I use the following "colour coding" for ATF - translucent red is fresh - opaque red is normal used - brown needs changing - and black is probably too late.

But many modern cars don't have a dipstick for the ATF anymore so not easy to look at the colour.

I would get the battery tested before getting involved with any expensive gearbox repairs.

Thanks for the reply. I don't use the car on a daily basis and if I do the journey is only local 30-40 mile round trip. Had a new battery 1 yr ago and battery recharged about a month ago after no start and low battery voltage show. Souds like journeys not sufficient to maintain full battery charge. Battery is removed for recharges- not able to run cable for in car recharge. Apart from the hassle is there any danger of system damage with boost starting/ battery removal proving terminals are disconnected/ connected correctly.