour Rate 100 Ah
5 Hour Rate 94 Ah
1 Hour Rate 73 Ah

So as you can see the more you draw at one time, the less there is to draw. So what does it mean? At the 20 yr rate you divide AH by hours i.e. 100/20 = 5amps. So if you draw 5 amps constantly you will have 5 amps left. The above discharge rates mean you can draw the following amps for that time;

20 hr rate = 5 amps
10 Hour Rate = 10 amps
5 Hour Rate = 19 amps (a bit less)
1 Hour Rate = 73 amps

This will flatten the battery, but the obvious here is that if you draw a heavy current, (the 1 hr rate) you get < 75% of capacity. I'll give another example next post.
 
Say you have a microwave you want to run off an inverter from a battery. I'll use my van M/W as an example.

M/W = Daewoo 20lt. Power is rated at 700W however, it needs 1100W as the power input. (About as small a microwave as you can get)

1100W @ 240VAC = 4.6 amp load.

4.6A @ 240VAC inverted = 91.7A. Then you need to add the inefficiency factor of an inverter, so I'll use 10%. This adds an extra 9.2 amps = in round figures 101 amps draw.

So I'm hovering on the 1 hour rate. To Nuke a frozen dinner might take 6 minutes (some take 7). This equates to 1/10th of the AH used = 10 amps = 10% of capacity. This means you think you have 90AH left in your battery.

However, given that it is in the 1 hour C rating the simple math is to look at 10AH as a % of 73 amps (the 1 hour C rating) = 13.7% So in actual fact you don't have 90 AH left you only have a bit over 86 AH.

In other words, the higher the amp load, the less capacity you have.

Conclusion - To maximise battery life try to keep within the 20 to 10 hour C rating. For 100AH that is between 5 and 10 amps. If you need twice that in amps, then you need twice than in battery capacity.
 
BTW I looked up a Breville bread maker rated at 800W.

It would use about 83AH for an hours use.

My suggestions as an alternative.

Buy a camp oven if you haven't already.

Go to Woolies, Coles, Aldi etc and buy a loaf.

or

run it off the genny :) :)
 
You can't always get bread in the local towns and when you can it's usually frozen, crap and over priced.
Plus getting into town to begin with can be a hassle if you're out in the sticks and might only happen once a month or fortnightly.

Camp ovens are good but the old bread maker is brilliant. Same loaf every time. Just run it off the genny.
 
More on my stuffed battery.

So, yesterday I went into town did some shopping, used the Engel and while driving the Redarc kept the battery up. I emptied the fridge, turned it off and then turned the engine off.

Lunchtime today the battery showed 12.6 V, this indicates about 86% capacity. I used the Travel Buddy for 1 hour to cook lunch.

As soon as I turned the oven on the voltage dropped to 12.2 V and an hour later was 12.0 V. When the oven turned off the voltage came back up to 12.4 V.

Two things to note;

1. When there was a 6 amp load from the oven, the voltage dropped 0.4 V
2. As the battery had no load overnight, it should show nearer 12.9 V as it was full. This indicates the battery is definitely not holding charge after I flattened it a week ago.

I'll try to resurrect it, but don't hold much hope :)

Just imagine where the voltage would go under an inverter load of 75 amps........
 
Damn, that piccy of the breads got me salivating :)

Unless you have a huge battery capacity, solar recharge capability and if fuel is readily available to run the genny, I think that the genny is the best way.
This leaves your battery system unmolested by large current draws.

Top Hat BTW
 
condor22 said:
Nightjar. I have 2 of these in my shed, but use the BMPRO as a monitor on both van and car. Also doesn't stop under voltage unless you look at it.

https://teambmpro.com/products/bluetooth-battery-monitor-batterycheck100/

I liked these as no holes to drill, no extra wiring, just bolt on.

CTXKID - I'll certainly look at one of these as not only is there no under voltage protection on the Travel Buddy, my Engel is 26 years old and although it might have some under voltage cut out, it's lower than what I want to go to.

A 12V AGM @ 12.0 V, at rest is 50% discharged, that's as low as I want to go and what I would set the cut off to. However under load the voltage will be lower. The way I would check that is;

My Travel buddy draws 6A and is usually on for an hour at a time to heat what I cook. The Engel draws 3A, so when both are on the total current is 9A. If I set the oven for one hour and Engel on I'd have the battery at 60% so it is near 50% after an hour and then check the load voltage. Then set the device to just under that. The battery would then recover some voltage when the oven is off. That would be my worst case scenario.

What is the wiring of these things, there's little info on Ebay? i.e. what terminals are there?

The link is for the latest BMPro. Do you have it, or an earlier version, as the latest has a better capacity for high current drains.

Rob P.
 
Pablo, I have the earlier version, but even so the shunt in it will handle 100 A far more than I ever use.

As I mentioned before, there are only 2 devices I need in my van that are 240 VAC only - The ultrasonic cleaner and the toothbrush charger. They both work off a 150 W Projecta Inverter. So 15A + 10% = a max of 17A. If I used normal items the max total would be 25 A at any one time or 35 A with the heater glow pin for a minuter or so.

The other 2 are the microwave and aircon and I use the genny for them.
 
condor22 said:
Pablo, I have the earlier version, but even so the shunt in it will handle 100 A far more than I ever use.

As I mentioned before, there are only 2 devices I need in my van that are 240 VAC only - The ultrasonic cleaner and the toothbrush charger. They both work off a 150 W Projecta Inverter. So 15A + 10% = a max of 17A. If I used normal items the max total would be 25 A at any one time or 35 A with the heater glow pin for a minuter or so.

The other 2 are the microwave and aircon and I use the genny for them.

I have used several of the earlier versions, but the new "van" I acquired came with a 2000W inverter. Not that I have used it, but it meant that I couldn't run the full potential battery load through the BMPro, and meant that I had to split inverter load to bypass the earlier BMPro. Fortunately I have been involved in an early beta tester/adopter program with them, which has saved cost. The latest version is also suitable for the Lithium battery range that they have been promoting. I have also found the latest version super easy to use, and the Bluetooth more reliable, than some earlier versions.

Rob P.
 
Thanks for the info Rob, but I already spent the money and am loath to spend more.

The only issue I've had is the Bluetooth occasionally freezes. The only fix is to undo the + term on the battery, disconnect the BM lead momentarily from the battery and refix. The issue doubles to an extent as I have 2 of the bloody things and have to disconnect from one battery, then connect to the other and vice verca re bluetooth to monitor both..

This also resets the capacity reading to 50% until the battery has had an amount of charge. When this happens I have a fair idea what capacity I have left. Others with less technical knowledge may well be frustrated with this problem.

I did contact the manufacturer re this and hoped they could rejig the app to do this, their reply was that they were looking to fix this, that was 3 years ago and haven't heard anything since. I can only hope the later version has fixed it. Can't say much about their followup customer support and am disappointed.

The concept is great, but hey they have my money and don't seem interested now they have.
 

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