What is normal parasitic drain?
 

95 E320 I'm getting 0.45 MA battery is 5 years old won't start sitting for few days.Pulled battery charged it 12.7 V let it sit on bench few days it was at 12.2 V is this normal or do I need new battery? Motor running 14.5 V. Thanks

A fully charged lead acid battery will be ~ 12.66 V . A battery needs ~ 13.5 V applied in order to charge then let is sit for a few hours for the surface charge to dissipate before testing open circuit voltage.

What method did you use to get 12.7 ?

If the battery was 12.7 a few hours after a charge then dropped to 12.2 after a few days, the battery is failing. Try a load test as this will test capacity.

0.45 MA is almost nothing as it is sub 1 MA unless. Or do you mean 45 MA ( 0.045 A ) or 0.45 A , 0.45 A would be a lot.

Lowest setting on MM it's 0.044 A. I got 12.7 V 30 minutes after disconnected from charger right now battery is 12.47 V car will turn next day longer then they it turns slow thanks

That sounds like 44mA to me and that's fine; I wish I could get my 350mA down to that.

Assuming that's true, your battery sounds to be on its last legs.

RayH

With a 45ma drain, your battery should last for several MONTHS. If you want to get an exact number, look up Peukert's law and do the calculation yourself. A group 49 battery has a capacity of about 100AH@20A, and K=1.15.

You should have your battery load tested at any parts store, it can be weak even though it can be charged to 12.7v. The problem may also be caused by an intermittent draw from something like an alarm system or electric vacuum pump.

Thanks for the info guys. I took the battery to parts store where I got it from after charging it checked out ok that's why I did the parasitic drain test. I'll take the car and they can do load test. The battery was purchased 05/2010. I'll just get a new one. It must be toward the end. Thanks

You need a battery, my e320 94 can sit for 3 -4 weeks and start just fine

They can do a battery load test without the car. This puts a ~ 90 Amp load while monitoring voltage.

There are battery testers that have very small wires that check battery condition without a load but I call these inaccurate. Nothing beats an actual load while looking an an analog volt meter.