As you may know as a returning customer,  we have made the adjustment with a "plug in" to the shop which adjusts the prices depending how you pay. We had to them update the terms and conditions to reflect that the payment administration costs were a separate service. but we have also now had to align the "cash prices" as they were reduced from the "standard price" shown on the website.

Now for the batteries

RenewSolar last year put to tender the supply of battery packs, we do this now and them to ensure completion and lower the cost of batteries. The tenders are not just lowering prices but retaining quality and having what YOU want at the best price possible.
This means that your battery selection gets updated and we slot them into 3 categories, Budget, Mid range and top.

Budget would be your mid range batteries available from reputable suppliers. The idea here for us, is to cut as many corners as possible while retaining safety and functionality. all the frills are not there, but you get the essentials, capacity and reliability.

Our Mid range batteries are what you would find as the flag ship batteries from other companies. These have blue tooth wifi, brand names hardware and a little bit more on quality here as well as warranty and support.

The top range have more. Here we look at flag ship operation and over engineered solutions. A better managed battery and system which design and conformance as well as performance are considered. So you get extra. There would be higher capacity than stated, the setting will prolong the battery life and there is more hardware in the battery to ensure its operation and life span.

Warranty.
Budget battery will be basic, it will have 1 year manufacture warranty. no collect or return, and for faults past this period you may not be able to effect repair yourself, but you can send in hardware for repair and testing.

Mid range batteries often come with a  5 year warranty which includes capacity performance and collect and return service. Faults and testing are included in the warranty, but do check that they have the collect and return warranty as we have a bit of a wider range of batteries in the mid range section.

Top tier batteries come with a lot of support from us and the manufactures, we work together to ensure you don't have issues and can always rely on us both if you have any issues and questions for up to 10 years following your purchase.

No Warranty.
If you buy a battery that has no warranty, it does not mean you are buying at a big risk. RenewSolar is a ethical business; should your battery break or have an issue, you can contact us about it and you may find that you have a small easy, and cost effective repair. we offer diagnostic's and replacement parts as well as upgrades. and can fit them for you if required. This will be a charged service, but its wont be like taking a care to a garage ;)

Battery capacity.
All batteries should have the stated capacity as well our cells. should you find you do not, then contact us. Most of our battery supply chain offer a full refund. but before anyone says they capacity tested it and it was under, ensure that you know how to test and that you have calibrated testing equipment --- not some ebay / temu special.--

We do have test data and a lot of it when it comes to battery packs, they are pre tested by the manufacture and then tested before the build and then after. Cells are also matched in the process and so the likelihood that you have not got capacity is near zero. Budget tends to hit capacity, mid range is capacity and just over, and then premium is usually over capacity. in the premium battery range we may limit capacity in larger systems in order to retain life cycles of the battery, but you would still see the "stated capacity".

- Capacity drops
We are called out to test battery packs and problems from where fly by night solar companies install solar and batteries and then there are a lot of problems to fix. A common problem is a capacity drop.
And while I bash other companies, there are DIYers and special people who like to play around with settings and think they know best because they read on line...
The most common capacity fault is due to under charging or over charging. - Low voltage high current.

The second most fault is crap batteries and the wrong size.
Over using the batteries due to them being too small. reducing the life of the battery.
There are many "brands" that have got hyped, but are in fact terrible batteries, most people are now finding out how bad they were to listen to the "internet people".

There is of course cheap crap, which are usually ebay special or some one buying rubbish and selling it on ebay.  They often have used cells or faulty cells that work for a short time and as they are thrown together with a cheap BMS that cannot cope with the "problems" meaning that they have a short life.

There is of course a developed fault that can occur - balancer, lead circuit or even internal cell issues, they are fairly rare, but when shipping, they can happen.

In short.
All our batteries are a good quality and we price them fairly. we have a decent warranty process and we test and check everything. Problems let us know. You will wait around 30 days for a battery. buy with direct transfer and it cost less.

At the moment we are trying to address the shipped cost of batteries which accounts for over 30% of the cost of the battery! and we are also trialing and testing suppliers.

The primary drive behind the  battery storage is value for money and £/kW.  they have to function and also be reliable as well as follow up support.


Trade sanctions, arms embargoes, and other trade restrictions - GOV.UK
There are other "problems" within China, and also America which is leading to pricing and cost changes.
There is likely to be a rise of around 4% in the next coming days. which will effect all businesses across the world.

you may lose some Wh on the batteries to keep the great prices, or you will see variations on the batteries when you buy, you are reminded that you should contact us and direct pay if you want to see savings.

Battery Cycle Life

As you now should have an informed view you will want to share the load between batteries and also keep a higher state of charge, not use it all.
So if your daily use is 10Kwh of power, then a 10kwh battery is going to have a 100% DOD. that is 2000 cycles or 5.5 years.
Now lets say you have a 20Kwh battery, your DOD drops to 50% that becomes around 6000 cycles or 16.4 years.

it is important to work out the life and cost and value from the battery that you are thinking of buying. 
going back to Kwh over the life you can then work out if solar is value for money.
lets look at what they may provide you in terms of £ per KWH.

10kwh - 5.5 years 20,000 kWh £4,800
20kwh - 16.4 years 120,000 kWh £28,800

its seems a no brainer that having more battery makes more money savings, and if we use the £10kwh is £1500, then we can see what our costs will be and also the returns we can expect. There are some caveats to this, such as temperature control, and charge and discharge rates which will effect the battery life.
For the math I did use a unit price of £0.24. but I would assume that the cost of power  will rise over the next few years so that saving will increase.

The other consideration is that is just the cycles,  we have to consider charging costs, this may be solar, and if you are in the UK, you may find you are grid charging - so that could add a cost of between £0.05kwh and £0.11 depending on your provider. if you want to work the numbers yourself,  solar should be able to provide power for 275 days of the year, the remaining 90 days should be considered as grid charged.

The next consideration is current in and out.

Loading, or the current in and out of the battery will effect its life. we have posted up research into the charge and discharge power of the batteries and how the battery life is effected, needless to say a lower charge and discharge current is good.

The current out will be set by the inverter power and your loads.
Doing the math, is rather simple. You take the watts and divide this by the voltage of the battery.
for example 3kw is 62.5amps on a 48v system. (3000w \ 48v)

We apply the load current to the battery Ah rating, so our 200ah 10kwh battery would be discharged at .32c.
The C rate for batteries varies and this also concludes the rating (AH) of the cells, but the variable is 0.2c and 0.5c
That's  just under a quarter, and a half. Going beyond these will lower the AH of the cells.
That means lowers  the battery capacity.

What many of you will not know is that I have been internationally trading for decades, I know cultures and I'm a aerospace engineer and have 40+ years in Electronics and software. This skill set allows me to buy, barter and demand what I want, and I have high standards when it comes to investments and materials that represent me or rather any of my businesses.

It pretty easy to get cheap stuff, but it is a matter of actually getting down to a price point. if you try to go too low, you cut corners and quality drops but you have to be at the little sweet spot that gives the lowest price and everyone is happy, it s a bit communistic but I think it works.

when we started bringing in batteries, they had to be tested, and the whole chain had to be tested to ensure reliability, the problem was that we were able to bring in batteries that were a massive 70% lower cost that any one else. 
You should know what that means,  and if you don't, that is were you hit the "too good to be true".

One of the things that did happen was the price points became known across the whole sales company network and this thankfully drove down prices and for a good year to two we were still 50% less, the gaps is getting smaller and this only works when there are a good number of turn over. (high volume low profit).

The next big issue was that we could never hold stock.
When you have a great product they tend to sell out, so for a long time we would order stock. but that stock would sell even before it arrived in the UK.
One of the benefits was that it freed cash and lowered costs, so we had to address the short coming and do a little compromise. this let us push down the costs.

For example Frogstar 15kWh came behind us, there price point was £2500 ours has been £2200. I think the extra cost is in the sales and marketing as well as the storage, which is how they operate, but we managed to save £300 on the battery price and the delivery time is very slightly effected. - A week to 10 days.

Batteries by  — RenewSolar

Buying our batteries, you will always find quality hardware and configurations. if you do find a issue, you should be on us like wasps on honey.. as we will bee on the suppliers for a full explanation and you may find yourself getting some money back if not all your money back..

When you save money, you should keep in mind that you are buying the same thing as anyone else is selling - but I know ours are a little better. You are not paying less and getting less, unless you want to be less taken advantage of, we certainly do less of that..

New Suppliers.
New supply chains are difficult as a lot goes into the products that we sell. we have to buy them and then test them, which is a little more than what you think. we mystery shop,  and check up, so this means that we have to invest time and money into getting the hardware and specs as well as a good supplier, it can take a lot of negotiations.
We almost abuse the hardware so that it is the same as some users to ensure that the thing will take normal use and a little more. I do this so people do not  call me because there are issues. With the small margin it is not worth problems happening. So no problems for you, is no problems for me. That means we all win.
While we have a lot of contact from sellers, we actually have 3 suppliers of all our batteries.
We do take a review of what is on offer and see if any seller causes themselves to be of interest and then the quality and then demands start over. We have not had any issues from any of our batteries, and people who see the test results cant believe the data. ( lets say the results make all those videos look like children playing in rubbish)

Ironing out the kinks.
The company  was looking for advice on bringing these to market as they do represent good value and are two quality cells. The packs have different issues which are checked and rebuilt or replaced so that they work again. this means that there is variable costs and time in recycling the packs and cells for use in home power as well as cases and BMS systems.
Costing the battery packs as there is some work involved here, this will be announced on our shop. You would be saving around 40% on your home storage.

We are yet to set out the battery format, and yes this is UK based business.

The bottom price "truck" battery is a ABS case with terminals, maybe a meter of some sort, but they function as a lead acid drop in. for those with LA batteries this may be "no real change" but depending on the installation location ( and withstanding the new rules) they may not be practical. We did come across  some nice metal cases. which are smaller but they did not use prismatic cells, though apparently they did in the bigger ones. they also have an Anderson connection, which was a 50 amp connection.... for a 100amp output!  not ideal, but that depends on the use case.

Cells are down in price as Im sure you know, so that bare bones of a battery is NOT expensive, but may factor the shipping which can be costly. trying to find a UK battery case is a pain and I have looked into having one made.