I just finished a Samlex pure sine wave PST 3000-12 inverter install. I ran 00/2 cables because that was recommended in the user manual. I added a Renogy 30 amp transfer switch with the charger wired to the shore power connections so the charger stays off when shore power is off. It is practically next to the battery compartment under the dinette seat. I also installed the remote at the entry wall so I can see the readings without bending over like with reading the Victron meter (when not using Bluetooth) or the surge protector which I ordered without the remote by accident. So my first test was to run the microwave for 1 minute. I was kind of shocked to see the time remaining plunge from 9 hrs to 27 min in power left after only 1 minute. The 14.6 capable batteries were not fully charged reading 13.37 volts at start. Not sure why they were at that level as they are on shore power so the progressive dynamics 9160L should have them a bit higher. The voltage dropped to 12.87 in a minute. The Victron reads 98% charge but only 27 min remaining power. Maybe there is something wrong with my meter settings. Start:End after 1 minute of microwave power used:Does this amount of power draw seem about right for this inverter?

It shows that your battery bank (as entered in AH for capacity at the 20hr rate) will only last half an hour at 124 amps draw. After the MW has run its five minutes or whatever. the battery bank will bounce back quite a ways and still give you lots of time at ordinary amp loads like 10 amps for the furnace and a light.Your idea of battery voltages seems muddled. Your converter is set at 14.6 but the battery will take time to reach that voltage (Bulk Stage) then it is still not full. Now it stays at 14.6 with amps tapering until the battery is full. Now you drop that voltage to 13.6 for floating.

Right I may be muddled. I have read that explanation of battery charge and I must not fully understand it. The RV is usually plugged in to a 20 amp outlet with a 40ft outdoor extension cord. I think it’s a 14ga. So since it’s been constantly plugged in the charger should be in float mode and the battery somewhere between 13.8 and 14.6. I believe 13.8 is the highest voltage I’ve seen on the meter. I started the inverter just after disconnecting shore power and the meter only read 13.37 which seems a little low. 27 min left using the microwave would be great but the time left was dropping like crazy while the micro was on. From 9 hours to 27 min in a minute. I guess I should test again using the microwave until the battery power drops below11 amps. I thought that I could use the microwave with the inverter for short bursts of time without pulling that much power.

Your 9160L converter will keep the whole Rv at 14.6 when on shore power. the battery voltage will drop to its voltage that goes with being full once the converter is disconnected That is 13.6ish for an LFP.The monitor does not know how long you plan to run the MW so it is playing catch-up the whole time for time remaining, so you see that fast drop in time remaining the longer you run the MW.Seems like it is all behaving as it should. If you intend to be on shore power very long, you might consider shutting off the converter and only use it to recharge the battery as required. LFPs don't like to be on that 14.6 float for long periods. You still want 12v in the rig. You can use the battery for that or else get a second converter that floats at 13.6 and just use the 9160L when you need to bring the LFP to full.PD has a newer version of that converter that has a 13.6v float stage for LFPs.You can run the MW in bursts so your battery does not hit bottom all in one go. Some recovery between bursts is good.

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.The 125A draw is in the ballpark for a microwave, the AH consumed is reasonable for a 1 minute draw. I suspect that the display is calculating looking at the voltage drop over time and going from full charge and then drawing a high load for a short period of time the voltage tapered faster than it will over time hence messing up the remaining time.I think you will get a better indication by running the microwave for at least 5 minutes, better 10 minutes and see what it shows for remaining time. It could still be in the 30 minute range with a 200AH + battery bank

I still recommend 400+ amp hours for an inverter of that size. Victron seems correct. Although is it set for LFP? If set to lead-acid the Peukert calculation will reduce the expected capacity a bit faster. Did I miss the battery set up?Otherwise seems normal.Could be the photo angle but the ventilation seems a bit tight.

Samlex Inverter Power Draw Question | Good Sam Community

63 Replies

BFL13
Explorer II
Jul 08, 2021
Your 9160L converter will keep the whole Rv at 14.6 when on shore power. the battery voltage will drop to its voltage that goes with being full once the converter is disconnected That is 13.6ish for an LFP.

The monitor does not know how long you plan to run the MW so it is playing catch-up the whole time for time remaining, so you see that fast drop in time remaining the longer you run the MW.

Seems like it is all behaving as it should. If you intend to be on shore power very long, you might consider shutting off the converter and only use it to recharge the battery as required. LFPs don't like to be on that 14.6 float for long periods. You still want 12v in the rig. You can use the battery for that or else get a second converter that floats at 13.6 and just use the 9160L when you need to bring the LFP to full.

PD has a newer version of that converter that has a 13.6v float stage for LFPs.

You can run the MW in bursts so your battery does not hit bottom all in one go. Some recovery between bursts is good.
EMD360
Explorer
Jul 08, 2021
Right I may be muddled. I have read that explanation of battery charge and I must not fully understand it. The RV is usually plugged in to a 20 amp outlet with a 40ft outdoor extension cord. I think it’s a 14ga. So since it’s been constantly plugged in the charger should be in float mode and the battery somewhere between 13.8 and 14.6. I believe 13.8 is the highest voltage I’ve seen on the meter. I started the inverter just after disconnecting shore power and the meter only read 13.37 which seems a little low.
27 min left using the microwave would be great but the time left was dropping like crazy while the micro was on. From 9 hours to 27 min in a minute. I guess I should test again using the microwave until the battery power drops below11 amps. I thought that I could use the microwave with the inverter for short bursts of time without pulling that much power.
BFL13
Explorer II
Jul 08, 2021
It shows that your battery bank (as entered in AH for capacity at the 20hr rate) will only last half an hour at 124 amps draw. After the MW has run its five minutes or whatever. the battery bank will bounce back quite a ways and still give you lots of time at ordinary amp loads like 10 amps for the furnace and a light.

Your idea of battery voltages seems muddled. Your converter is set at 14.6 but the battery will take time to reach that voltage (Bulk Stage) then it is still not full. Now it stays at 14.6 with amps tapering until the battery is full. Now you drop that voltage to 13.6 for floating.

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Samlex Inverter Power Draw Question

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