Forum Discussion
pianotuna
Oct 09, 2014Nomad III
Hi,
Propane generators have some nice attributes--but the easy of refilling is NOT one of them.
Actually AGM lifeline calls equalizing "conditioning". I agree it is not something one would wish to do on a regular basis with agm chemistry--but if there is significant loss of capacity it can (and should) be done.
The idea with battery banks is to use the largest possible cell size that will fit the available space. I'd LOVE to have six two volt cells, however I can't afford the modification nor the actual cells. There is no particular reason to use six volt format with AGM chemistry.
I could run the 400 watt coffee pot and the 800 watt toaster from a 1250 watt inverter--but one would take a peukert "hit", so it is probably better to run them sequentially rather than simultaneously.
Thanks for the information on the NiFe chemistry. I was not aware that they required regular watering. I did know that the electrolyte lasts for up to 30 years and then can be replaced.
How much charging can be done with the engine of your RV?
Hi MTS,
The batteries are not necessarily smaller with 24 volts--but they do work at 50% of the amp-hour draw for the same number of watts. That favors Peukert, of course. And of course as you mentioned 1/2 size cabling.
Hi Davydd,
If you have only 15 amps of shore power and wish to run the fridge, microwave and water heater all at the same time it becomes useful to draw from the battery bank. Particularly when it is -30 and there is no access to the shore power breaker box--which is often the situation I am in. I do use a watt meter and before I had the hybrid inverter I did load balance carefully. Now I don't have to do that any more. It was worth the extra cost to be able to do so.
I disagree totally about solar. For me as a former part time user it was the only way to extend the life of the battery bank. No shore power at any of the storage locations here. I was generator free for five years because I had a solar system.
Once the truly cold weather arrives it is far cheaper to go to a campground and use electric heat as opposed to running the generator and heating with propane. In the worst of the cold last year I was using 5400 watts and my class C was drifted in for four days. If I had been relying on propane I would have had a MAJOR problem refueling the fixed tank. I suppose I could have carried gasoline in a can for the generator. But it is only 2800 watts and while that may have prevented freeze ups it would certainly have been uncomfortable.
Hi Gerry,
I have read the Etrek page before. One of the more surprising things is their choice of a 5k Wagman inverter. Wagman is not very well thought of. Gotta love the 8 AGM batteries. 3500 watts equates to about 270 amps. But that is not a "pure" alternator, rather it is a 120 volt generator.
Propane generators have some nice attributes--but the easy of refilling is NOT one of them.
Actually AGM lifeline calls equalizing "conditioning". I agree it is not something one would wish to do on a regular basis with agm chemistry--but if there is significant loss of capacity it can (and should) be done.
The idea with battery banks is to use the largest possible cell size that will fit the available space. I'd LOVE to have six two volt cells, however I can't afford the modification nor the actual cells. There is no particular reason to use six volt format with AGM chemistry.
I could run the 400 watt coffee pot and the 800 watt toaster from a 1250 watt inverter--but one would take a peukert "hit", so it is probably better to run them sequentially rather than simultaneously.
Thanks for the information on the NiFe chemistry. I was not aware that they required regular watering. I did know that the electrolyte lasts for up to 30 years and then can be replaced.
How much charging can be done with the engine of your RV?
Hi MTS,
The batteries are not necessarily smaller with 24 volts--but they do work at 50% of the amp-hour draw for the same number of watts. That favors Peukert, of course. And of course as you mentioned 1/2 size cabling.
Hi Davydd,
If you have only 15 amps of shore power and wish to run the fridge, microwave and water heater all at the same time it becomes useful to draw from the battery bank. Particularly when it is -30 and there is no access to the shore power breaker box--which is often the situation I am in. I do use a watt meter and before I had the hybrid inverter I did load balance carefully. Now I don't have to do that any more. It was worth the extra cost to be able to do so.
I disagree totally about solar. For me as a former part time user it was the only way to extend the life of the battery bank. No shore power at any of the storage locations here. I was generator free for five years because I had a solar system.
Once the truly cold weather arrives it is far cheaper to go to a campground and use electric heat as opposed to running the generator and heating with propane. In the worst of the cold last year I was using 5400 watts and my class C was drifted in for four days. If I had been relying on propane I would have had a MAJOR problem refueling the fixed tank. I suppose I could have carried gasoline in a can for the generator. But it is only 2800 watts and while that may have prevented freeze ups it would certainly have been uncomfortable.
Hi Gerry,
I have read the Etrek page before. One of the more surprising things is their choice of a 5k Wagman inverter. Wagman is not very well thought of. Gotta love the 8 AGM batteries. 3500 watts equates to about 270 amps. But that is not a "pure" alternator, rather it is a 120 volt generator.
smoline wrote:
My current setup in addition to the 230 W solar array includes the two 6-volt AGM batteries that produce 190 Ah plus the Onan propane generator of 2.5 or 2.8 Kw (I forget which) and 1250 W inverter.
With that said, an increase to 400 Ah would be phenomenal; more than double what I currently have and certainly enough to run a coffee pot, toaster, CPAP machine, etc (albeit not all at the same time). However, conditioning or equalizing would not apply, as AGM batteries cannot (or should not) be equalized. I believe the wisest option would be to add more 6-volt AGM batteries to the current setup, or replace the current pair and start anew.
As with Lithium-Ion, I have also researched Edison (nickel iron, or NiFe) batteries not only for my RV, but also as a replacement for the battery bank which backs up the solar power for my home. NiFe batteries have many advantages, but (1) they are exorbitantly expensive and (2) they require watering, so need to be placed in a location convenient to adding electrolyte. As far as I know, they do not require equalization.
I greatly appreciate your level of detail, experience, and sage recommendations. Let's please keep this dialog going.
Steve
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