Batteries and charge controllers by new layman

[Island Man]

Hi Everybody. I bought an island 25 years ago and put a small panel with small CC and 60 amp battery without any knowledge just for lights and water pump on an old caravan. Then added one more small panel and battery. Children got older so tv required. I then contacted a supplier who installed 2x140 watt panels through a morningstar CC and added a 500 amp Rolls battery. Cabin was built, Grandchildren arrived, more cabins were built so added 4 Sharp 180 watt panels through a Flexmax 60 + 2 more Rolls batteries and Outback 12v inverter/charger with 2 Kw generator. Hot water, fridges and cooking is by bottled gas and heat by unlimited supply of timber. Water pumped to tanks from lake. I will be 70 on Monday and I find the task of carting gas from mainland not so easy any more so I want to use efficient fridges.
My supplier sold me 4 Sharp 235 watt panels telling me to connect them to the Flexmax 60. We installed them on the roof but at this point, before connecting them, I decided to research this subject and realised that this was wrong and that I needed an additional CC like Flexmax 80 to cope with the wattage. I also intend to add 1 more battery to balance things.
APOLOGIES FOR THE LENGHT OF THIS.
I have concerns when I read the problems encountered when setting up a master slave with the Flexmax and their interaction.
2 x 2v cells were found to be faulty and with some persuading Rolls are replacing these although they told me it was wrong to connect batteries of a different age. How else could I expand my system?
As a layman I would appreciate opinions on the above as I can't rely on my supplier.
Cheers

[Sunking]

2 x 2v cells were found to be faulty and with some persuading Rolls are replacing these although they told me it was wrong to connect batteries of a different age. How else could I expand my system?

You got me a bit lost but assume this is your only question.

Roll told you correctly, you should not be mixing old batteries with new. The old batteries will drag down the new batteries and make them old in a hurry. Batteries are replaced, not added on to. If you need an upgrade you get rid of the old and buy new larger batteries. Batteries are only made to last about 5 years for top of the line Rolls 5000 series. .

[Island Man]

You got me a bit lost but assume this is your only question.

Roll told you correctly, you should not be mixing old batteries with new. The old batteries will drag down the new batteries and make them old in a hurry. Batteries are replaced, not added on to. If you need an upgrade you get rid of the old and buy new larger batteries. Batteries are only made to last about 5 years for top of the line Rolls 5000 series. .

I accept the logic that old should not be connected to new. However it makes expanding storage very expensive. I would also disagree about 5 years as Rolls give a 10 year guarantee.

[Sunking]

Might want to take a look closer at Rolls Warranty.

3000 series is 18 month full after that up to 48 prorated.
4000 series is 24 months full, after 60 months prorated.
5000 series is 36 months full, after 120 months prorated.

Been working with large scale telecom battery plants for over 30 years and if you go beyond full replacement period you will have to provide detailed PM documentation noting voltages temperatures, and specific gravity readings for each month in service. Otherwise they will not honor it. Worked with thousands of 5000 series batteries and none have tested 80% capacity after 5 years. What you look for in battery life is the Full Replacement warranty to get an idea how long they will really last. A babied set of 5000 series you might get 6 to 7 years. After 5 to 7 years the scrap salvage price is worth more than prorated warranty. When you choose to go off grid that is the consequence you suffer is never ending battery replacements at ever increasing prices.

[Island Man]

Rolls

Yes you are right. I did the tests requested by Rolls and they accepted that two of the cells had failed. They prorated for 66 months and are sending two new cells. Reading your reply I now question why I should accept their offer. It seems a bit futile replacing the cells attaching them to old ones. Should I not demand a whole new battery prorated?
I didn't choose to go off grid as I had no choice.
It's good to have this forum as there are people like yourself with a wealth of experience who are prepared to take the time to share.
Thank you.

[Island Man]

Batteries

SunKing. Would you give me your opinion on the following.
Based on your previous advice I am not now going to add a further battery. I think I should milk the 3 x 5000 series batteries until they die and then replace them. My supplier provided me with the RB-12CS11PS 503ah Rolls. We use the holiday island for about 6 separate weeks in the summer and at any time we are drawing from 20 - 30 amps. I am trying to allow for a prolonged period of dull weather say for a maximum of 7 days. When I get the outback flexmax 80 the panels will total approx. 2000 watts. Am I using the right batteries. Having learnt a bit more recently I intended to set the relay so that there is a load for say an hour so that the batteries are working when I am not there. There is also the winter period to consider when the security cameras are the only load drawing 1.5 amps. Should I be using the AGM sealed batteries as I am not there to service them for long periods.

[solarside]

A babied set of 5000 series you might get 6 to 7 years. After 5 to 7 years the scrap salvage price is worth more than prorated warranty. When you choose to go off grid that is the consequence you suffer is never ending battery replacements at ever increasing prices.

I agree. Anyone that has ever dealt with prorating understands this, it's just a marketing gimmick.

You can baby them and still have early problems. I say if you paid for them, use them for all they are worth and hope for the best.

I accept the logic that old should not be connected to new. However it makes expanding storage very expensive.

It's always a problem replacing failed batteries in a big battery bank situation, if you can go grid tie you should, you could go with a preheat electric hot water tank with some of your solar panels and reduce your bottled gas use, I know that grid tie not possible on the island, but maybe start making your system into smaller independent systems so you could swap batteries around and have more choices.

[Island Man]

T
Thanks solarside. What does "baby them" mean

[Sunking]

T
Thanks solarside. What does "baby them" mean

Kep them cool, dry,never discharged more than 50%, and well maintained with proper preventative maintenance.

[Island Man]

Inverter/charger

Thanks SunKing. Dry?

Have read your very informative battery design tuition. I should be 24v or 48v but am stuck with 12v as my Outback inverter/charger is 12v. A new 24v is £1500+. Maybe when I replace my batteries I will go the whole hog.
I wish I had taken the time to interest myself in this subject years ago. I think I know more now than my supplier.

[Sunking]

Thanks SunKing. Dry?

The tops and hardware clean, dry, and not letting them boil over.

Do not be too hard on the dealers. They are not technicians or engineers, they are salesman first and foremost. Their primary interest and loyalty is to sell you something as frequently as possible. Unfortunately the only party who puts your interest first is YOU.

[Island Man]

The tops and hardware clean, dry, and not letting them boil over.

Do not be too hard on the dealers. They are not technicians or engineers, they are salesman first and foremost. Their primary interest and loyalty is to sell you something as frequently as possible. Unfortunately the only party who puts your interest first is YOU.

That's ok but if I had added 960 watts, 194 voc to the mx60 which already had 720 watts it would have been dangerous or at best expensive. I should have started research sooner but spilt milk

[Sunking]

That's ok but if I had added 960 watts, 194 voc to the mx60 which already had 720 watts it would have been dangerous or at best expensive. I should have started research sooner but spilt milk

Not sure I follow you here. There would be no reason why you would have to exceed the MX60 maximum input voltage. It is just a matter of arranging the panels in combination of series/parallel to obtain the most efficient voltage operation to stay under the max limit of 150 volts.

Now as far as exceeding the power input you made a huge mistake from the start selecting a 12 volt RV system. The MX 60 has a maximum panel input of:

800 watts @ 12 volt battery
1600 watts @ 24 volt battery
3200 watts @ 48 volt battery
4000 watts @ 60 volt battery

If you started with 12 volts, you screwed yourself from the get go. Any home based system should be at least 48 volts from the start. They are far more efficient and less expensive to install and operate.

[Island Man]

SunKing. With 1680 watts from panels installed including panels purchased,erected and not yet connected I would have to go 48 volts to utilise only the mx60. That's 4 new batteries + a new inverter/ charger.
As I said before we only use the place on average for 6 x 1 week periods each year.
The new 235 watt panels have each a temp. adjusted voc of 40.8 so I am thinking that I could use these 2 x 2 in series paralleled through a flexmax 80 with a hub4 connected to the mx60 so I can stay at 12v and still use my expensive outback 12v inverter/charger. I also wondered would I be better cutting off the panels from the batteries during the 5 month winter period when I can't service them or use a relay with a load connected to make them work.
By the way you don't need to keep reminding me that I made a mistake 25 years ago. I was too busy working 12 hours a day for my family to learn this stuff.
I would value very much your opinion on the 2 items above.

[Sunking]

The new 235 watt panels have each a temp. adjusted voc of 40.8 so I am thinking that I could use these 2 x 2 in series paralleled through a flexmax 80 with a hub4 connected to the mx60 so I can stay at 12v and still use my expensive outback 12v inverter/charger.

2 x 2 and 4 in parallel are fine.

I also wondered would I be better cutting off the panels from the batteries during the 5 month winter period when I can't service them or use a relay with a load connected to make them work.

No I would not. I would disable the EQ mode if set and leave on panel connected to keep the batteries charged up. 5 months is just way too long to leave the batteries set without a float charge. Just make sure they are topped up with water and all loads disconnected.