question

Onwell Dzobo avatar image
Onwell Dzobo asked

victron gel batteries pop up and gassing

Hello team. One of my clients called me yesterday to notify me of a potential disaster on his offgrid victron Multiplus 24/3000/70-50 based solar system. the other components of the systems are a 250/70 Smart solar TR MPPT , 12* 310W solar panels and 10 by 10 by 12V,230AH gel batteries wired in series/parallel. the inverter room was smelling and gassing and on checking the system, THEY realised 4 batteries had popped up open , and the other 6 swollen and showing signs of a popping up too sooner rather than later. some adjacent batteries had actually got stuck to each other most probably due to heating , we had to apply considerable force to seperate them. no battery stand was on site , the batteries where stacked on top of each other in 2 rows of 5 seperated by two wooden blanks between top and bottom row.it is the space between these two wooden planks that had the most swelling. i replaced the entire battery bank with 6 brand new rolls surrette s12-220AE batterries. Please assist possible causes of such a failure and how it can be avoided in the future .

Cyrix Battery Combiner
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2 Answers
Margreet Leeftink (Victron Energy Staff) avatar image
Margreet Leeftink (Victron Energy Staff) answered ·

When a large amount of batteries are connected in series/parallel they are a myriad of things that can go wrong. We usually do not recommend to parallel more than 2 or 3 series strings of batteries, 5 is way too much. If a bigger battery bank is need another type of battery needs to be chosen.

Th problems that you are having is highly likely due to battery cabling issues, the way they were wired, not able to get rid of heat and battery unbalance.

For more information on all this, please read the wiring unlimited book and also have a look at the battery training in Victron professional.

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Pieter Boomsma avatar image
Pieter Boomsma answered ·

Are those MPPT's set to the right voltage? It looks a bit like the batteries were being overcharged. Maybe you can let your customer check the charging voltage of the MPPT.

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