Safety of granny chargers over time

You have a dedicated circuit, so no problem.

I think the socket might melt overtime. EV charging is continuous load. Even high power appliances like electric stoves or water boilers are drawing around 8A for 30-60 mins Max. With charging you are drawing 8A for 7 hrs. Just try to make sure the socket can handle the load for that long.

Good point. I'll see if I can find sockets designed for that, or just change them every few months.

You should be fine. Personally I put over 1MWh through a granny charger connected through an extension lead and nothing got hot, failed or otherwise. Just make sure you check it regularly for overheating.

I've run my granny charger on 10A on an extension lead (industrial and rated for 10A continuous load) every day for 3.5yrs now between my (non-byd) hybrid and my wife's ev (only been DC charged once in its life). It has never gotten hot or tripped the breaker (on the same circuit as the washer/dryer/garage fridge) If the wiring and plugs etc are all designed for it then you should have no issues. The electrician is either misinformed (many are when it comes to EV/PHEV sadly) or simply looking for an upsell with some extra work hoping people dont do the math. Either way - faster chargers have their time and place but if you dont need it, they can be an unnecessary expense.

Short answer: if you need to ask this question it's better to, at least, review the whole electricity infrastructure of your house by an electrician. Long answer: as some users already pointed in their answers, the issue here is the long time with high consumption, usually between 8A and 16A depending on the country you bought the car. The main issue is the temperature generated by the consumption of charger, and the weak elements are diverse across the elements involved: \- The service entrance cable. \- The wiring in the breaker panel. \- The wire section of the dedicated line. \- The quality of the socket where you are plugging the charger. \- The power of the charger itself. \- The age of the electricity infrastructure of your house. And even the country is important as different countries started to strength the requirements at different times. In general the main issue is that until few years ago the regulations for houses where not designed to host a really high consumption devices for hours. Having a dedicated line is fine, of course, but depending on the wire section it can be an issue or not. In my case, for example, the socket line was performing fine, but the connection of the service entrance to the breaker panel was not strong enough and it quickly started to burn. Fortunately I found the the fault before it caused a fire and could solve the problem before a real risk happened, but seems like with a few more charging sessions the fire would happened, burning my breaker panel and putting my family at risk. **IMPORTANT**: my electricity infrastructure was certified and approved by both an authorized electrician and the electricity company. So from my point of view and my own experience it's almost mandatory to check the whole house wiring. A wallbox is not not mandatory, of course, but the wiring checking and proper accommodation is, even if you're charging occasionally.

The BYD one is certified to standards in Australia; so as long as your wiring isn't crap, there's no issue. Sounds more like an upsell. There's plenty of people using the granny chargers over long periods without issue.

Thank you, it’s great to hear from someone who has been using the granny charger for so long. The electrician may have a conflict of interest, given that it’s an expensive job, and he may also be biased since he’s had more than a handful of customers with burnt-out chargers. But your responses have alleviated my concerns, and I’m much more confident in my setup now.

Thank you for your input. I live in Brazil, and my charger is rated at 13 amps. The house’s electrical system is new (4 years old) and there are two grounding points. The breaker panel is new, and there’s a dedicated 32-amp circuit breaker for it. New 4 mm wiring as well. That said, I’ll keep what you said in mind, specially regarding the service entrance cable, and look into whether my power company offers any kind of certification/inspection service.

Most of the burnt out/damaged chargers i know of locally have been due to water damage - often the plug going into the vehicle is water proof and fine to be outdoors, however the plug and box going to the house wiring usually need to be kept dry. Alot also comes down to the circuit and power supply in your country/area. If the wiring and fuse/breaker arent designed for the loading or the power supply (grid power) is prone to fluctuations then it could cause issues.

Hey Man, im also in Brazil and just bought a king. What did you end up settling with? Tô numa situação parecida e queria uma atualização. Se puder me conta aí!

Considerando tudo o que li e ouvi, decidi continuar usando o carregador portátil mesmo. Um ponto é que aqui no Reddit os carregadores deles parecem ser de 8 a 10A, enquanto os nossos são de 13 A. Mesmo assim, pelo custo, o wallbox não compensa. Acho que o maior risco seria o próprio carregador portátil queimar. Se isso acontecer, aí sim eu compraria um wallbox. Estou carregando em casa há pouco tempo, então ainda tenho algumas inseguranças por causa do relato do eletricista. Por exemplo, não tenho coragem de deixar carregando durante a noite. Mas, no meu caso, também não é necessário. O que pretendo fazer ainda é uma vistoria/laudo da instalação elétrica da minha casa, para ficar mais tranquilo. Até lá, estou usando uma tomada exclusiva, que vai direto para o quadro, com disjuntor próprio e fiação nova. Até agora, não vi oscilação nem aquecimento em nada. A fiação da minha casa é nova, inclusive a parte externa (da rede para o relógio e do relógio para o quadro), o que também me dá mais segurança. O que eu não faria é colocar em qualquer tomada, e nem usar em instalações antigas.