System can't keep up after upgrades and reconfiguration

[syclonedriver]

I was thinking about this last night. So your plugging your shore power cable into the inverter, are you running the charger/converter for the original house bank?

How are you charging the original house bank?

 

[syclonedriver]

Full disclosure - I refilled until I ran out of distilled water.

Yesterday I drove into town and picked up some more water. I filled all cells. For four 6v batteries it took almost six cups of water....

As long as the plates were not uncovered you are probably fine.

 

[dixonge]

I was thinking about this last night. So your plugging your shore power cable into the inverter, are you running the charger/converter for the original house bank?

How are you charging the original house bank?

When I flip the inverter on I have to make sure two different things are not used:
1- The fridge has to be set to Gas only - if it's on automatic, it will try to use the AC from the inverter, which drains the batteries very quickly!
2- The house batteries have to be disconnected using the switch by the door, otherwise they try to charge from the solar battery bank.

Original house batteries are charged infrequently when running genny for maintenance, and from the alternator at least once a week when we drive to town for dumping the tanks, refilling water, supplies, etc. Normally 40-60 miles round trip.

 

[syclonedriver]

1 & 2 make complete sense, power management.

How difficult would it be to parallel the banks using a voltage sensing relay or an echo charger. When the original house bank is charged (above a set voltage) the relay parallels the to banks and the secondary bank chargers via the alternator/shore power/generator. It's done frequently in the marine world. I use a dual bank charger and and a transistor based battery isolater on my sailboat. It's the factory setup and it work for me, I don't live on the boat yet.

 

[dixonge]

How difficult would it be to parallel the banks using a voltage sensing relay or an echo charger. When the original house bank is charged (above a set voltage) the relay parallels the to banks and the secondary bank chargers via the alternator/shore power/generator. It's done frequently in the marine world. I use a dual bank charger and and a transistor based battery isolater on my sailboat. It's the factory setup and it work for me, I don't live on the boat yet.

Everything I can find online seems to indicate that an echo charger is usually used to take shore power or genny charging from the house batteries and extend it on to the engine starter battery. I assume you are talking about re-routing this to the battery bank instead? The main problem I can see for this is wiring. Would need around 25 feet of cable to connect from house batteries to solar battery bank.

 

[syclonedriver]

Yes, use the echo charger to charge the second house bank from the original. You shouldn't need huge cable as long as you don't let the second bank become deeply discharged. Fuse the cable appropriately. Use a quality voltage sensing type relay.

 

[dixonge]

Got a nice full day of sun yesterday. Turned off the inverter most of the day. Battery charging was 12.5 hours in bulk, 22 minutes in Absorption, maybe 1 minute of float. Somewhere in there I tried to manually equalize but there wasn't enough sun left and my max voltage was 14.55v. Might try again today.

Checked SG after the sun was down. Everything still low. Newer pair of batteries had maybe slightly better SG? Either way, things don't seem to be improving much. Starting to price a full battery pack replacement...

 

[syclonedriver]

Got a nice full day of sun yesterday. Turned off the inverter most of the day. Battery charging was 12.5 hours in bulk, 22 minutes in Absorption, maybe 1 minute of float. Somewhere in there I tried to manually equalize but there wasn't enough sun left and my max voltage was 14.55v. Might try again today.

Checked SG after the sun was down. Everything still low. Newer pair of batteries had maybe slightly better SG? Either way, things don't seem to be improving much. Starting to price a full battery pack replacement...

Don't give up yet, they might surprise you.
I would be more concerned about the batteries performance then their SG, it's good to have the data though.

I'm at little surprised that you still haven't bought or borrowed a charger and ran the generator.

 

[dixonge]

Don't give up yet, they might surprise you.
I would be more concerned about the batteries performance then their SG, it's good to have the data though.

I'm at little surprised that you still haven't bought or borrowed a charger and ran the generator.

I am Boondocking in the forest. Tomorrow is next scheduled run into town.

 

[dixonge]

SG levels are all slightly improved after today’s Equalization.

 

[Sgt Raven]

Full disclosure - I refilled until I ran out of distilled water.

Yesterday I drove into town and picked up some more water. I filled all cells. For four 6v batteries it took almost six cups of water....

You may already have one. This style battery water bottle makes filling them real easy. I used them in Gas Stations when I was a teen. Bought one for myself, for my own batteries.

https://www.amazon.com/Cycle-Battery-Water-Filler-Bottle/dp/B00NB808P0

ETA: I always replaced batteries in groups, when I owned big rig trucks. Mix old and new, the old ones drag the new ones down. That was the theory, at least. Or battery companies wanted to sell more.

 

[dixonge]

SG levels still very weak.

2 slightly older batteries: avg 1.150
2 newer batteries: avg 1.210

This is not good

 

[Wellbuilt]

dix you are killing the battery’s , you just don’t have enough power coming in , buying new battery’s is just a temporary fix. Sg of 1.210

 

[Sgt Raven]

dix you are killing the battery’s , you just don’t have enough power coming in , buying new battery’s is just a temporary fix. Sg of 1.210

I don't know, his system was keeping up, until he changed the SCC.

 

[Wellbuilt]

dix you are killing the battery’s , you just don’t have enough power coming in , buying new battery’s is just a temporary fix.
Sg of 1.210 A bad number. But 1.150 is a dead battery .
At this point you need to get some juice in them now .
Find some sun and try to charge just 2 batteries and see if the sg improves .
They can come back but you have to do it now.

 

[Wellbuilt]

I don't know, his system was keeping up, until he changed the SCC.

he has been using the battery’s since June thats three sunny months , now he is getting less power .
I’m sure the battery’s have been getting dragged down and its a coincidence That he changed the controler and it’s getting worse .
Panels laying flat do ok in the mid summer sun but the power drops off fast at the end of August .
If he is seeing 20 amps I think that is about the power you get from 400watt laying flat in Augusta
battery manufacturer like to see 10% rate of charge , that would be 46 amps @ 12 volt .
So the battery capacity has been walked down a little every day over the last 3 months

 

[dixonge]

yeah, plus lack of water didn't help. I agree with @Wellbuilt - sun angle dropping is revealing a power shortage.

So to get things up to 46-50amps, including winter in southern Arizona, it seems like I will need maybe a total of 800w of panel? Does that sound right?

 

[Sgt Raven]

Can you mount the panels in a way that they can be tilted towards the sun? How much extra room do you have? Maybe some extra panels you can hang on the side when you're parked. If I find the 400W I have now is not enough, I've thought about getting a couple more and either hang them on the side or ground mount them. I can plug them into my MPPT with Anderson Power Poles and a twin lead 10 AWG cable for them.

I have a 20' cable like this I can run it into where my SCC is. If I stick with two more panels with the same specs, my SCC will just see them as more of the same. Then I would have three pairs of two in series and then the 3 groups in parallel.

https://www.amazon.com/Valemo-Exten...g+solar+extension+cable&qid=1631249985&sr=8-6

 

[dixonge]

Can you mount the panels in a way that they can be tilted towards the sun? How much extra room do you have? Maybe some extra panels you can hang on the side when you're parked. If I find the 400W I have now is not enough, I've thought about getting a couple more and either hang them on the side or ground mount them. I can plug them into my MPPT with Anderson Power Poles and a twin lead 10 AWG cable for them.

I have a 20' cable like this I can run it into where my SCC is. If I stick with two more panels with the same specs, my SCC will just see them as more of the same. Then I would have three pairs of two in series and then the 3 groups in parallel.

https://www.amazon.com/Valemo-Exten...g+solar+extension+cable&qid=1631249985&sr=8-6

When I run the numbers using the 10% charge rate I end up at 552 watts. Adding two more panels just like I already have would give me 600 watts. My existing panels are in 2s2p configuration. Adding two more would be 2s3p? Three sets of two in serial, then all three sets paralleled together. I think. It seems like there are various pros/cons to keeping them portable.

Pros:
* Can tilt to sun and maximize watts, helping to offset the bad angle of the roof-mounted flat panels
* Don't have to mount more panels on the roof

Cons:
* all the usual issues w/ portable panels
* transportation - in the RV? (where?) or in the car? (between the mountain bikes?)
* How would I splice these in w/ the existing panels? All my existing mc4 connections are on the roof. A combiner in my battery compartment, I guess?

 

[Sgt Raven]

When I run the numbers using the 10% charge rate I end up at 552 watts. Adding two more panels just like I already have would give me 600 watts. My existing panels are in 2s2p configuration. Adding two more would be 2s3p? Three sets of two in serial, then all three sets paralleled together. I think. It seems like there are various pros/cons to keeping them portable.

Pros:
* Can tilt to sun and maximize watts, helping to offset the bad angle of the roof-mounted flat panels
* Don't have to mount more panels on the roof

Cons:
* all the usual issues w/ portable panels
* transportation - in the RV? (where?) or in the car? (between the mountain bikes?)
* How would I splice these in w/ the existing panels? All my existing mc4 connections are on the roof. A combiner in my battery compartment, I guess?

Don't combine them on the roof. For the two portable panels 10-12AWG leads and hook them into the circuit at or near the SCC. If you need to, put a small bus bar or terminal for all the solar and then run one set of wires to your SCC. Use the largest AWG your SCC will accept for that last connection. I don't care for them, but SAE plug/sockets are used a lot in the RV industry to give a plug in on a wall. You see them in the pre-wired Zamp solar setups.

A padded case for transporting a big screen TV would work good for a pair of solar panels and give them some protection. Something like this. You just have to find one that works with the size panels you're using. I'm assuming a pair of 100W panels.
https://www.amazon.com/dp/B01CVSXLK...olid=2D2ZSVCWGUFHS&psc=0&ref_=lv_ov_lig_dp_it

My SCC has 1/4" screws and uses ring terminals. My panels on the roof terminate at a 45A power pole set at the SCC. That way I can unplug them there. I'll stack a 2nd set of terminals to a 2nd set of 45A PPs. I may run 10AWG zip wire to the back of my topper on my pickup and plug in the portable panels there. I'm using Anderson Power Poles for all my 12V connections. 45A (12-10AWG), 75A (6AWG), and 120A (4AWG) versions. I'm color coding the 45A PPs, so it will be obvious what plugs in where. Like Blue/Black is my fridge/freezer circuit. Green is for every dedicated ground.