Reconditioned Batteries

[stevelcd]

I'm looking for 5x 200aH batteries for a solar application on a tight budget. Anyone know of a reliable supplier whom they can recommend?

[Guest]

Tell us more, for tight budget and batteries are a dangerous combination. 

[stevelcd]

This is for pensioner friends - they have 8x100aH batteries of which 4 are very soft. It runs on an AXpert 5kva inverter with 4 x 320watt panels. They have a forget it and leave it attitude and the system has been installed for 3 years with the original batteries. They only found there was a problem when the system went to bypass when they plugged in the 3000watt kettle. Their budget is 10-12k for replacement batteries (which can be recon).

I was thinking to remove the dud batteries and wiring just the good 4 batteries up in the meanwhile.

I was thinking of a solution with 4 x 200aH batteries 

 

[Guest]

Sjoe. Tough one.

Let me get this right. They now need new batteries to boil water?

That kettle, they save not a cent if it is on solar. The cost of the initial batteries and inverter made the ROI zero in my opinion on the kettle. Put the kettle on Eskom say I.

Pensioners tend to be very light on power. 

Depending on their age a solar system does not really make sense in my opinion. Tested it with my parents. Issue comes even more to the forefront when the system will outlast them versus the money staying in their investment account earning interest, to pay their low usage of Eskom power.

Solar system comes last on that sum when batteries need replacement. 

Recon (conned) batteries I frown upon with unbelieving eyes. If you buy batteries for recon attempt at their going lead prices to try, by all means go ahead. 

Here is what I would do, seeing as they have the system already:
Put the stuff that costs money, the 24/7 loads, on solar, and spec the batteries from that.
If they don't need to spend any money, good! If they have to, as little as possible.

So lets start at what their 24/7 load is like, and see if remaining batteries can handle that?

 

 

[___]

1 hour ago, stevelcd said:

Their budget is 10-12k for replacement batteries

For around 20k you can get Trojan T105RE batteries. Much better battery. But the forget-it-and-leave-it attitude is not going to work well with flooded batteries.

[pilotfish]

6 hours ago, stevelcd said:

I was thinking to remove the dud batteries and wiring just the good 4 batteries up in the meanwhile.

Are all the batteries the same age? I wouldn't mix 3 year old batteries with new batteries, you will wind up killing your new batt's very quickly. If you plan on using just the good string of batt's in the mean time until the budget improves then this is a viable option.

 

6 hours ago, stevelcd said:

I was thinking of a solution with 4 x 200aH batteries 

This would be a good solution (but see below) - but you should add an HA-02 battery balancer. The damaged string in the old bank probably came about as a result of 1 battery going "out of sync" which resulted in the other batteries needing to pick up the slack and failing as a result. The HA-02 will help to prevent this from happening to the new batteries.

6 hours ago, stevelcd said:

It runs on an AXpert 5kva inverter with 4 x 320watt panels.

4 x 320w panels is a good balance for 4x 100Ah batteries but is not enough for 4x 200Ah batteries.

Your 1280W PV array will produce around 6kWh on a good day and who knows what on a bad day. Your 4x 200Ah batts can theoretically supply about 10kWh at 100% discharge or about 5kWh at 50% discharge (which you should try not to exceed). 5kWh at an estimated 85% charge efficiency will require the full 6kWh provided by the panel to fully recharge the batteries, leaving nothing available for direct consumption.

In practice the Axpert will supply loads directly as required during the day meaning that there is not enough capacity available to properly recharge the batteries. Leaving batteries partially charged on a consistent basis will lead to sulphation and premature failure. This is also a very likely contributor to the original battery failure.

So the sad truth is that if you plan to go back to a 200Ah battery bank then I would recommend doubling the size of your PV array. The budget for this project (DIY) should be around R30k.

 

[stevelcd]

All the batteries  are of the same age 3 years old excis 102aH - 8 of them.

I managed to source 4 x 200aH gel batteries fivestar 200aH to replace the excis

[pilotfish]

11 hours ago, stevelcd said:

I managed to source 4 x 200aH gel batteries fivestar 200aH to replace the excis

Marketing materiel (10 - 15 year life with 36mnth warranty) and price seem good, If you can get hold of a data sheet for the batteries please post it here.