my 1100 7.2v nimh battery which came with my rc18t will only charge to 931 nimh what is the problem? my charger is a Ansmann Racing Xmove Deluxe

sounds normal and good. no problem.

so why will it not charge to 1100

It's hard to tell without testing the pack . It can be reduced capacity battery, possible remaining charge in battery when started, charger display inaccurate, battery not full, mis-rated pack, ect.

usualy most "smart" chargers today have a limit of capacity
see if it is set up for 100% or 90% at the NIMH AUTO charge mode
this is maybe why it wont go "fully charge"
or
creat your own charge cycle by setting up the correct parameters:

1100mAh
7.2V
6cell
1.2-1.4 per cell

start with a charge rate of 300-400mAH
and no more than 600mAh

see if it works

I wouldn't worry about how much charge went into the battery until you do a discharge at C/5 to 6.0 Volts and see how much the battery discharged.
Also most new Nimh need to be Form charged at C/10 for 14 to 16 hours to get best results from your battery pack.

Can I assume you already Form charged your battery?

what do you mean form charging? also I first charged it with the 10hour charger that came with it?

A FORM charge is a charge/discharge cycle of the battery at a charge rate of C/10 for 14-16 hours and discharge at C/5 (discharge rate is not as important as charge rate. This should be done 2-3 times before using the battery.
Below is from Hangtime Hobbies website, batteries is his business.


Q: What's up with 'Formation Charging'? Can't I just charge and fly a new pack?



A: The term 'Formation Charging' describes the initial charge/discharge 'forming' process that fully activates the 'chemical engine' and balances the cells in a new pack. NiMH packs have a particular need for repetitive c/10 charge/cycle conditioning, a 'break-in' procedure needed to get them to full rated capacity. Both NiMH and Nicad packs benefit from the process and the intent is to make sure that any new pack has been verified to be fully operational and that a 'start-up' capacity number is established for the pack before it's put into service. To 'Form' a new NiMH pack do three 10% 16-24 hour charges followed by a 300 to 500 ma discharge routine between each charge. In other words: Do a slow charge at the slow charge rate (or as close to it as you can reasonably get with your equipment) as shown on the pack label. Charge till the pack is warm, followed by a controlled discharge with a cycler. Do it 3 times. The recommended Formation Charge/ Slow Charge rate for our packs is printed right on the label of the pack as well as on the data card the pack was shipped with. New Nicad packs should get at least one slow charge followed by a 300 to 500ma discharge. Record the capacity numbers reported by your equipment for comparison cycling as the pack ages. Never check your brain at the door! As one respected modeler put it, "There's nothing more suspect than a new battery pack." Before you fly anybody's pack be certain it's fully operational and safe to fly.

ok thank you