Out of car battery charging query
 

Many questions asked about this old chestnut but....
Due to being abroad several months of the year, the CDT is garaged. It has always been a problem for the battery being unused for about 3.5 months at a time. Previously I have to get a recovery service to start the car. This time around (March 2nd in the depths of snow) with a portable power pack (can’t get another vehicle to it) it would not, even when attaching my Lithium starter pack as well. The only solution was for a replacement battery. £100 lighter it started no problems.

I know about keeping it charged by several means but for various reasons of power supply and location it is not possible. I kept the old battery which was new when buying the car in October 2014.

I have an old 1970's Selmar Star battery charger of my Dad’s and am trying to tickle charge the Yuasa 3000 096 battery. It still seems to work but I have no instructions and the charger which is a bit basic having only an ammeter charging at about 1.5amps ( if that is what it means).
The battery does not display a green indicator, just black.

Am I wasting my time trying to charge this battery? It is getting on for 4 years old so would the the plates be too sulphated? Or, how many hours will it take to show a charge. I do not have any handheld devices to indicate anything.
Any thoughts please!

Such a charger is best consigned to the bin, unless you want to supervise it constantly during a charge - because it will keep on charging until a battery is wrecked. Whether it might recover your old battery, it is very unlikely indeed.

Buy a new, modern charger, which has a properly controlled output - one which falls back to a proper 13.5v maintenance mode is best, rather than one with a 13.8v output, which can cook a battery dry if left for months.

Lead Acid batteries hate not being used, a I understand it the plates calcify. The one on my Mower I need to discharge and charge a couple of times over winter otherwise its replacement time in the spring at £60 a pop!

So if its being left for a while it needs a good trickle conditioner/charger. You mention you can't get power to it easily (I think), how about a solar one? Though they're rather pathetic in the UK sunlight it would at least keep the trickle going. Solar cell on the garage roof and cable through to the car.

Thanks guys. It is as I thought. Bin it. Tried a solar panel one sometime ago, but didn't work and got rid of it. It is just too difficult to describe how the garage (not mine) is situated but any options just don't work unfortunately.
Many thanks for the replies.

Then take the battery out and home with you, it will not suffer much harm if brought up to a full charge every few months, if that is all you can manage. Worst case is being left connected to the car, because all modern cars do discharge their batteries if left connected by several milliamp.

... and leave it permanently connected to a C-tek ‘smart’ maintenance charger. The battery will last for years and be ready for action when you need it. I speak from experience.

Simon

OK, I'm not charging the 'old' battery anymore, as it probably is kaputt.
I take note of disconnecting the new battery. Regret for all manner of reasons I cannot use a smart charger or any other means of trickle charging. So next time coming soon I will disconnect the battery insitu.

Question; Will that be perfectly safe to do so?, as it will be disconnected for at least 3 months and that NO problems with ECU or other electrical bits will be affected?

I actually tried to disconnect it last time but could not budge the terminal, so will try a dummy run. Is it OK to just disconnect one terminal? Positive?
All sounds like silly questions but meddling with electrics well...
Thanks, Ray

The only possible problem is you might need a radio code. Your Engine ECU will likely forget its learned adjustments, if it does that, but within a few miles will relearn them.

DO NOT disconnect the positive, always the negative. If you remove a battery you should always disconnect the negative first, reconnect it last. The reason being that if you attempt it positive first/last, there is a risk of your shorting the battery +ve to earth via the spanner, with several hundred amps flowing through it.

NEGATIVE FIRST/ NEGATIVE LAST -always!

Thanks Harry. A nice definitive answer. :} Ray

In the OP's case, I suspect the batteries are going to keep getting killed by the deep cycling which is occurring due to non-use.

The most elegant solution would be to buy a high-capacity leisure battery and rig-up a 12v-12v intelligent maintenance charger.

The simplest way to achieve the above would be to purchase a high-efficiency pure sinewave 25W-50W inverter and 0.8A CTEK or Optimate maintenance charger.

It will just a matter of taking the leisure battery to the house once every months to 2 months to fully charge up and then leave it connected to the car for maintenance permanently.

This battery should do it nicely.

https://www.alpha-batteries.co.uk/23...yABEgI_P_D_BwE