Hello All!

Been a while. I miss y'all, and the XJS group too!
This old house. Its been 3 years of working weekends and whenever I can on it. I almost never drive, commute in the city with public transportation.

Sadly, the Jags have been sitting, and something like neglected, but still running and driving. But rarely.

I WASTED a battery in the XJS (an AGM) and I CANNOT believe the cost of new, these days.

So, my question. When it comes to the XK8s and XKRs does using a solar battery tender scramble or wreak havoc on the cars all too sensitive electrics IF you leave the battery connected with a solar trickle charger?
I mean, will it not allow the BPM and other electrics NOT go to "sleep" after the few minutes when it drops down to minimal millivolts? Or create some other squirrly problems? What about the need to DISCON when driving?
The idea is to place one of those "smart" AMAZON chargers on the back dash and just leave it. But it could be a PITA if it has to be disconnected and battery reconnected every time, if you know what I mean?
I'm trying to figure out what to do and how to go about it

I'd be very grateful for anyone willing to share their thoughts, experiences, workarounds or whatever advice is offered up.

In advance, many thanks
J

 

The solar car battery charging panels I see on Amazon are around 20W, which means that at 14V charging, they deliver just over 1A. At that level of charge, it's best to keep the car out of direct sunlight to avoid damaging the paint. But if it has to be in the sun, it won't do much harm to the car's electronics, since the battery "softens" the current sent by the low-power solar charging system (which already has a controller).
What I'm not sure about is whether this will be an attractive target for thieves, and we might come back to find the window broken. If it's for a vehicle parked in a garage, since it's not in direct sunlight, even if it's well-lit, the charge level will drop, making it less risky. Let us know how it goes if you install it and if it maintains the battery's charge level. Ah, leaving 20W (maximum) at 14V connected won't make any difference; the alternator itself will provide more voltage, and that's what the solar panel regulator is for (which will be protected in both directions).
Now, I wouldn't install it (for now), since there's no "wireless" charging and I wouldn't want extra cables. The last battery was from 2018 (I haven't seen the month), but I did perform maintenance every three months or less (recharging and checking the level; once I left the car unlocked and after a few days it discharged). Oh, I don't know if our car's charging system is compatible with AGM batteries. In fact, the Ctek charger I have (a basic one) has four charging modes (car, motorcycle, AGM, and regeneration). If the AGM charging system were the same as the basic ones (I don't mean standard, since all cars now have start-stop), it wouldn't be an option. I see no need to use an AGM battery. The new battery is a Varta 100 Ah in an L5 case, it costs almost half as much as an equivalent AGM battery.

 

I have a cheap solar panel on my boat to keep the battery topped up and it works well - no more flat batteries.

A small panel won't affect the electronics on the Jaguar and won't affect whether they go to sleep or not.

 

I carry an emergency jump starter. In fact, after the battery died, I used this jump starter to start the car. I had previously charged it with a Ctek charger; it didn't show any errors after a full charge in recovery mode, but it still wouldn't start. So, when the battery is almost dead, it can't start such a large engine (it can open and close the car, roll down the windows, and even start my little 1.1-liter Citroën C2). This means that, in addition to carrying a charged battery, it's advisable to keep an emergency jump starter somewhere in the car or boat (mine works for gasoline engines up to 8 liters, or diesel engines up to 4 liters). On land, you can manage with a cell phone, but on a boat, I understand that you need to be even more prepared.
I installed the new battery myself yesterday afternoon. The whole thing is recent.

 

1 I’ve been using AGM batteries for the 8 1/2 years of ownership. If there’s an issue with them not charging I would’ve noticed it by now.

the advantage to the AGM batteries is longevity. They will outlast a regular battery by years. In the long run, they are cheaper.

2 I routinely park in the full sun for hours at a time, days at a time when traveling cross country. If the southwest USA sun intensity doesn’t affect the paint here, I doubt it would be a problem anywhere. (Saudi owners let me know if you have issues there).

I removed the engine compartment sound deadening pad over 8 years ago. The friction of the pad degraded the paint on the underside of the hood somewhat. Some day I’m going to see if some waxing compound can clean it up. But in the meantime, there’s been no downside to removing the pad. No paint change on either side of the hood / bonnet. Not that was expecting any problems. There’s millions (billions ?) of cars that never had such a pad. And none of them have heat related paint damage.

Z

 

Yes, I was about to buy an AGM battery, but in the end I decided on a standard one after seeing the CTEK charger. Obviously, it charges the battery; the active components are the same. But when our cars were manufactured, they didn't have AGM batteries installed. Newer cars with start-stop systems have additional sensors to monitor battery consumption and charging (you even have to register the new battery in the car's system). All the reviews I read say that AGM batteries perform better, but in the end, I didn't go for it. Obviously, your AGM battery is already better than my standard one (but it has to last 14 years to compensate for mine, which only lasted almost 8).

Like I said, they say they're better, but I haven't decided yet:

https://www.varta-automotive.com/kno...battery-better
My first XK8 (second-hand) had one side lighter than the other (including the wheel emblems, it was very noticeable there). You had to look closely, though, which meant that when it had been parked outside, it had been in the sun on that side much more often. Sunlight isn't good for paint or upholstery (especially the headliner). My current car's paint was fine (except for a small scratch I had repaired), as were the wheels center caps. I don't think a solar battery charger is worth it because of the installation and the hassle of having it on the dashboard or in the back (but I liked the idea).

 

I have three of these and they work great. Never had an issue. I know it is not solar but just wanted to put it out there

 

These days, a conventional battery that lasts 8 years is doing pretty good. From the online posts I read on a couple of vintage forums, there’s a lot of agreement and discontent regarding the slide in battery quality.

I hate to say it, but even the best AGM batteries (Optima, are you listening ?) aren’t as good as they were pre 2000. But the prices keep going up of course.



Z

 

Ordinary lead acid work great and can last 8 years on these cars if you either have properly shutting down systems or a ctek-type device. Really no need to pay for an expensive AGM battery.

 

For some reason I didnt get alerts that folks had responded! Thank you all!

Awesome Man, thank you for nailing my question.
My fear is/was that with the tender charging, battery cables still connected, the tender would prevent the car from going into sleep mode - or cause some other chaos.

I rarely drive these days but its nice to know that when I do go jump in I can leave the tender leads connected and just unplug the panel and throw it in the back seat - and quickly replug it after.

So, I'll put one on order and HOPE for the best.

Thank you all for your input!