Figure 1.  French Movement Phase      Figure 2. Hex B Unit List

The French 14e Dragoons with Gen. de Division Chastel were concealed from Prussian view.  The French have LOS to all hexes in the vicinity of the 4 batteries at A1 to A4.  Hex B is selected as an assembly point prior to charging because it is not exposed to any known ranged fire, and there is no evidence of a counter-charge threat.  Furthermore this hex exposes all four batteries to flank melee assault.  To get to Hex B, the 14e Dragons used road movement and split into squadrons in Hex B. Note that the skirmisher at Hex C was moved to allow the cavalry to pass across the bridge using road movement.  In Figure 3, the skirmisher was moved back to Hex C after the cavalry have passed. 

Paired squadrons can each charge two of the batteries:  the first squadron overruns and uncrews the battery, the second then melees it for a fatigue- and loss-free elimination.  Alternately, the French might try for an overrun of all four batteries, hoping to destroy them all in melee in the subsequent turn before Prussian forces could relieve the uncrewed batteries. 
 

Figure 3  French Charge Phase

French Charge Phase (Figure 3) 
Figure 3 shows that the batteries at A1, A3 and A4 had been limbered.  The battery at A2 remained unlimbered but its flank is exposed to a melee assault. The Prussian in his defensive phase has apparently  made an error assuming limbered artillery gives them a chance of getting away.  Limbered batteries are overrun and eliminated, not uncrewed like unlimbered batteries.  The task of the French is now made much simpler.  Rather than charging two batteries,  the cavalry can now remove all four by combination of overrun and melee. 

Specifically, the charges and melees are: 

• 75 man squadron charged, overran, and eliminated battery at A1
• 150 man squadron charged, stopped short of Battery A2, then meeleed and destroyed it in next phase
• 75 man squadron and Chastel charged but were stopped by supply wagon on the way to Battery A3.  The battery and the supply wagon were destroyed in the melee phase.
• 75 man squadron charged, overran, and eliminated battery at A4

1. Do not expose your batteries to a cavalry threat.
2. If you do expose your batteries to a cavalry threat, think twice before limbering them up.  You may be playing into your opponent's hands.
3. Accept that you are about to lose a lot of guns and take all possible steps to (a) minimise the losses and (b) make sure that you exact a hefty toll from your opponent's cavalry the following turn.
4. If your opponent leaves a clear charge route to a limbered battery, find that 25 man cavalry squadron with a fatigue of 9 and take that free charge to overrun and eliminate the battery.
5. Position your batteries with care, as they are a valuable asset.  Here a few tips.

• Use obstructed hexsides to protect them which cause cavalry to lose their charge bonus and they can not overrun the battery.
• Place a skirmisher with the battery facing in the appropriate direction to make the cavalry lose their flank attack bonus.  Note however, that if the hex is overrun instead of meleed, the skirmisher is gone just the same.