Keeping battery charged whilst isolating

[QQ17]

I tried to start my car yesterday afternoon for the first time in a week. Much clicking, but it wouldn't turn over and I got the Stop/Start fault error message. Suspecting it was the battery, I put it on a trickle charge for a few hours, and then it started first time, as it did again this morning. As part of a major service in May 2018 the Nissan garage replaced the battery under warranty, telling me that the original was a Renault one, and that they weren't very good!

I shall be following the AA advice above, but wondered if an occasional trickle charge, whilst the battery was still in and connected, would do any harm?

[calnorth]

In theory it shouldn't harm but not much is known about the use of the Battery by the cars system when the Ignition is off. It does perform certain low power monitoring functions. In my experience charging in situ has not been a problem although the last FIAMM Battery did not fully charge thus failed later on formal test.

If I were to do it today I'd disconnect the car Battery -ve terminal. And keep a frequent eye on the charging process. 3 to 4 hours "full charge" should be enough per 10 days...say. All depends on battery quality really. Ability to regain adequate capacity.

The aim of the exercise is to not allow the Battery to completely discharge. Some chargers may not be able to recover the Battery and ultimately the Battery could be damaged. Replacement now becomes a big issue...most likely.

[QQ17]

Many thanks calnorth. If I disconnect the battery's negative terminal to charge it, once reconnected I'd presumably have to reset the clock, radio settings, saved sat nav settings etc etc?

[calnorth]

Not sure but that would be the worst case. I suspect the settings are saved. I reset my Connecta Box on Batt change anyway...for fun?