Battery RIP?

[watercooled]

Yeah that is a fair point I should have mentioned about it possibly failing at a bad time. It's something I typically mention, and suggest at a minimum getting a free battery health check after charging and resting, as many garages offer them, but was interested to see what happened when you'd tried charging it as that was unlikely given the terminal voltage.

I disagree about the comment regarding AGM being unnecessary though - start-stop and smart charge systems can destroy cheap batteries very quickly and I have seen this happen, in far less than 6 years, even in a matter of months sometimes. In such systems, batteries should be replaced with as close to identical chemistry (e.g. EFB or AGM for stop-start), capacity and CCA rating as possible as this is what the BMS is calibrated for. The automated lookup systems I have used will typically be aware of this and not recommend standard batteries.

If the vehicle does have one of those systems (not necessarily just stop-start), then the BMS should also be reset when replacing the battery so it knows it isn't still using an aged battery. This can be done with an OBD tool but in some cases there's a button/pedal combination you can press to do it in the cabin.

[ik9000]

Luckily it's not stop-start (That's the thing where it turns itself of in queues of traffic and auto-starts when you hit the accelerator right?) so no worries there. I've ordered a Varta D15 silver which sounds ample to the task and slightly better CCA than before but nothing too crazy. <£70 delivered so better than I was fearing tbh as I had in mind car batteries were usually >£100 but then my friends probably just have expensive tastes in motors compared to my humble little runaround.

[watercooled]

That's about right for a standard battery TBH, you're looking more around the £100 mark for EFB and more again for AGM if the car requires them. And yeah, stop-start being the system where the engine cuts out and quickly restarts when you depress clutch/accelerator depending on transmission type.

It might still be worth checking if the car has a BMS (battery monitoring system) that needs resetting though.

Also just one last thing, some cars can drive or idle a bit weird for a few miles after a battery swap as it will lost what's in the computer's volatile memory. The manual for mine recommends 5 miles of 'varied driving' for it to relearn its variables.

[ik9000]

That's about right for a standard battery TBH, you're looking more around the £100 mark for EFB and more again for AGM if the car requires them. And yeah, stop-start being the system where the engine cuts out and quickly restarts when you depress clutch/accelerator depending on transmission type.

It might still be worth checking if the car has a BMS (battery monitoring system) that needs resetting though.

Also just one last thing, some cars can drive or idle a bit weird for a few miles after a battery swap as it will lost what's in the computer's volatile memory. The manual for mine recommends 5 miles of 'varied driving' for it to relearn its variables.

Now that could explain a lot. It'd been doing some weird sheet the last few journeys mostly on idle. It will be interesting to see if this makes any difference. I thought, given that the engine was running, that it shouldn't be battery related, but if the management systems themselves are unhappy, yes that could fit.

I don't think it has a BMS, but I will see if the manual says anything about one.

[philehidiot]

It's likely running on safe mode if it has lost the existing data. It's incredible what modern engines use in terms of data to make combustion as efficient as possible.

Indeed I didn't consider the charging / management system being configured to a particular type of battery. Someone I know put a lipo battery in his bike because it was "better and lighter". Don't bother asking how that went. He got better upper body strength from pushing, though.

Around £70 is about right. Odds are if someone is going on about car parts in the pub, they're looking at premium products. For a runaround you don't need that.

[DanceswithUnix]

Indeed I didn't consider the charging / management system being configured to a particular type of battery.

EFB/AGM batteries run at a higher voltage and charge differently than standard lead acid units, so you need to stick to the correct sort of battery. You can't trickle charge an AGM battery for example.

Bit late in this case, but another vote here for the Halfords batteries, one of the very few things they sell that I like. I tend to go for the Calcium tech ones, they do cost a bit more but last longer and are more resilient with occasional use.

My main reason for posting though, to try and avoid this happening again you need a way to top the battery charge up.

One of our cars now has a solar panel velcroed to the rear parcel shelf with leads going to the battery in the boot. Started with a puny 1.5W job that I got cheap from Maplins when it was closing down, which slowed the battery losing charge but just wasn't powerful enough. Just replaced it with a bigger (10W I think) panel I got from Amazon so hopefully that is one car that now won't ever go flat (though I'm not sure how much power the car alarm takes as well as the battery self discharge that has to be overcome).

For the others, I have https://www.amazon.co.uk/CTEK-MXS-5-...dp/B00FC42HAA/ to keep the batteries happy, an awesome bit of kit. The higher end models can handle all battery types and will test and try to recover iffy batteries, though it sounds like the original battery here is well beyond saving. The insides of those cells will have the plates shorted out with sulphate crystals making it impossible for those cells to actually charge.

The solar panel was about £30 (and I can't say how well it works yet), the conditioner is closer to £70 and if you have a driveway to charge the car on is awesome but expensive. I leave my kit car plugged into the CTEK all winter. It doesn't require the battery to be removed, monitors the battery voltage and when it has dropped 10% charges the battery back up to 100% and stops charging. That's way better for the battery than trickle charging.

[ik9000]

EFB/AGM batteries run at a higher voltage and charge differently than standard lead acid units, so you need to stick to the correct sort of battery. You can't trickle charge an AGM battery for example.

Bit late in this case, but another vote here for the Halfords batteries, one of the very few things they sell that I like. I tend to go for the Calcium tech ones, they do cost a bit more but last longer and are more resilient with occasional use.

My main reason for posting though, to try and avoid this happening again you need a way to top the battery charge up.

One of our cars now has a solar panel velcroed to the rear parcel shelf with leads going to the battery in the boot. Started with a puny 1.5W job that I got cheap from Maplins when it was closing down, which slowed the battery losing charge but just wasn't powerful enough. Just replaced it with a bigger (10W I think) panel I got from Amazon so hopefully that is one car that now won't ever go flat (though I'm not sure how much power the car alarm takes as well as the battery self discharge that has to be overcome).

For the others, I have https://www.amazon.co.uk/CTEK-MXS-5-...dp/B00FC42HAA/ to keep the batteries happy, an awesome bit of kit. The higher end models can handle all battery types and will test and try to recover iffy batteries, though it sounds like the original battery here is well beyond saving. The insides of those cells will have the plates shorted out with sulphate crystals making it impossible for those cells to actually charge.

The solar panel was about £30 (and I can't say how well it works yet), the conditioner is closer to £70 and if you have a driveway to charge the car on is awesome but expensive. I leave my kit car plugged into the CTEK all winter. It doesn't require the battery to be removed, monitors the battery voltage and when it has dropped 10% charges the battery back up to 100% and stops charging. That's way better for the battery than trickle charging.

how do you leave it connected? does it have to plug in from the mains? I'm not sure I'd be able to run a lead out to the car and leave it like that for long stretches at a time.

[watercooled]

For the solar ones, you just connect them up and leave them while the car is idle. I've been tempted to get one myself before today with the intention of connecting it through the cigarette lighter, but I think that gets disconnected a while after the car gets locked so I'd have to wire it up some other way.

@DanceswithUnix: FWIW I've measured standby consumption on my car with a clamp meter before today, IIRC after being locked and left for a while it drops to about 30mA. It's higher initially so to get an accurate reading I had to pop the bonnet, lock the car then come back 30 mins or so later to take a reading once everything had gone into its lower power state.

@ik9000: Regarding leaving it connected, it's not critical if it's not convenient. I also have a charger but don't use it as a trickle charger, just if the car has been idle for a while I'll connect it first thing in the morning and it will usually be topped off by the evening. I was doing it roughly every week or couple of weeks during the lockdown.

[DanceswithUnix]

how do you leave it connected? does it have to plug in from the mains? I'm not sure I'd be able to run a lead out to the car and leave it like that for long stretches at a time.

For the kit car, it stays in the garage for most of the winter, so in the dry and easy access to mains.

For the solar panel in the MX5, there is a hole in the parcel shelf from fitting a roll over bar to the chassis, so an easy cable route to the boot where the lead from the panel is clipped to the battery terminals.

I would put a panel on my everyday car, but although Alfa put a 12V utility feed in the boot the power switches off when the ignition is turned off so that's pretty hard to wire up.

[philehidiot]

I did once have a charging port on the side of my bike but found that riding every day I just don't need it.

Is the general concensus that if this is an infrequently used vehicle and if he's going to replace and then not use it regularly to charge / cycle the new battery, that a charger would be a good idea?

My opinion is that the existing one lasted ten years before failing. That's pretty decent and doesn't present a problem worth solving in my view. It's unlikely the car is going to be owned by the same person for another 6 or 7 years and so a charger seems like a cost that isn't going to give any practical benefit beyond ensuring the battery is in top condition when it goes in? In which case, I'd borrow a charger from someone for the one off initial use and take it from there.

[circuitmonkey]

I picked up a Noco Genius 1 for £30 couple weeks before lock down for my old car and it was fortuitous timing.

I picked the Noco as it has modes for lead acid and AGM so would work on all my cars, also picked up the Noco extension cable and a few hard mount kits with charge indicators that live under the bonnet.

Has kept all my cars nicely topped up in lock-down.

Being only 1 Amp it's not the fastest charger but knowing I'm not going to have a dead battery when I want to drive my car is nice

[ik9000]

that looks really good. presumably though it needs a mains plug to work so do you have to run leads from the house to the car?

New battery fitted today. Works a treat.

[circuitmonkey]

Indeed the Noco unit itself is like a walwart plug. It's plugged into the mains in the garage and runs under the door to the car

[DanceswithUnix]

Is the general concensus that if this is an infrequently used vehicle and if he's going to replace and then not use it regularly to charge / cycle the new battery, that a charger would be a good idea?

It was mentioned that the car hadn't been used for 3 months. That will kill the new battey, making a charger at the same price as the battery it would save at worse a break even cost. Or the car needs to be used every week.

[ik9000]

Indeed the Noco unit itself is like a walwart plug. It's plugged into the mains in the garage and runs under the door to the car

how long are the leads? I reckon I'd need 2m plus a bit extra to get down under the door and back up to the battery level, say 3-4m?

[circuitmonkey]

IIRC the unit itself has a 2m lead on it, the extension lead is 3m