IS250 stalled after ignition

[Musi]

Hi Forum Members. Would be grateful for your thoughts.  I have a 55 IS250. In the last 12 months it’s had a new Battery and spark plugs. 2 weeks ago I filled up with E10 before realising I needed the E5. When the E10 was run down I filled up with E5 (cost an extra £8 to do so by the way). I drove the beloved old boy for about 50 miles. All OK. Left it parked up for 3 days and then started it up to do a short trip. Upon ignition it started perfectly as always. Then the engine and Battery warning lights came on at the same time. Within seconds the car cut out as I was coming down the driveway. After 5 attempts the car started up and was fine. 
 

Any thoughts as to cause? Was the E5 / E10 the cause or a red herring? Would welcome your thoughts generally and whether I should take him in for a check up?

best regards all. 
 

musi 

[ColinBarber]

Battery/alternator fault?

Cannot see E10 being anything to do with this - it has a long term effect on the fuel system, no something that would cause a problem within a few days - certainly other things need to be ruled out before you starting thinking about the fuel system.