13W solar charger

http://forum.a8parts.co.uk/attachmen...1&d=1472036846

This is what happens with mains charger on drive if you have more than 1 user and that other user drives away without spotting a cable.

http://forum.a8parts.co.uk/attachmen...1&d=1556304369

http://forum.a8parts.co.uk/attachmen...1&d=1556990458

So folks, looks like it could be a Yuasa Silver battery problem maybe (thanks for the info).

I have had the car aprox 3 years and have had 3 brand new Yuasa Silver batteries on it in that time. I did have a current drain issue early on in my ownership which took me 18 months to get around to fixing. I just assumed this was why I was destroying batteries. My latest one has lasted about 8 months now and will still start and run the car OK but is needing more and more frequent external charges.

I know lead acid batteries don't like to be stood with a slow discharge so I just put it down to an inevitable consequence of how I use my car.

I'm gonna replace it with a Bosch S5 013. I know I will see a significant improvement initially as a new battery will perform well (usually) for the first couple of months. I'll let you know how it goes.

On my original point. Are there any issue with connecting 2 batteries to the same car in parallel? I am itching to give it a try before I get rid of the Yuasa but certainly don't want to bugger anything up.

My gut feeling is that if we can do this to jump a car with a flat battery then I should be OK. Does it not just make two 100ah batteries into one big 200ah battery?

Or....... Is this a case of a little knowledge being a dangerous thing?

Yuasa Silver caused me a huge amount of problems and also thought there was a problem elsewhere in the car.

Could not leave it for a few weeks without it going flat, new battery now and all those problems have gone.

No issues as long as both batteries are healthy and similar. You don't want a battery on it's last legs together with a new battery. It might be OK but I would not risk bad battery dragging the good one down. Also calcium, silver, AGM batteries seem to have a bit higher voltage so paired with plain lead battery they would charge/discharge at different rates.

I'm gonna shelve the idea of hooking up two batteries and just go for a new Bosch. I'll see how that goes.

After doing some research it is clearly OK to connect batteries together in parallel as we do regularly on HGVs, electric fork truck etc but some guidelines have to be followed.

1. The batteries should be of a similar age. This is to ensure a balanced discharge rate.

2. Batteries ideally should be of the same manufacturer. Same reason as above.

3. Batteries must be of the same capacity otherwise the lower capacity one will fully charge before the higher capacity one. This will then lead it to overcharge.

4. Ideally, as a safety precaution, the link cables between the batteries should be fused. This is incase one of the batteries developes an internal short. This will then potentially draw a massive current from the good battery. This may then damage the good battery also and even worse, if the link cables heat up, could become a fire risk.

5. (The real killer for me) Once the batteries have been connected together they will establish a state of "equalisation". It is recommended to charge the batteries (whilst still connected together) from a single charge source in order to help maintain this state.

Clearly point 5 renders my win win obsolete. No point in having a system that takes twice as long to discharge but then twice as long to recharge.

I feel like I have over thought this one a little bit. Maybe I need to find something else to worry about 🤔

Thanks ainarssems, you called it just slightly before I did 👍

How's the car going by the way, any progress on the gearbox?

No progress as I have been busy with other things. I bought a set of 16" wheels from A4 to go on it so that I can keep 19" Carlsson wheels, cats are coming off as they have £340-350 scrap value, probably take out radio, good battery, floormats, maybe some other bits then rest goes to scrapyard.


http://forum.a8parts.co.uk/attachmen...1&d=1572081551

:-(

Have you spoken to Prestige about it? At least if they take it an AHC engine can be saved.

At 1000 dollars probably not what most would want to spend on a battery but i love the restart idea thats built in, genius if you ask me.

https://antigravitybatteries.com/pro...tive/ag-h8-rs/