New LiFePO4 Set up for my Camper

[Iceman218]

Received 4 CATL 271 3.2 cells from @Michael B Caro last month and finally have some success to post. Per help on the forum, I also purchased a Smart Daly 4s 250 amp BMS and a Progressive Dynamics 45 amp LiFePO4 charger. Still awaiting a wake up button from a link on this site, but other than having to use the charger to wake the BMS once in a while, it is working well.

The issue was the ability to operate a hair dryer and I think you can understand the importance of this item to my relationship with my wife. With my frost damaged 2 6V Flooded cells, I could get three minutes of hair dryer operation. But that was actually suggesting my 1000 watt inverter might not be a road block. Well, with my cells properly top balanced then configured with the BMS, it now operates the hair dryer just fine from any outlet in the camper. So the 1000W inverter that was standard content in my GeoPro may prove to be enough unless I want to operate more. I was of the believe that a 2000 Watt inverter might be needed.

I have 2 100W solar panels and do understand it would take days for the 10 amps they can produce in Michigan to ever charge up a depleted 271 ah battery, at least that now has become my weak link. There is room on the roof for 600 watts and I also plan on getting an EPEVER 30 amp MPPT solar charger (since I only seem to be able to get 5 amps per panel) but welcome your thoughts on this set up.

 

[snoobler]

Received 4 CATL 271 3.2 cells from @Michael B Caro last month and finally have some success to post. Per help on the forum, I also purchased a Smart Daly 4s 250 amp BMS and a Progressive Dynamics 45 amp LiFePO4 charger. Still awaiting a wake up button from a link on this site, but other than having to use the charger to wake the BMS once in a while, it is working well.

The issue was the ability to operate a hair dryer and I think you can understand the importance of this item to my relationship with my wife. With my frost damaged 2 6V Flooded cells, I could get three minutes of hair dryer operation. But that was actually suggesting my 1000 watt inverter might not be a road block. Well, with my cells properly top balanced then configured with the BMS, it now operates the hair dryer just fine from any outlet in the camper. So the 1000W inverter that was standard content in my GeoPro may prove to be enough unless I want to operate more. I was of the believe that a 2000 Watt inverter might be needed.

I have 2 100W solar panels and do understand it would take days for the 10 amps they can produce in Michigan to ever charge up a depleted 271 ah battery, at least that now has become my weak link. There is room on the roof for 600 watts and I also plan on getting an EPEVER 30 amp MPPT solar charger (since I only seem to be able to get 5 amps per panel) but welcome your thoughts on this set up.

Sounds good. Worth noting your daily PV harvest to get an idea of how much energy you can use daily. Those panels in great sun appropriately tilted might get 1kWh/day - that's about 50 minutes hair dryer use.

271Ah*3.2V*4 = 3468Wh

Assuming peak panel performance, 3.5 days to charge provided you don't use anything for 3.5 days.

I didn't see any mention of a battery monitor. If you truly care about knowing the condition of your battery, they're priceless. Will recommends a couple on his site. They're well worth it.

I didn't see any mention of the existing solar controller. If it's only a 10A charger, that would explain why you're not getting more than 5A from each panel.

If rooftop protrusions/items cause regular panel shading, you might consider a small array of flexible panels that you can quickly deploy:

Cheap Dual Flex Panel Mobile/Tilting Stand

Here’s a super lightweight and cheap adjustable stand design that I use for 100w flex panel pairs. Each unit costs

diysolarforum.com

Flexible panels aren't generally recommended due to their poor life, but if you're only using them when you need them and not leaving them mounted, you should get your money's worth.

A 30A controller is only good for about 30A * 14V = 420W. I would consider a 50A if you're considering going to 600W (and you should).

 

[Iceman218]

I do have a nice battery monitor. You are correct that they are essential as voltage alone is meaningless.

My current solar controller is a GoPower 30A PWM. Think that is not the best and appreciate your 50A recommendation as my experience is limited and buying the correct upgrade is important.

No sure on panel tilting as my camper orientation is variable with all points of the compass possible. So adding more roof panels rather than less roof panels and tilting for similar expense needs consideration.

But if I do a mobile two panel setup, that link would work well.

Appreciate your input @snoobler

 

[Alphacarina]

For 600 watts of solar, I would buy their 40 amp controller. The difference in price is very small and sometimes it pays in the long run to oversize some components, even if you're wiring them in series/parallel and 30 looks like 'enough'. I originally bought that same 30 and then when I saw 28 amps coming from my 450 watts I returned it and bought the 40. I've seen 31 and 32 amps now on a good sunny day. You may one day drive your RV to a sunnier clime

Don

 

[snoobler]

I do have a nice battery monitor. You are correct that they are essential as voltage alone is meaningless.

My current solar controller is a GoPower 30A PWM. Think that is not the best and appreciate your 50A recommendation as my experience is limited and buying the correct upgrade is important.

No sure on panel tilting as my camper orientation is variable with all points of the compass possible. So adding more roof panels rather than less roof panels and tilting for similar expense needs consideration.

But if I do a mobile two panel setup, that link would work well.

Appreciate your input @snoobler

Glad you have a battery monitor. Which one?

Rooftop orientation doesn't matter if the panels are flat on the roof unless roof protrusions cause shading issues that can be eliminated with a different orientation. That's why I recommended the lightweight deployable array - 2X 100W panels can outperform the same amount on your roof by a good measure, especially if you're willing to change the orientation of the panels 2-4 times/day. Important to look for flexible panels with ETFE coating and 5+ year manufacturing warranty and 20+ year performance warranty. The ones without the ETFE coating are the ones that don't last long.

Another advantage of a deployable array is if you want shading for the camper for comfort, but you still want solar collection.

30A for current panels should be fine, but PWM is limiting. They work by shorting the panel to battery voltage, so your peak power is about 80% in perfect conditions (it gets worse with lower battery voltages) vs. MPPT which permits true 100% (in perfect conditions). In less than perfect conditions, the gap narrows somewhat, but PWM will nearly always pull in less for any given condition.

 

[Freep]

There is room on the roof for 600 watts and I also plan on getting an EPEVER 30 amp MPPT solar charger (since I only seem to be able to get 5 amps per panel) but welcome your thoughts on this set up.

I have a 271 battery in my truck camper with a 2000 watt inverter, 600 watts of panels and DC-DC converter. Being able to use the microwave without firing up the generator is life changing. Using the AC plugs while boondocking without having to worry about draining the battery is freeing.

 

[Mia]

I have a 271 battery in my truck camper with a 2000 watt inverter, 600 watts of panels and DC-DC converter. Being able to use the microwave without firing up the generator is life changing. Using the AC plugs while boondocking without having to worry about draining the battery is freeing.

We too would like that ability to use the microwave and such without firing up a generator.

What amp version of the MPPT do you have?
(We currently have a 30 amp)

Also, just curious, if it is a 2k pure sine wave combo inverter charger (or is it just the basic inverter?)

We too have a dc to dc charger (40 amp) - along with -

2 x 100 aHr FLA batteries - and -

2 x 100 solar panels currently

(We also have 2 additional panels we can take from our camp and install to double the solar power generation from 200 to 400 Watts of panels, but wasn’t sure it was needed with the current battery bank capabilities….)

 

[Freep]

What amp version of the MPPT do you have?
(We currently have a 30 amp)

Also, just curious, if it is a 2k pure sine wave combo inverter charger (or is it just the basic inverter?)

We too have a dc to dc charger (40 amp) - along with -

2 x 100 aHr FLA batteries - and -

2 x 100 solar panels currently

(We also have 2 additional panels we can take from our camp and install to double the solar power generation from 200 to 400 Watts of panels, but wasn’t sure it was needed with the current battery bank capabilities….)

The MPPT is a Victron 100/30
DC-DC is a Victron Orion-TR non-isolated 12/12/30
The inverter is GoWise 2000 Watt pure sine wave, it is not a combo.

The LiFePo4 battery is the key to our happiness. It takes up less room, has more energy storage, can charge quickly and handles the occasional heavy loads with no issues.

 

[Iceman218]

Glad you have a battery monitor. Which one?

Rooftop orientation doesn't matter if the panels are flat on the roof unless roof protrusions cause shading issues that can be eliminated with a different orientation. That's why I recommended the lightweight deployable array - 2X 100W panels can outperform the same amount on your roof by a good measure, especially if you're willing to change the orientation of the panels 2-4 times/day. Important to look for flexible panels with ETFE coating and 5+ year manufacturing warranty and 20+ year performance warranty. The ones without the ETFE coating are the ones that don't last long.

Another advantage of a deployable array is if you want shading for the camper for comfort, but you still want solar collection.

30A for current panels should be fine, but PWM is limiting. They work by shorting the panel to battery voltage, so your peak power is about 80% in perfect conditions (it gets worse with lower battery voltages) vs. MPPT which permits true 100% (in perfect conditions). In less than perfect conditions, the gap narrows somewhat, but PWM will nearly always pull in less for any given condition.

My monitor is the

AiLi Voltmeter Ammeter Voltage Current Meter Voltmeter Ammeter 100V 350A​

Seems to be doing okay but limited experience with the new battery.

Will look at both 40 and 50 Amp solar controllers. Is there one brand that is superior for the mobile user?

I do need to do a trial on our Cuisinart Oven /Air Fryer before deciding if I need a bigger inverter. The GoWise brand seems to get good reviews.

 

[snoobler]

Decent budget battery monitor for LFP.

Victron is superior, but you pay for that.

 

[Freep]

I do need to do a trial on our Cuisinart Oven /Air Fryer before deciding if I need a bigger inverter. The GoWise brand seems to get good reviews.

You will want to do an energy audit for that oven. It seems to me that it would drain a battery pretty quickly. But I could be very wrong. Best to know for sure.