Good Sam Club Open Roads Forum: Tech Issues: Samlex Inverter Power Draw Question
Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Tech Issues

Open Roads Forum  >  Tech Issues

 > Samlex Inverter Power Draw Question

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 7  
Prev  |  Next
EMD360

Arvada, CO

Senior Member

Joined: 01/18/2010

View Profile



Good Sam RV Club Member


Posted: 07/08/21 08:28am Link  |  Quote  |  Print  |  Notify Moderator

I knew I could count on the big 3 to help me out. Not many people have this level of knowledge! I was just shocked to see that quick decline but I really understand 3tons explanation. And BFL13 also stated it in a clear way. The meter was just racing to keep up with the high demand. The bigger test would be to somehow continue a high load until the battery charge shuts off the inverter. Maybe the air conditioner. Waiting to hear from pianotuna though I know he’s not a lithium convert. But thank you to the rest who gave advice too.
I have the new version of the PD charger/converter. So the bulk charge at 14.6 does drop to a maintenance charge. I know I don’t have quite enough battery power for the inverter. But to run the microwave I needed 20 amp capability. 2000 watt inverters are only 15 amps.
For lithium batteries apparently you can throw away all you know about depletion for lead acids. That’s one reason I invested in them for the new RV. That’s why the other equipment is best replaced too. And I added the Renogy DC to DC charger for the alternator charging. Although I’m not convinced it is necessary. So it’s rather an expensive investment for just 210 ah rating. I’m counting on the 10 years some folks give it.
I did a test for my trolling motor battery box that I equipped with 3 20 amp lithiums. The batteries lasted over 19 hours with a 300 watt inverter, an electric clock, and a 75 watt light bulb. I tested the load and 60 amp hours should have lasted 24 hours. So there was a limit of about 80% depletion but we have not moved that battery meter below 100% with over an hour scooting around a lake. I didn’t watch the meter on the battery box so I’m not sure how fast the voltage dropped. It of course doesn’t have the time left reading. https://blog.twinsprings.com/2021/05/06/lithium-battery-test/
As far as Peukert’s law I’m not sure it’s something I will ever understand. (See above my muddled state on charging). Start with those formulas and I’m lost. Luckily the Victron has a long explanation of how their meter accounts for it. So let the electronics handle it! I have the meter set to most of the recommendations in the manual. I downgraded the battery capacity a little to 200 amps and increased the depletion level a bit. I think at 11 volts.
The upshot seems to be that I could use more battery power. The manual suggests 3 100 ah batteries as a minimum, 4 would be better. But I have limited room in the battery box. As it was I had to search for 100 ah batteries that would fit the small space. I have yet to test this with solar attached. I have a 200 watt portable panel. I’m thinking of adding a more permanent solar system to the roof. I’m not against using the generator of course. I just wanted a silent system for my warm milk at night etc.
Finally there is the issue of ventilation. I did crowd the box in the dinette seat. I’m thinking if it goes over temp I can add a grate to the side of dinette back. I added a grate under the fridge for the charger.
Thanks for the help. I need to not get so concerned about the time left and run it heavily until my batteries deplete to 11 volts. At least I can find out what the air conditioner draws. I had no intention of running the air conditioner with it of course.
By the way the Samlex is more expensive than the Renogy 3000 but It was recommended by experts that I respect and so I paid about double the cost of the Renogy.
This is the place to learn how to do complicated upgrades and check their operation that is for sure.


2018 Minnie Winnie 25b New to us 3/2021
Former Rental Owners Club #137
2003 Itasca Spirit 22e 2009-2021


ktmrfs

Portland, Oregon

Senior Member

Joined: 06/22/2005

View Profile


Offline
Posted: 07/08/21 08:34am Link  |  Quote  |  Print  |  Notify Moderator

theoldwizard1 wrote:

ktmrfs wrote:

batteries 12V in parallel, or GC2? GC2 do NOT like high current draw, way to much internal resistance so the inverter will kick out on low voltage pretty quick.

12V, assume you have at least 2, they (a) share the current, so each battery supplies 1/2 the load current unlike a GC2 pair where each battery must supply total load current and (b) have much lower internal resistance, hence less voltage drop with high current load.

I disagree completely !

Golf cart batteries are designed specifically to handle "high" loads and at 125A that is only 1/2C ! A pair of GC-2 batteries will live longer than a pair of 12V marine/RV batteries and cost less !



GC2 have many advantages, and can handle hundreds of cycles down to 25% SOC, but high current draw is NOT repeat NOT an advantage nor something GC2 do well. Myself and several other posters to this thread have seen the voltage drop and how quick a inverter will drop out when drawing 100A from a pair of GC2's.

Even trojan will tell you if you want high current draw use their 12 deep discharge. Thick plates and few of them do NOT play well with high current draw.


2011 Keystone Outback 295RE
2004 14' bikehauler with full living quarters
2015.5 Denali 4x4 CC/SB Duramax/Allison
2004.5 Silverado 4x4 CC/SB Duramax/Allison passed on to our Son!


EMD360

Arvada, CO

Senior Member

Joined: 01/18/2010

View Profile



Good Sam RV Club Member


Posted: 07/08/21 08:42am Link  |  Quote  |  Print  |  Notify Moderator

GC batteries are too large for my space anyway. I had more room in the old RV and could fit two group 27 batteries. But I ended up using only one group 29 because I burned them out too quickly. I tried Walmart SLA batteries and they didn’t last more than a season or two. I tried Autozone marine and kept losing one cell. Finally went back to Interstate and sold the rig with one group 29 rather new inside. I even tried used agm batteries and a double battery bank with a blue sea switch but they only lasted a season or two. Thus my willingness to invest in lithium batteries.

3 tons

NV.

Senior Member

Joined: 03/13/2009

View Profile


Offline
Posted: 07/08/21 09:17am Link  |  Quote  |  Print  |  Notify Moderator

Microwaves are relatively cheap…It makes little sense to try and run a stick house 1500w microwave from an battery starved inverter when a 800-850w works perfectly well in a camper…

3 tons

ktmrfs

Portland, Oregon

Senior Member

Joined: 06/22/2005

View Profile


Offline
Posted: 07/08/21 09:43am Link  |  Quote  |  Print  |  Notify Moderator

3 tons wrote:

Microwaves are relatively cheap…It makes little sense to try and run a stick house 1500w microwave from an battery starved inverter when a 800-850w works perfectly well in a camper…

3 tons


if your shopping for a new microwave for the RV get a panasonic true inverter microwave. doesn't cycle between 0 and 100%, but stays at a fixed % you set and at 50% power will do most of what you want but draw about 1/2 the full power current, Works great with an inverter setup. Doesn't take twice as long at 50%, maybe 25% longer

3 tons

NV.

Senior Member

Joined: 03/13/2009

View Profile


Offline
Posted: 07/08/21 09:54am Link  |  Quote  |  Print  |  Notify Moderator

ktmrfs wrote:

3 tons wrote:

Microwaves are relatively cheap…It makes little sense to try and run a stick house 1500w microwave from an battery starved inverter when a 800-850w works perfectly well in a camper…

3 tons


if your shopping for a new microwave for the RV get a panasonic true inverter microwave. doesn't cycle between 0 and 100%, but stays at a fixed % you set and at 50% power will do most of what you want but draw about 1/2 the full power current, Works great with an inverter setup. Doesn't take twice as long at 50%, maybe 25% longer


Agreed 100% [emoticon]

3 tons

pianotuna

Regina, SK, Canada

Senior Member

Joined: 12/18/2004

View Profile


Offline
Posted: 07/08/21 02:41pm Link  |  Quote  |  Print  |  Notify Moderator

EMD360 wrote:

The bigger test would be to somehow continue a high load until the battery charge shuts off the inverter. Maybe the air conditioner. Waiting to hear from pianotuna though I know he’s not a lithium convert.


Hi EMD360.

Thanks for the compliment.

Li are EXCELLENT batteries but they do require more fuss than some folks care to admit, especially if one wants a high number of cycles.

Because I rv in extreme cold, only one formulation of Li would suit my needs--and it is 4 times as expensive as lifepo4.

DO add the cooling grill Li batteries do not love heat. I'd go farther and add a computer fan on a thermostat.

The big inverter is a good plan.

I would not use the air conditioner for the load test. Use a 15 amp heater instead--if the heater dies it is no big deal. If the compressor on the air conditioner goes out--well who wants that sort of trouble?

I think, from what I read that your system is behaving normally. Peukert hardly applies to Li at normal loads.


Regards, Don
My ride is a 28 foot Class C, 256 watts solar, soon to have SiO2 batteries, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

3 tons

NV.

Senior Member

Joined: 03/13/2009

View Profile


Offline
Posted: 07/08/21 03:29pm Link  |  Quote  |  Print  |  Notify Moderator

PT, says “ Li are EXCELLENT batteries but they do require more fuss than some folks care to admit, especially if one wants a high number of cycles.”

This comment is a prime example of why I choose not to comment on a battery type that (I admittedly…) have absolutely no experience with (e.g. SiO2’s), and points to the importance of reader discernment…

3 tons

time2roll

Southern California

Senior Member

Joined: 03/21/2005

View Profile



Good Sam RV Club Member


Posted: 07/08/21 03:33pm Link  |  Quote  |  Print  |  Notify Moderator

pianotuna wrote:

Li are EXCELLENT batteries but they do require more fuss than some folks care to admit, especially if one wants a high number of cycles.
The fuss is all during the set up. Then they just work.


2001 F150 SuperCrew
2006 Keystone Springdale 249FWBHLS
675w Solar pictures back up

pianotuna

Regina, SK, Canada

Senior Member

Joined: 12/18/2004

View Profile


Offline
Posted: 07/08/21 05:03pm Link  |  Quote  |  Print  |  Notify Moderator

3 tons,

Your comments help the OP in what manner?

time2roll, Yes they work--where it is not -30 or if in a full time situation where there is a way to keep them warm.

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 7  
Prev  |  Next

Open Roads Forum  >  Tech Issues

 > Samlex Inverter Power Draw Question
Search:   Advanced Search

Search only in Tech Issues


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2021 CWI, Inc. © 2021 Good Sam Enterprises, LLC. All Rights Reserved.